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Superacid studies : syntheses, structures and solution studies of Sb(III) and Sb(V) fluoro fluorosulfato… Zhang, Dingliang 1995

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SUPERACU) STUDIES: SYNTHESES, STRUCTURES AND SOLUTION STUDIES OFSb(ffl) AND Sb(V) FLUORO FLUOROSULFATO DERIVATWESbyDINGLIANG ZHANGM. Sc. The University of British Columbia, 1991B.Sc, Hangzhou University, Hangzhou, Zhejiang, China, 1982A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENT FOR THE DEGREE OFDOCTOR OF PHILOSOPHYINTHE FACULTY OF GRADUATE STUDIES(Department of Chemistry)We accept this thesis as conformingto the required standardcv,The University of British Columbia© D. ZHANG, June 1995In presenting this thesis in partial fulfilment of the requirements for an advanceddegree at the University of British Columbia, I agree that the Library shall make itfreely available for reference and study. I further agree that permission for extensivecopying of this thesis for scholarly purposes may be granted by the head of mydepartment or by his or her representatives. It is understood that copying orpublication of this thesis for financial gain shall not be allowed without my writtenpermission.(Signature)________________________________Department of__________________The University of British ColumbiaVancouver, CanadaDate 74tk%.3O 95DE-6 (2188)AbstractThe HSO3F/ bF5system (“Magic Acid”) was investigated by high resolution 19F 1Dand 2D NMR (COSY and J-resolved). Twelve fluoro-fluorosulfato-antimonate(V) specieswere clearly identified and the relative concentrations of these species were estimated based onthe integration of the 19F NMR signals for the HSO3F/ bF5systems with SbF5 concentrationranging from XSbFS = 0.000999 to XSbF5 = 0.342. The 1:1 and 1:2 complexes between HSO3Fand SbF5,[SbF5( O3F)] and[Sb2F10(ji-SO3)1,were found to be the principal species in thesystem. Other constituent species including the monomers, [SbF6], {SbF4( O3F)2],[SbF3( OF)j as well as the dimers, [Sb2F1i], [Sb2F9(ji,-SO3) and [Sb2F8Qi-SOF)(SO)2], were also found in the HSO3F/ bF5 system. Trimers of the type[SbF5-Qi-SOF)-SbF4(t- are present in systems with XF5O.O9S. All theoligomeric fluoro-fluorosulfato-antimonate(V) species were found to be SO3F-bridged ratherthan F-bridged.Based on the relative concentrations of the species in the HSO3F/ bF5 system, itappears that solvolysis of SbF5 in HSO3F is likely to occur in addition to the ligandredistribution. The byproduct HF reacts with Si02 to produce H20, which is protonated togive the oxonium ion H3O, which was observed in ‘H NMR spectra of the system. Anoxonium salt [H30][Sb2F1] was crystallized from the HSO3F/ bF5system with high SbF5content (xsbF5 0.342). The structure of [H30j[Sb2F1J is determined by single crystal X-raydiffraction. It has a very complex structure and the asymmetrical O-H . . F hydrogen bonds linkH3O and [Sb2F11j ions to form a 3-dimension network.Two new Sb(III) compounds, [SbF2( O3F)] and [SbF(SO3F)2], as well as[Sb(SO3F)31x, were prepared and their polymeric structures were determined to high precisionby single crystal X-ray diffraction. A detailed comparison for the series [SbFn(SO3F)3n] (n =0, 1, 2, or 3) provides an insight into the complex coordination chemistry of Sb(III) fluoridefluorosulfates. Fluoride functions as an asymmetrical bridging ligand and fluorosulfateIi.functions as an 0-tridentate asymmetrical bridging ligands. The overall coordination numberof antimony depends on the available donor sites of the ligands and accordingly increasesgradually from six for SbF3 to nine for [Sb(SO3F)].The Sb-O and Sb-F interactions in allfour compounds span a wide range from normal covalent bonds (1.9-2.1 A) to longintermolecular contact (‘- 3.0 A).In order to obtain structural information on superacid anions, single crystals of CsSO3F,Cs[H(SO3F)21,Cs[Au(SO3F)4],Cs2[Pt(SO3F)6],and Cs[Sb(SO3F)6]were prepared and theircrystal structures were determined by single crystal X-ray diffraction. The structures of thesuperacid anions are correlated to the weak nucleophilicity of anions and hence the acidstrength of the corresponding conjugate superacids. The new superacid anion [Sb(SO3F)6]ishighly symmetric and has exceptionally short S-O and S-F bonds at the periphery of the anion,From the structure of the anion, it is suggested that [Sb(SO3F)61 should be very weaklynucleophilic. The corresponding conjugate superacid, the HSOF/Sb(SO)5system, shouldbe a very strong superacid system.111TABLE OF CONTENTSAbstractTable of Contents ivList of Tables xList of Figures xiList of Symbol and Abbreviations xivAcknowledgments xviChapter 1 GENERAL INTRODUCTION 11.1 Superacid Concepts 11.2 Conjugate Superacids 21.2.1 Brönsted Acids Used in Conjugate superacids 31.2.2 Lewis Acids Used in Conjugate Superacids Binary Fluorides as Lewis Acids in Conjugate Superacids Binary Fluorosulfates as Lewis Acids in Conjugate Superacids Ternary Fluoride-Fluorosulfates as Lewis Acids in Conjugate Superacids 81.3 Syntheses and Characterizations of Inorganic Fluorosulfato-Derivatives 91.3.1 Syntheses of Inorganic Fluorosulfato-Derivatives 91.3.2 Characterization of Fluoro- and Fluorosulfato-Derivativesby Vibrational Spectroscopy Vibrational Spectra of Fluoro- and Fluorosulfato-Derivatives Characterization of Fluorosulfato-Derivatives by X-ray Diffraction 14iv1.4 Formulation of the Research Objectives 15Chapter 2 GENERAL EXPERIMENTAL 242.1 Introduction 242.2 Source of Chemicals Used in This Study 242.3 Apparatus and Equipment 242.3.1 Vacuum Lines 262.3.2 Dry Box 272.3.3 Glass Vessels 272.4 Purification and Preparation of Some Chemicals Used in This Study 292.4.1 Purification of HSO3Fand SbF5 292.4.2 Preparation of Bis(fluorosulfuryl) peroxide,S206F 302.5 Instrumentation and Methods 342.5.1 Elemental Analyses 342.5.2 Melting Point Determination 342.5.3 Infrared Spectroscopy 352.5.4 Raman Spectroscopy 352.5.5 X-ray Diffraction Studies 362.5.6 NMR Spectroscopy 362.5.7 Electrical Conductivity Measurements 38VChapter 3 A SOLUTION STJDY OF ANTiMONY PENTAFLUORIDE INFLUOROSULFURIC ACID 403.1 Introduction 403.2 Experimental 413.2.1 Preparation of NMR samples 413.2.2 ‘9F NMR Spectroscopy 413.2.3 Measurements of Spin-Lattice Relaxation Time T1 423.2.4 Conductivity Measurements of theHSO3F/MF(SO)5..(M=Sb, n=5 and M=Nb, Ta; n=4, 3) Systems 433.2.5 Single Crystal X-ray Diffraction of{H30][Sb2F1j 433.3 Results and Discussion 443.3.1 1D and 2D 19F- COSY spectroscopy 443.3.1.1 General Features of 1D ‘9F NMR Spectra of the HSO3F/ bF5System 453.3.1.2 Assignment of Monomeric Species 533.3.1.3 Assignment of Segments in the Oligomeric Species 593.3.1.4 Possible Oligomeric Species in the HSO3F/ bF5System 673.3.2 Electrical Conductivity Measurement, Spin-Lattice Relaxation Time T1and ‘H NMR Spectra of the HSO3F/ bF5System 723.3.3 Crystal Structure of[H30][ Sb2F11 773.4 Conclusion 81viChapter 4 THE SYNTHESES AND CRYSTAL AND MOLECULARSTRUCTURES OF ANTJMONY(II1) FLUORIDEFLUOROSULFATES [SbF(SO3F)..1(n=1, 2,3) 874.1 Introduction 874.2 Experimental 884.2.1. Syntheses of [SbF2( O3F)j 884.2.1.1 Reaction of Antimony with HSO3F 884.2.1.2 Solvolysis ofSbF2(0CH5)in an Excess of HSO3F 894.2.2 Synthesis of [SbF(SO3F)2] 894.2.3 Synthesis of [Sb(SO3F)] 904.2.4 X-Ray Crystallographic Analyses of [SbF2( O3F)j, [SbF(SO3F)2],and [Sb(SO3F)j 914.3 Results and Discussion 914.3.1 Synthesis 914.3.2 Molecular Structures of [SbF2( O3F)], [SbF(SO3F)2],and [Sb(SO3F)j 964.3.2.1 Description of the Molecular Structures 964.3.2.2 Structural Comparison of the Series [SbF(SO3F)3.njx 1024.3.2.3 Comparison to Other Related Structures 1074.3.3 Vibrational Spectra of [SbF2( O3F)]and [SbF(SO3F)2] 1094.4 Summary and Conclusions 114viiChapter 5 THE CRYSTAL AND MOLECULAR STRUCTURES OFCESIUM SALTS OF SOME SUPERACII) ANIONS 1205.1 Introduction 1205.2 Experimental 1225.2.1 Syntheses of CsSO3F,Cs[H(SO3F)21,Cs[Au(SO3F)4],Cs2[Pt(SO3F)6]andCs[Sn(SO3F)6] 1225.2.2 Synthesis and Characterization of Cs[Sb(SO3F)6] 1225.2.3 Preparation of Single Crystals 1235.3 Results and Discussion 1235.3.1 Syntheses of CsSO3F, Cs[H(SO3F)2j,Cs[Au(SO3F)4],Cs2[Sn(SO3F)6]andCs2[Pt(SOF)6] 1235.3.2 The Synthesis and Vibrational Spectra of Cs[Sb(SO3F)6] 1255.3.3 Description of Crystal Structures of CsSO3F,Cs[H(SO3F)2],Cs[Au(SOF)4],Cs2[Pt(SO3F)61,and Cs[Sb(SOF)6] 1275.3.4 Structural Comparison of the Superacid Anions [H(SO3F)21,[Au(SO3F)4},[Sb(SO3F)6],and [Pt(SO3F)6]2 1385.4 Conclusion 143Chapter 6 GENERAL CONCLUSiONS AND SUGGESTIONS FORFURTHER STUDIES 1476.1 General Conclusions 1476.2 Proposal for Further Studies 149viiiAppendix A Frequency Range of Vibration Bands of the SO3F Group in DifferentCoordination Modes 152Appendix B Calculated bond valence of Sb-O and Sb-F bondsin [SbF(SO3F)J(n0, 1, 2, 3) 153Appendix C List of Crystal Data and Structure Parameters for [H30][Sb2F1J 154Appendix D List of Crystal Data and Structure Parametersfor [SbF(SO3F)](n1, 2, 3) 166Appendix E List of Crystal Data and Selected Structure Parameters for CsSO3F,Cs[H(SO3F)21,Cs[Au(SO3F)41,Cs2[Pt(SO3F)6],and Cs[Sb(SOF)6] 181ixList of TablesTable 1-1 Physical properties of some Brönsted superacids. 4Table 2-1 Source and purity of chemicals. 25Table 2-2 Information on the NMR spectrometers. 36Table 3-1 Assignment of monomeric species forthe HSO3F/ bF5system with XFS=O.OO982 57Table 3-2 Assignment of ‘9F NMR signals (F(S) region) to segments inoligomeric fluoro-flurosulfato-antimonate(V) speciesin the HSO3F/ bF5system (xsbFs=O.0989) 65Table 3-3 Relative concentrations of monomeric species and segments inoligomeric species in the HSO3F/ bF5system 66Table 3-4 Proposed principal species and their relative concentrations inthe HSO3F/ bF5system 71Table 4-1 Bond distances and angles for the primary coordinationgeometries of the [SbF1( O3F)..](n3, 2, 1, or 0) 105Table 5-1 Frequency and relative intensity of vibrational bands (cm-I)for Cs[Sb(SO3F)6],Cs2[Sn(SO3F)6J,andCs2[Pt(SO3F)6] 127Table 5-2 Crystallographic data for Cs(SO3F), CsH(SO3F)2Cs[Au(SO3F)4],Cs[Pt(SO3F)6]and Cs[Sb(SO3F)6]. 128Table 5-3 Structure parameters of fluorosulfate anion in alkali metal fluorosulfatesand NH4SO3F. 130Table 5-4 M-O bond and 0 0 bond lengths in superacid anionsand related compounds. 139Table 5-5 Coordination environment of Cs in cesium salts of superacid anions. 143xList of FiguresFigure 2-1 Vacuum lines used in this study 26Figure 2-2 Some glassware used in this studies 28Figure 2-3 SbF5 storage ampoule 29Figure 2-4 Schematic diagram for the preparation of bis(fluorosulfuryl) peroxide. 31Figure 2-5 Flow reactors for the synthesis ofS206F 32Figure 2-6 JR gas cell 35Figure 2-7 Apparatus used in conductivity measurement 37Figure 3-1 19F NMR spectrum of the HSO3F/ bF5system (xsbF5=O.342)at 213 K 46Figure 3-2 Low temperature ‘9F NMR spectrum (F(S) region) of the HSO3F/ bF5system 48Figure 3-3 Low temperature ‘9F NMR spectrum (F(Sb) region) of the HSO3F/ bF5system 50Figure 3-4 Possible monomeric isomers of the type [SbF(SO3F)6..J andtheir corresponding spin systems 54Figure 3-5 ‘9F-’ COSY NMR spectrum of the HSO3F/ bF5systemwith XSbF5=O.000999 55Figure 3-6 19F- COSY NMR spectrum of the HSO3F/ bF5systemwith XSbF5O.OSOO 55Figure 3-7 ‘9F 2D NMR spectra of the HSO3F/ bF5systemwith XFSO.OOO999 60Figure 3-8 19F-’9COSY NMR spectrum of the HSO3F/ bF5systemwith XSbFSO.l94 63Figure 3-9 19F-’9COSY NMR spectrum of the HSO3F/ bF5systemwith XSbFSO.342 63xiFigure 3-10 Possible dimers of the type[Sb2F(SO3)11..]’andtheir corresponding spin systems 69Figure 3-11 Conductivities of theHSO3FIMF(SO), n=5; M=Nb, Ta; n=3,4) 73Figure 3-12 Spin-lattice relaxation time T1 of the HSO3F/ bF5system. 76Figure 3-13 Dependence of ‘H NIvIR chemical shits on SbF-concentrationin the HSO3F/ bF5system. 76Figure 3-14 Stereoscopic view of the unit cell of[H30]{Sb2F1J 78Figure 3-15 Molecular structures of[H30j[Sb2F1J 79Figure 3-16 FT-infrared spectrum of[H30][Sb2F1j 82Figure 4-1 Perspective view of the complete coordinationenvironment of Sb(III) in [Sb(SO3F)] 97Figure 4-2 Perspective view of the complete coordinationenvironment of Sb(III) in [SbF(SO3F)2J 97Figure 4-3 Perspective view of the complete coordinationenvironment of Sb(III) in [SbF2( O3F)] 98Figure 4-4 Perspective view of the complete coordinationenvironment of Sb(III) in [SbF3] 98Figure 4-5 Stereoscopic view of the unit cell of [SbF2( O3F)],[SbF(SO3F)2],and [Sb(SO3F)] 101Figure 4-6 Correlation between S-O bond and Sb-O bond distances 103Figure 4-7 Vibrational spectra of [SbF2( O3F)]with approximate descriptions ofthe vibrational bands 110xiiFigure 4-7 Vibrational spectra of [Sb(SO3F)]with approximate descriptions ofthe vibrational bands 113Figure 5-1 Vibrational spectra of Cs[Sb(SO3F)6] 126Figure 5-2 Structure of CsSO3F 129Figure 5-3 Structure of Cs[H(SO3F)2] 132Figure 5-4 Structure of Cs[Au(SO3F)4] 134Figure 5-6 Structure ofCs2[Pt(SO3F)6j 136Figure 5-7 Structure of Cs[Sb(SO3F)6j 137Figure 5-8 Structural comparison of SO3F group in superacid anions 141xliiLIST OF SYMBOLS AND ABBREVIATIONSH0 Hammettt acidity functionsolv solvatedXSbF5 mole fraction of antimony pentafluoridex mole fraction of Lewis acidXH3F mole fraction of HSO3Fm molality (mole/kg)In vibrational spectroscopy:v vibrational frequencyV vibrational stretching modeVsym symmetric vibrational stretching modev asymmetric vibrational stretching modep vibrational rocking mode6 vibrational deformation modet vibrational torsion modeS strong (intensity)m medium (intensity)w weak (intensity)v verysh shoulderb broadxivIn NMR Spectroscopy:FID Free Induction DecayT1 Spin-lattice relaxation time‘9F NMR chemical shift (ppm) reference to chemical shift of CFCI3 0&MS 1H NMR chemical shift (ppm) reference to chemical shift of TMS =0Notation system for the signals in the F(Sb) region of ‘9F NMR spectra of the HSO3F/ bF5system:S singletD doubletT tripletQ quartetq quintetN nonet (nine lines)For signals with same multiplicity, numbers are attached to indicate the order of theirappearance from low field to high field.xvACKNOWLEDGEMENTSI would like to express my sincere appreciation to my research supervisor, ProfessorFriedheim Aubke, for his inspiration, encouragement and guidance during my years ofgraduate studies.I also wish to thank Dr. S. J. Rettig and Professor J. Trotter of this Department for theirhelp in crystal structure determination. Professor Dr. G. Hagele and Mr. M. Heubes of theInstitut für Anorganische Chemie und Strukturchemie I, Heinrich Heine UniversitätDüsseldorf, Germany are thanked for their valuable collaboration in the NIvIR study.The members of my Guidance Committee, Professors R. C. Thompson, A. Storr andE. A. Ogryzlo are thanked for their constructive suggestions and helpful discussions. ProfessorG. Herring is thanked for the use of the Bruker AM 400 NMR spectrometer. Dr. 0. Chan andDr. N. Burlinson are thanked for their help and instruction with NMR techniques.My present and former co-workers Changqing Wang, Andrew Lewis, GermaineHwang, Dr. Shah Roshan Cader, Dr. Fred Mistry, Dr. Walter V. Cicha and Jun Xia are alsothanked for their help and enlightening discussions during my tenure.My gratitude is also extended to the exceptional service staff of this department.Ms. Liane Darge and Marietta Austria provided NMR services. Mr. Steve Rak designed andmade most of the glassware. Mr. P. Borda provided elemental analyses. Mr. Brin Powell,Brian, Bill, Ron, Rolly, Tom etc. in Mechanical and Electronic Engineering Services forconstructing and maintaining the equipment used for this research.Finally, I would like to thank my wife, Weihua Chen, for her kind understanding,invaluable encouragement and full support during my years of graduate study.xviChapter 1GENERAL INTRODUCTIONThe research work presented in this thesis involves the syntheses of Sb(V) and Sb(III)fluoro-fluorosulfato-derivatives and their roles in the development of novel HSO3F-basedsuperacid systems. In this chapter, a number of terms and concepts in superacid chemistry willbe discussed. This discussion is followed by a brief literature review and the formulation ofthis research project.1.1. Superacid ConceptsThe terms “acid” and “base” can be defined in different ways.’3 Each definition has itsstrong points and its weaknesses in particular chemical situations. The two most widely useddefinitions are those of Brönsted4 and Lewis5. According to Brönsted’s definition, acids aredefined as proton donors and bases as proton acceptors; however, this definition is restrictedto protonic solvents. In Lewis’ approach, acids and bases are defined as electron-pairacceptors and electron-pair donors respectively. Both definitions are used in this thesis and todistinguish between these two, the term “acid” will be prefixed with “Brönsted” or “Lewis”accordingly. However, the term “Lewis acids” will refer only to the molecular species such asSbF5 but not cationic species such as metal ions.Historically, the term “superacids” was first introduced in the chemical literature byHall and Conant6 in 1927 and it referred to strong protonic acids, e.g., H2S04that are capableof protonating weak bases such as certain organic carbonyl compounds. In the 1960’s,Gillespie7 defined superacids as acids that are stronger than 100% sulfuric acid. Thisdefinition, although somewhat arbitrary, has been widely accepted as the definition of theBrönsted superacids (or protonic superacids). On the commonly used Hammett acidityfunction scale (H0),8 the H0 value of 100% H2SO4 is -12. The H0 values of Brönstedsuperacids are more negative than -12 (or -H0> 12). The superacid concept has also been1extended to Lewis acids. Olah et al.9 defined Lewis superacids as Lewis acids that are strongerthan Aid3.There are several excellent reviews covering many aspects of superacid chemistry,9including the development and studies of superacid systems’° and their applications inorganic”12 and inorganic systems.’3’5 Only those publications closely related to this thesiswill be mentioned in the rest of this chapter.1.2. Conjugate SuperacidsA characteristic feature of Brönsted acids is their ionic dissociation via proton transfer,which is facilitated by strong hydrogen bonding. For example, a Brönsted acid, HA,autoionizes according to following equation:2HA .. H2A(soIv) + A(soIv) [1-11In the terminology of the solvent system concept,’6 the cation and anion are called the acidiumion and the base ion of the solvent system respectively. A strong Lewis acid Y can reduce theanion (K) concentration by converting K into a larger, less basic anion [AYf. The self-ionization equilibrium is now shifted to a higher acidium ion (H2A) concentration because ofthe formation of [AYf in a Lewis acid-base interaction:A(solv) + Y [AYf(solv) [1—2]The combination of [1-1] and [1-2] leads to the overall reaction:2HA + Y H2A(soIv) + [AYf(solv) [1-3]As a result, the acidity of a simple Brönsted acid can be greatly increased by the addition of astrong Lewis acid. If the resulting system is more acidic than 100% H2S04, it represents aconjugate Brönsted/Lewis superacid (hereafter abbreviated to conjugate superacid).The acidity of such a conjugate superacid system depends not only on the inherent acidstrengths of the Brönsted acid and the Lewis acid, but also on the concentration of the Lewis2acid. The conjugate superacid appears to have great potential for developing superacid systemsof very high acidity. So far, the strongest simple Brönsted acids are HSO3F and HF. Theyhave the same Hammett acidity function values (H0 = -15.1).’ The H0 of the “Magic Acid”,the 1:1 HSO3F/ bF5system, is estimated to be —‘ _21,18 which is significantly more negativethan that of pure HSO3F. Therefore, the search for new strong Lewis acids potentiallyapplicable to superacid systems has become a key to the development of novel superacidsystems.1.2.1 Brönsted Acids Used in Conjugate superacidsAs a component of the conjugate superacid system, the Brönsted acid used has to bereasonably strong, in order for the acidity of the conjugate system to surpass the limit set byGillespie’s definition. Some commonly used strong Brönsted acids listed in Table 1-1.Fluorosulfuric acid has the following advantages over the others:7”9(i) With a directly measurable H0 value of -15.1, fluorosulfuric acid is one of the strongestsimple monobasic acids known. The acid can be easily purified by distillation in astream of dry nitrogen at atmospheric pressure.(ii) Its liquid range, from -89°C to 163°C, provides a reaction medium over a wide andconvenient temperature range for the study of chemical reactions by NMR spectroscopy.(iii) Although fluorosulfuric acid attacks rubber, cork and wood, its inertness towards glassunder anhydrous conditions allows it to be handled in conventional glass or quartzapparatus. Self-dissociation into SO3 and HF, the reverse of the synthesis reaction, maypresent problems at elevated temperatures but is negligible at room temperature.(iv) Compared to H2S04,HSO3F has a much lower viscosity (close to the viscosity ofwater), so that manipulations such as filtration or decantation are easier.For all these reasons, HSO3F, is the most widely used Brönsted acid in conjugatesuperacid systems’839 besides HF. HSO3Fwas also used in the present work.3Table 1-1 Physical properties of some Brönsted superacids.Properties HC1O4 HF* HSO3F HSO3C1 HSO3CFmeltingpoint -112 -89.9 -89 -81 -34(°C)boilingpoint 110 19.5 162.7 151-152 162(°C) (explosive)density 1.767 1.002 1.726 1.753 1.698(g/cm3) (20°C) (0°C) (25°C) (25°C) (25°C)viscosity - 0.256 1.56 3.0 2.87(cp) (0°C) (25°C) (15°C) (25°C)dielectric constant - 84 120 60± 10(0°C) (25°C) (25°C)conductivity - 10’6 (0°C) 1.1x104 2-3x10-4 2x104(ohm1.c) (20°C) (20°C) (20°C)H0 —-13.0 -15.1 -15.1 -14.1 -13.8* Data for HF are from reference 40 except the H0 value, which is from reference 17. All other data are fromreference Lewis Acids Used in Conjugate SuperacidsSince the anions of strong Brönsted acids are generally of high electronegativity, lownucleophilicity and poor coordinating ability, the Lewis acid in a conjugate superacid shouldhave a central atom in a high oxidation state coordinated by highly electronegative ligands, e.g.F, C1 or S03F, etc. The Lewis acids may have oligomeric structures in the absence of Lewisbases. Ideally, however, these oligomers should break up in solution. The central atom shouldnot have readily accessible lower oxidation states to avoid redox reactions as side reactions. Binary Fluorides as Lewis Acids in Conjugate SuperacidsThe most interesting and important group of Lewis acids are binary fluorides ofelements in Groups 4, 5, 13, 14, and 15. Among these binary fluorides, pentafluorides of4Group 5 and Group 15 elements show exceptional Lewis acidity. Their use as Lewis acids inconjugate superacids has been extensively documented.20’22, 26-36, 4145 The relative Lewis acidstrengths of the pentafluorides in HF or HSO3Fincreases in the following order:PF5<NbF5<TaP5<AsF5< SbF5 in HF 17,43PF5 NbF5<TaF5<AsF5<BiF5 < SbF5 in HS0326’7°The strongest of the above Lewis acids, antimony pentafluoride, has a polymeric chainstructure with cis-fluorine-bridges in the liquid phase. In the solid state, it has a tetramericstructure similar to [NbF5]4and [TaF5]4.6 Its solutions in HF20’ 33, 41.43 and HS03F22’27-35 areprobably the most thoroughly investigated and the most widely used conjugate superacids.Due to the intrinsic strong Lewis acid strength of SbF5 and the limited corrosiveness ofHSO3Ftowards glassware, much attention has been drawn to the studies of the HSO3F/ bF5system. In electrical conductometric studies, the interpretation of conductivity of the system isbased on the observation that the acidium ion,H2SO3F,and the base ion, SO3F, are the mostmobile ions in HSO3F-based conjugate superacids.’9 Thus in dilute solution, the conductivityof the solution may reflect the relative acidium ion or base ion concentration and titrationagainst strong base such as KSO3F determines the acidic or basic dissociation modes of asolute in the solution. Previous conductivity measurements have been carried out for theHSO3F/ bF5system in a low Lewis acid concentration range (<0.8 mol/kg).22 The resultsshow that the HSO3F/ bF5system is a strong monobasic acid.22 Hammett acidity function H0values, reflecting the overall protonating ability, have been determined for the HSO3F/ bF5system as a function of SbF5 content, using different methods.27’334 Although NMRspectroscopy has been introduced as a replacement for UV-vis spectroscopy to determineionization ratios of the base indicator either by the chemical shift method or by the integrationmethod,16”89’27 difficulties remain at high acidity, resulting from the unavailability ofsuitable Hammett bases. Gold and coworkers34’5 applied 1H NMR line-shape analysis toextend H0 measurements to a solution of 90 mole% SbF5. However, the use of large amounts5ofH20 (up to 59 mole%) as the indicator35 raises the question about its effects on the chemicalcomposition of the system and hence the validity of the method. Nevertheless, allmeasurements indicate that the H0 values of the HSO3F/ bF5conjugate superacid increases asthe SbF5 concentration increases at least up to Ca. 50 mole%, for which the H0 was estimatedto be 22±0.5.10 It is believed that this H0 value represents the highest acidity in HSO3F-basedsystems, which is leveled by the acidium ionH2SO3F. 10Fluorine-19 NMR spectroscopy has also been employed to obtain information onstructures of the chemical species present in the HSO3F/ bF5system. The studies conductedby Thompson et aL22 for 1.7 SbF5 solution in HSO3F, by Commeyras and Olah28 forHSO3F/ bF5over the SbF5/HSO3Fratio range of 0.4 1.4, and by Dean and Gillespie43 for aSO2CIF-diluted mixture of HSO3F and SbF5 (SbF5:HSO3F 0.92:1.00) indicated theprincipal species present in the systems are monomeric [SbF5( O3F)] and SO3F-bridged[Sb2F10Qi-SO3)f. Other species such as [SbF6J, 28 F-bridged [Sb2F1ir 28, 43, and cis- andtrans-[SbF4QJ.,- OF) were also observed by ‘9F NMR spectroscopy. However, the latestand most extensive 19F NIvIR study by Brunel et al.29 in 1978 concluded that the main speciesare H[Sb11F5(SO3)] where SbF511 has a cis-F-bridged polymeric structure and that SO3F-bridged H[Sb210(SOF)] is present only for small ratios of SbF5 to HSO3F. Thisobservation29is contrary to the previous studies22’843 and also contradicts the conclusion fromthe studies of ternary fluoride fluorosulfates using vibrational spectroscopy475’that thefluorosulfato group always takes precedence over fluorine as a bridging ligand. Binary Fluorosulfates as Lewis Acids in Conjugate SuperacidsThe fluorosulfate radical, SO3F•, and the fluorosulfate anion, SO3F, have been called a“pseudohalogen” and “pseudohalide” respectively because their chemistries resemble those ofthe halogens and halides. With regard to electronegativity and coordinating ability, thefluorosulfate anion resembles the fluoride ion more than the chloride ion. Theelectronegativity of the fluorosulfate group has been estimated to be 3.83 on the Pauling scale6(F, 3.98; Cl, 3.16) from‘19Sn Mössbauer studies ofK2[SnX6Jwith X=F, Cl, SO3F.52 The Taftinductive constant (0*) is a measure of the electron inductive effect. In comparison with the0* values of CH3, F, Cl, and Br (a*0, 3.08, 2.94, and 2.80 respectively), the o value of theSO3F group is found to be 3.68 from Mössbauer studies ofX2SnF andX2Sn(SO3F)(X =CH3, F, Cl, Br).53 This result indicates that the SO3F group has a greater ability to withdrawelectronic charge via both-and it-interactions than fluorine. This has been explained as aconsequence of the fact that the electronic charge can be delocalized over the entire SO3Fgroup. Similar ligand field splitting parameters (Dq) of the fluorosulfate and fluoride ionsindicate that they are both weak field ligands.54 The fluorosulfate anion is capable ofpolydentate coordination and, such as F, can function as a bridging ligand. Because of theresemblance of fluorosulfates to fluorides, binary fluorosulfates should form another group ofgood Lewis acids, potentially applicable in the BrönstedfLewis superacid systems. Theirchemistry in HSO3F is expected to be less complicated than that of binary fluorides becauseligand exchange between solute and solvent does not cause a change in composition.The application of the binary fluorosulfates as Lewis acids in HSO3F-based conjugatesuperacids is limited, since most of the known binary fluorosulfates with the metals in highoxidation states are either not sufficiently soluble in HSO3F or are thermally unstable. Fromthe high strengths of the Lewis acids BF3 and AIF3, one would expect the correspondingfluorosulfates to be strong Lewis acids as well. Unfortunately, tris(fluorosulfate)s of all thegroup 13 elements are insoluble in HSO3F.5557 Sn(SO3F)458 is also insoluble, although itspotential Lewis acidity is suggested by the formation of M2[Sn(SO3F)6J(M=K, Cs).59Surprisingly, Pb(SO3F)4 exhibits basic behavior in HSO3F.6° No binarypentakis(fluorosulfate)s of Group 15 elements have been reported. Among transition metalfluorosulfates,6’Au(SO3F)7’ and Pt(SO3F)49 are soluble in HSO3F and form conjugatesuperacids with HSO3F. Ir(SO3F)4is soluble in HSO3F but no solution studies have beenreported, probably due to the difficulty in its preparation.62 More recently, two novel superacidsystems, HSO3F/Ta(SO)5(solv.) and HSO3F/Nb(SO)5(solv.), were obtained by the7oxidation of the corresponding metals with S206Fin HSO3Fbut attempts to isolate the purecompounds, Nb(SO3F)5 and Ta(SO3F)5,were unsuccessful.63 Compared to HSO3F/ bF5(“Magic Acid”), the order of Lewis acidity of these binary fluorosulfates in HSO3F isestimated to be as follows:Pt(SO3F)4> Au(SO3F)> Ta(SO3F)5(solv.) > SbF5 > Nb(SO3F)5(solv.)The estimation is based on the comparison of the slopes of electrical conductivity versus Lewisacid concentration plots and of the titration curves obtained by titration of the acid against thebase KSO3F. Ternary Fluoride-Fluorosulfates as Lewis Acids in Conjugate SuperacidsPrevious studies of the ternary system HSO3F/ bF5/S0have shown that the acidity ofa solution of SbF5 in HSO3F can be enhanced by the addition of SO3.22 The acidity of thesolution increases with the amount of SO3 added, up to a maximum of three moles of SO3 permole of SbF5. A similar phenomenon was observed for HSO3F/AsF5/S0.26 The increase inacidity is presumably due to the formation of complex Sb(V) fluoride fluorosulfate acids of thetype H[SbF(SO3F)6.](n=2, 3, 4), suggesting an in situS03-insertion reaction:SbF5 + (5-n)S03.. SbF(SO3F)5 [1-4]This postulation is supported by NMR studies of the solutions in HSO3F22 and by thesyntheses of their ansolvo acids SbF4(SO3F),7’48 SbF3(SOF)2,48 Sb29(SOF),48 andAsF3(SOF)2.49 These reports imply that ternary fluoride fluorosulfates could be anothergroup of potentially useful Lewis acids in conjugate superacid systems. It is also interesting tonote that in the series of compounds with the general formula SbF(SO3F)5(n > 2), theLewis acid strengths in fluorosulfuric acid increases as n decreases,22 i.e., the higher thefluorosulfate content, the stronger the Lewis acid.It has been found that this trend, initially reported for HSO3F/MF5/S0 (M=As,Sb), isgenerally applicable to the binary systems HSO3F/MF(SO)5(MNb, Ta; n=O, 3, 4, 5) as8well.64 Instead of using in situ S03-insertion of the corresponding fluorides, a one-step metaloxidationiligand redistribution reaction has been developed to synthesize the Lewis acidsniobium(V) and tantalum(V) fluoride fluorosulfates according to the following equation:5°nMF5 + (5-n)M + excessS206F 5M F(SO3).. [1-5]Five niobium(V) and tantalum(V) fluoride fluorosulfates—Nb29(SOF),NbF4(SO3F),NbF3(SOF)2,TaF4(SO3F) and TaF3(SOF)2—were synthesized in this manner and purifiedby distillation in vacuo. The Nb(V) and Ta(V) fluoride fluorosulfates isolated are misciblewith HSO3F in any proportion, thereby allowing conductivity measurements over the entireconcentration range. A preliminary conductometric study showed that TaF3(SOF)2is a weakLewis acid in HSO3F.64 NbF3(SOF)2,NbF4(SO3F)and TaF4(SO3F) are found to behave asvery weak electrolytes and poor S03F acceptors. 641.3. Syntheses and Characterizations of Inorganic Fluorosulfato-Derivatives1.3.1 Syntheses of Inorganic Fluorosulfato-DerivativesThe synthetic chemistry of inorganic fluorosulfato-derivatives has been extensivelyreviewed.61’569 A number of synthetic approaches have been developed over the years,including:(i) Oxidation of metal and low valence compounds by S206For XSO3F (X=F, Cl, Br) inthe presence or absence of HSO3F. For example, gold tris(fluorosulfate) can besynthesized by oxidation of gold withS206F:2 Au + 3S206F HSO3F 2 Au(SO3F) [1-6](ii) Solvolysis of other salts (halides or carboxylates) in HSO3F. The by-products should bevolatile or very soluble in HSO3F, allowing easy isolation of the product. This method isusually applied in the preparation ionic or low valence fluorosulfates,69 such as alkalimetal fluorosulfates:9KCI + HSO3F KSO3F+ HCI [1-7](iii) Oxidation of chlorides byS206F. This route is of limited use since the further reactionofS206Fwith the by-product, Cl2, produces C1SO3Fand CIO2S3F. The latter is verydifficult to separate from the product. In addition, the oxidation of chlorides is often notcomplete, as seen in the following reaction:7°SbCl5 + SO6F2 f Cl + SbCl5(SO3F) (x 4) [1-8](iv) S03-insertion reaction of fluorides.69 This method is limited mainly to alkali and alkalineearth fluorides, e.g.:NaF + SO3 - NaSO3F [1-9]The reaction is often incomplete for other fluorides with high lattice energies.(v) Metathesis of silver fluorosulfates with other halides. This method has been successfullyused in the preparation of Re(CO)5S03F:71Re(CO)5Cl+ AgSO3F CH2C12 Re(CO)5S03F+ AgCI [1-10]The driving force for the reaction is the formation of silver(I) halide which is insoluble inCH2I.The appreciable solubility of Re(CO)5S03Fin CH2I allows an easy isolationof the product from AgC1.(vi) Reaction ofS205Fwith a metal oxide or alkoxide. The reaction ofS2O5Fand Bi203produces a binary fluorosulfate, Bi(SO3F):72Bi203 + 3S205F 24 days 2Bi(SO3F) [1-111However, the reaction with Ti(OCH3)4gives a disubstituted product, Ti(OCH3)2(SOF)indicating the limited fluorosulfonating ability ofS205F:72Ti(OCH3)+ 2S05F 6 Ti(OCH3)2(SOF)+ 2CH3OSOF [1-12]10(vii) Decomposition of binary fluorosulfates. Some high valence binary fluorosulfates are notthermally stable. During the preparation or upon heating, they may decompose to give:a) low valence binary fluorosulfates via reductive elimination of the S03F radical toform S206F; b) oxyfluorosulfates by elimination of S205F; or c) fluoridefluorosulfates through loss of SO3:2Ag(SO3F) 210 C 2AgSO3F+S206F [1-13]2 Re + 7S206F 2 Re03(SOF)+ 6S205F [1-14]2 Nb + 5 S206F 25 C 2 NbF(SO3F)s+ 2x SO3 [1-151The decomposition of binary fluorosulfates can also give sulfates or oxides as products.Most of the fluorosulfato-derivatives are prepared by routes (1) and (ii), involving the use ofHSO3F and S206F. The oxidizing agent, bis(fluorosulfuryl) peroxide, S206F is misciblewith HSO3F. The weak 0-0 bond, linking two S03F radicals, is easily cleaved andS206Facts as a two-electron oxidant according to:S206F . 2SO3F [1-16]2S03F + 2e 2S03F [1-17]giving rise to a rich synthetic chemistry.1.3.2 Characterization of Fluoro- and Fluorosulfato-Derivatives by VibrationalSpectroscopyStructural information on inorganic fluorine-containing compounds can be acquired byvarious physical techniques. Vibrational spectroscopy (infrared and Raman) has been the mostwidely used technique to gain initial structural information since the spectrometers are readilyavailable and the sampling procedures are uncomplicated. It can be conveniently used for thestudy of solids, liquids, solutions or gases. In Raman spectra, only the fundamental vibrations11are usually observed. Overtones or combination modes are often too weak to be observedunless Fermi resonance occurs. Unlike infrared spectroscopy, Raman spectroscopy does notrequire the use of specific window materials, which may react with the compounds studied. Insome instances, however, intense colors or limited thermal stability of compounds or theoccurrence of fluorescence can prevent the recording of Raman spectra, even though the adventof lasers, particularly infrared lasers, as excitation sources has widened the range of compoundswhich can be studied using this technique.For solid compounds, single crystal X-ray diffraction is one of the most definitivetechnique for accurate structure determination. However, the high reactivity of fluorine-containing compounds has frequently prevented the preparation of single crystals and haslimited crystallographic studies. Mössbauer spectroscopy is applicable to a limited number ofcompounds containing nuclei such as 57Fe and 119Sn. NMR spectroscopy has been usedextensively for liquid compounds and solutions, and it is now possible to use this technique tostudy solids. Vibrational Spectra of Fluoro- and Fluorosulfato-DerivativesThe vibrational spectroscopy of binary fluorides has been extensively reviewed.74 Thespectra of inorganic fluoride may be interpreted in terms of group frequencies. The bandpositions may be broadly defined for a neutral binary fluoride as the terminal stretching region(600-800 cm), the bridging stretching region (400-600 cm1) and the deformation moderegion (100-400 cmI). The analysis of the vibrational bands on the basis of group-frequencytreatment is therefore relatively simple for binary fluorides, provided the above mentionedband positions are not obscured by other internal bands or lattice modes. Slight complicationsmay arise with lighter central atoms and ionic species. As a general rule, bands of anionicfluoride derivatives are observed at lower frequencies while those of cationic fluoridederivatives shift to higher frequencies, relative to comparable neutral fluorides.12The vibrational analysis of the fluorosulfate group is based on its local symmetry andbond strengths. The fluorosulfate group may be assumed to exhibit at least five differentbonding or coordination modes: (a). ionic; (b). covalent monodentate; (c). covalent bidentate;(d). covalent tridentate; and (e). covalent tetradentate. Bonding to other atoms occurs throughthe more basic oxygens except in the case of the tetradentate mode, where fluorine is involvedas well.For the symmetrical coordination modes of SO3F groups, the vibrational analysis iscomparatively easy. The SO3F with ionic, tridentate, and tetradentate coordination modes haveC3, local symmetry. For the remaining bonding or coordination modes, C local symmetry isexpected. This difference is reflected in the number of fundamentals: six for C3 and nine forC5 or lower point groups, with all bands infrared and Raman active. Within the two“symmetry groups”, differences in band positions due to varying bond strengths allow areasonable differentiation. The analysis is usually focused on the stretching region(700-1500 cm) because the stretching bands are spread over a wider spectral range, and henceare more diagnostic than deformation modes. A diagram correlating the vibrationalfrequencies and coordination modes of SO3F group is given in Appendix A.If the SO3F group is in an asymmetrical multidentate coordination mode, thevibrational analysis becomes difficult. In such coordination modes, the three S-O bonddistances are different. The local symmetry of the SO3F group is further lowered to C1symmetry. However, the number of fundamentals are the same as for Cs symmetry. Thedifferentiation between Cj and C symmetry is almost not feasible without knowledge of thestructure of the compound to be analyzed.Caution is required when spectra are obtained from solid samples. For example,secondary bonding is a common phenomenon in solid state compounds. Such interaction maylower the local symmetry of SO3F. Its effect on the vibrational spectra depends on the extentof the interaction (see Chapter 4). In addition, a number of factors, termed solid state effects,13may cause band splitting. Among these factors, site symmetry and factor group splitting arethe most prominent. Another complication arises if the unit cell contains more than one type offluorosulfate ion with slightly different local symmetries due to the orientations of cations andanions. In this situation, all or most of the fundamentals will be duplicated, regardless ofsymmetry, as in Sn(SO3F)2.751.3.2.2 Characterization of Fluorosulfato-Derivatives by X-ray DiffractionFor inorganic fluorides, much use has been made of both single crystal and powderX-ray diffraction studies. For inorganic fluorosulfato-derivatives, in contrast, only a limitednumber of crystal structures are available and powder X-ray diffraction is not used to asignificant extent because of the difficulty in inferring structural information. The knowncrystal structures can be divided into the following categories:(i) Ionic fluorosulfates. The structures of KSO3F,76 NH4SO3F,77 and LiSO3F78 weredetermined in the 1960’s and 1970’s. Other ionic fluorosulfates with known structuresare[S4N1( O3F)2,79[SN4]( O3F)2,8°and[Se10}(SO3F)2.8’(ii) Fluorosulfato-derivatives of p-block elements including [I(SO3F)2]I,82 two xenon(II)fluorosulfato-derivatives— [(XeF)2S03F][AsF6]83 and FXeSO3,84 an organometallicfluorosulfate, (CH3)2Sn(SOF)85 and a recently reported binary fluorosulfate,Sn(SO3F)2.86(iii) Transition metal fluorosulfato-derivatives. The crystal structure of [Au(SO3F)]287is theonly known crystal structure of binary transition metal fluorosulfates. Recently, a groupof fluorosulfates of carbonyl species, [cyclo-Pd2Qi-CO)](S3F)88 cisPd(CO)2(S3F),89and mer-Ir(CO)3(SO3F)9°have been reported.(iv) Fluorosulfates involving hydrogen bonding such as the 1:1 complex between acetic acidand fluorosulfuric acid9’ and the mono-solvated fluorosulfate Cs[H(SO3F)21.9214Many solid inorganic fluorosulfato derivatives, especially binary fluorosulfates andfluoride-fluorosulfates, are insoluble in HSO3Fand lack appreciable volatility, presumably dueto the high degree of polymerization. These properties have frequently precluded thepreparation of single crystals suitable for X-ray diffraction studies. For the compoundsanticipated to form single crystals, the high reactivity of the compounds can present difficultiesduring the preparation of single crystals. Because of these difficulties, single crystals X-raydiffraction studies have not been widely employed in the structural characterization of solidfluorosulfato-derivatives.1.4. Formulation of Research ObjectivesThe H0 determination by different research groups27’334indicated that H0 values of theHSO3F/ bF5 conjugate superacid increases as SbF5 concentration increases at least up toCa. 50 mole% (or mole fraction of SbF5, xsbF5=O.S). Although it has been suggested that theacidity in HSO3F-based systems is leveled by the acidium ion H2SO3F,’° the question ofwhether a higher concentration of complex acids formed at very high Lewis acid concentrationoffers even higher acidity is still open. The reliable determination of H0 values at high acidityawaits the discovery of new suitable Hammett bases or novel methods.The HSO3FIMF11(S)5..(MNb, Ta; n=3, 4) systems exhibit maximal conductivityat the mole fraction of Lewis acid xLA=O. 1 8—’0.20, regardless of the different acid strengths ofthe Lewis acid.64 It was interesting to determine whether the HSO3F/ bF5system, a muchstronger conjugate superacid than the above systems, behaves similarly.Previous NMR studies carried out 15 years ago on the HSO3F/ bF5 conjugatesuperacids resulted in different conclusions.22’28, 29, 36 The advent of FT-NMR and thesubsequent development of various 2D NIVIR methods provided powerful tools for studying thestructures of species in solutions. It was hoped that the application of high-resolution 1D NMRand 2D NMR to the HSO3F/ bF5system would yield unambiguous results and enable the15determination of the structures of the species present in the system and the detailedcomposition of the system.The synthesis of new, strong Lewis acids plays a very important role in thedevelopment of novel conjugate superacids. From the progressively stronger Lewis acidstrengths in the order of SbF5 , SbF4(SO3F) and SbF3(SOF)2,it would be expected thatSb(SO3F)5might be the strongest Lewis acid in HSO3F. While the HF/SbF5 system had beenextensively studied, its counterpart in HSO3F-based systems—HSO3F/Sb(SO) andcorresponding Lewis acid Sb(SO3F)5were virtually unknown.From the facts that MF(SO3F)5..(M=Nb, Ta; n= 3, 4) can be obtained by the one-stepoxidative-addition/ligand-redistribution reaction50 while the in situ S03-insertion does notoccur in the ternary HSO3FINbF5/S0 system,26 it might be suggested that the former routeshould be more efficient than the latter in terms of the synthesis of SbF(SO3F)5.of highS03F/F ratio. The reaction of SbF5 in excess SO3 was reported to give a complicatedmixture of products and the reaction of SbF5 and SO3 in 1:2 mole ratio gave SbF4(SO3F)as anisolated product.47 It seemed promising to extend the general method of synthesis of Nb(V)and Ta(V) fluoride fluorosulfates (equation [1-5]) to the preparation of Sb(V) fluoridefluorosulfates and Sb(SO3F)5. The use of excess S206F instead of HSO3F as a reactionmedium would allow easier isolation of the product.At the onset of this study, attempts to obtain antimony pentakis(fluorosulfate)s by thereaction ofS206Fand antimony were not successful. The reaction unexpectedly produced awhite precipitate at initial stages and a gray, sticky mixture finally. It was concluded that theoxidation of elemental antimony with excessS206Fwould not be feasible for the preparationof Sb(SO3F)5. The white precipitate formed during the initial stage of the reaction, possibly alow valence antimony species, apparently interfered with further oxidation of antimony tooxidation +5. In addition to the stable Sb(III) compounds, a few species with antimony inunusual oxidation states have been reported to exist in solution or in the solid state. The16existence of a yellow Sb species and a blue Sb species upon oxidizing Sb withS206FinHSO3F were reported based on the resemblance of their UV-vis spectra to those of andGillespie et al.94 followed this reaction but could not repeat the result and found thatthe oxidation of Sb with S206Fin HSO3Fgave a white compound, Sb(SO3F).The reactionof antimony with HSO3Fgave a white solid which was analyzed as Sb(SO3F). However, allthese possible low valence antimony compounds, including the interesting compoundSb(SO3F) with antimony in the unusual +1 oxidation state, were only characterized byelemental analysis. The confusion surrounding these low valence antimony species should beresolved before further attempts are made to synthesize and isolate Sb(SO3F)5.The oxidation of SbF3 by S206F or FSO3 to give SbF4(SO3F) or SbF3(50F)2respectively according to:48SbF3 +S206F SbF3(SOF)2 [1-18]SbF3 + FSO3 - SbF4(SO3F) [1-19]might serve as templates for the preparation of SbF2(SO3F),SbF(SO3F)4and Sb(SO3F)5.However, two of the candidate precursors, SbF2(SO3F)and SbF(SO3F)2,are unknown and theother precursor, Sb(SO3F)95 has only been reported in a short communication withoutdetailed characterization.Based on above discussion, the objectives of the research program are:(i) To study the SbF5IHSO3F system by means of conductivity measurements andmultinuclear NMR spectroscopic techniques including 1D and 2D NMR (‘9F COSY andJ-resolved) and T1 measurements.(ii) To re-investigate the reactions of antimony with HSO3F to confirm the existence of thereported fluorosulfato-derivatives with antimony in oxidation states lower than +3 and todetermine and characterize the possible intermediates in the oxidation process from Sb(O)to Sb(V) in the reactions of antimony in excessS206F. These fluorosulfato-derivatives17of low valence antimony might also serve as precursors for the synthesis of antimony(V)fluoride fluorosulfates of high S03F7F ratio.(iii) To obtain evidence for the existence of the potentially strong conjugate superacid, theHSO3F/Sb(SO)5system. Isolation of salts containing the complex anion [Sb(SO3F)6],for example, would suggest the possible existence of the conjugate superacid system. Inaddition, the anion itself was expected to be very weakly nucleophilic and might beuseful in stabilizing unusual cations in organic and inorganic synthetic chemistry.(iv) To make an effort to grow single crystals of important solid compounds encountered inthis study. In the past, the characterizations of most fluorosulfato-derivatives have reliedmainly on the elemental analysis and vibrational spectroscopy. Single crystal X-raydiffraction would yield the most detailed and precise information on the molecularstructure of these solid fluorosulfato derivatives. 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Commun. 1971, 1376.47. Gillespie, R. J.; Rothenbury, R. A. Can. J. Chem. 1964, 42, 416.48. Wilson, W. W.; Aubke, F. J. Fluorine Chem. 1979, 13, 431.49. Imoto, H.; Aubke, F. I Fluorine Chem. 1980, 15, 59.50. Zhang, D.; Aubke, F. J. Fluorine Chem. 1992, 58, 81.51. Willner, H.; Mistry, F.; Aubke, F. J. Fluorine Chem. 1992, 59, 333.52. Leung, P. C. Ph.D. Thesis, The University of British Columbia, 1979.53. Yeats, P. A.; Sams, 3. R.; Aubke, F. Inorg. Chem. 1973, 11, 2634.54. Edwards, D. A.; Stiff, M. J.; Woolf, A. A. Inorg. Nucl. Chem. Lett. 1967, 3, 427.55. Singh, S.; Verma, R. D. Polyhedron 1983, 2, 1209.56. Storr, A.; Yeats, P. A.; Aubke, F. Can. I Chem. 1972, 50, 452.57. Paul, R. C.; Sharma, R. D.; Singh, S.; Verma, R. D. J. Inorg. Nuci. Chem. 1981, 43, 1919.58. Yeats, P. A.; Poh, B. L.; Ford, B. F. E.; Sams, 3. R.; Aubke, F. J. Chem. Soc. (A) 1970,2188.2159. Mallela, S. P.; Lee, K. C.; Aubke, F. Inorg. Chem. 1984, 23, 653.60. Carter, H. A.; Mime, C. A.; Aubke F. J. Inorg. Nuci. Chem. 1975, 37, 282.61. Aubke, F.; Cader, M. S. R. and Mistry, F. in Synthetic Fluorine Chemistry; Eds. G. A.Olah, R. D. Chambers and G. K. S. Prakash; Wiley: 1992, p 43. and References therein.62. Lee, K. C.; Aubke, F. J. Fluorine. Chem. 1982, 19, 501.63. Cicha, W. V.; Aubke, F. J. Am. Chem. Soc. 1988, 111, 4328.64. Zhang, D. M. Sc. Thesis, The University of British Columbia, 1991.65. Lawrence, G. A. Chem. Revs. 1986, 86, 17.66. Aubke, F.; DesMarteau, D. D. Fluorine Chem. Revs. 1977, 8, 73.67. DaMarco, R. A.; Shreeve, J. M. in Advances in Inorganic Chemistry and Radiochemistry;Eds. Emelèus, H. J.; Sharpe, A. G.; Academic Press: New York, 1974, Vol. 16, p 109.68. Jache, A. W. in Advances in Inorganic Chemistry and Radiochemistry; Eds. Emelèus, H. J.;Sharpe, A. G., Academic Press: New York, 1974, Vol. 16, p 177.69. Woolf, A. A. in New Pathways in Inorganic Chemistry; Eds. Ebsworth, E. A. V.;Maddock, A. G.; Sharpe, A. G.; Cambridge Univ. Press: Cambridge, U. K., 1968, p 327.70. Noftie R. E.; Cady, G. H. J. Inorg. Nucl. Chem. 1967, 29, 1967.71. Mallela, S. P.; Aubke, F. Inorg. Chem. 1985, 24, 2969.72. Niyagi, D. G., Singh, S. and Verma, R. D. Can. J. Chem. 1989, 67, 1895.73. Cicha, W. V.; Herring, F. G. Aubke, F. Can. J. Chem. 1990, 68, 103.74. Reynolds, D. J. in Advances in Fluorine Chemistry; Eds. Stacey, M.; Tatlow, J. C.; Sharpe,A. G; Butterworths: London, 1973; Vol. 7, p 1.75. Alleyne, C. S.; Mailer, K. 0.; Thompson, R. C. Can. .1. Chem. 1974, 52, 336.76. O’Sullivan, K.; Thompson, R. C. Trotter, 3. J. Chem. Soc. (A) 1967, 2024.77. O’Sullivan, K., Thompson, R. C.; Trotter J. J. Chem. Soc. (A) 1970, 1814.78. Z. Zak and M. Kosicka Acta. Crystallogr. 1978, B34, 38.2279. Gillespie, R. J.; Kent, J. P.; Sawyer, J. F.; Slim, R. D.; Tyrer, J. D. Inorg. Chem. 1981, 20,3784.80. Gillespie, R. J.; Kent, J. P.; Sawyer, J. F. Jnorg. Chem. 1981, 20, 3799.81. Collins, M. J.; Gillespie, R. J.; Sawyer, J. F.; Schrobilgen, G. J. Acta Crystallogr. 1986,C42, 13.82. Collins, M. J.; Dènès, G.; Gillespie, R. J. Inorg. Chem. 1981, 20, 3784.83. Gillespie, R. J.; Schrobilgen, G. S.; Slim, D. R. J. Chem. Soc. Dalton 1977, 1003.84. Bartlett, N.; Wechsberg, M.; Jones, G. R.; Burbank, R. D. Inorg.Chem. 1972, 11, 1124.85. Allen, F. A.; Lerbscher, J.; Trotter, J. J. Chem. Soc. (A) 1971, 2507.86. Adams, D.C.; Birchall, T.; Faggiani, R.; Gillespie, R. J.; Vekris, J. E. Can. J. Chem. 1991,69, 2122.87. Wiliner, H.; Rettig, S. J.; Trotter, J; Aubke, F. Can. J. Chem. 1991, 69, 391.88. Wang, C.; Bodenbinder, M.; Wiliner, H; Rettig, S.; Trotter. J.; Aubke, F. Inorg.Chem.1994, 33, 779.89. Wang, C.; Wiliner, H; Bodenbinder, M.; Batchelor, R. J.; Einstein, F. W. B.; Aubke, F.Inorg.Chem., 1994, 33, 3521.90. Wang, C.; Lewis, A.; Batchelor, R. J.; Einstein, F. W. B.; Willner, H.; F. Aubke, submittedfor publication in Inorg. Chem.91. Kvick, A; Jonsson, P.-G.; Olovsson, I. Inorg.Chem. 1969, 8, 2775.92. Belin, C.; Charbonnel M.; Potier, J. J. Chem. Soc., Chem. Commun. 1981, 1036.93. Paul, R. C.; Paul, K. K.; Malhotra, K. C. J. Chem Soc., Chem. Commun. 1970, 453.94. Gillespie, R. J.; Vaidya, 0. C. J. Chem Soc., Chem. Commun. 1972, 40.23Chapter 2GENERAL EXPERIMENTAL2.1. IntroductionSince most of the compounds used in this study were moisture sensitive, extreme carehad to be taken to avoid contact with air. In addition, some starting materials and productswere corrosive and toxic. Most materials were handled inside a dry box and on glass vacuumlines. Some of the apparatus had to be designed for specific purposes. This chapter deals withthe sources and preparations of starting materials, special apparatus and general experimentaltechniques used in this study. Details of specific syntheses and product analyses will bedescribed in the appropriate chapters.2.2. Source of Chemicals Used in This StudyThe source and purity of the chemicals used in this study are listed in Table 2-1. Mostof the chemicals were used without further purification. SbF5 and HSO3F were purifiedaccording to the methods described in section Apparatus and EquipmentStandard ground glass joints were used for all connections of glass apparatus. Groundglass connections were lubricated with Halocarbon grease (Series 25-1OM) or sealed withHalocarbon wax (Series 12-00), which exhibit low reactivity towards halogen-containingcompounds. Both were obtained from the Halocarbon Products Corporation (New Jersey,USA). Occasionally, mixtures of grease and wax were used to achieve the desired consistency.In the conductometric studies, the conductivity of a solution was measured under a nitrogenatmosphere at ambient pressure. Teflon joint sleeves (Nalge Company, New York, USA) wereused to seal the ground glass joints of the conductivity cell and the liquid burette (seesection 2.5.7).24Table 2-1 Source and purity of chemicals.Chemical Source PurityHSO3F Orange County Chemicals Technical gradeOrange County, CA, USASbF5 OzarkMahoning* 99%F2 Air Products Inc. Technical gradeSO3 (Sulfan) Du Pont de Nemoms <98% (stabilized)Wilnnington, DE, USASb, 100 mesh Matheson Coleman & Bell 99.5%Au, 20 mesh Johnson Matthey Electronics 99.995%Pt, 0.5-1.2 micron Johnson Matthey Electronics 99.9%SbF3 Aldrich 99.9%Sb(0C2H5)3 Aldrich (n2° = 1.495)cx-naphthoflavone Aldrich 97%(7,8 benzoflavone)KBr Fisher A.R.KBrO3 Mallinckrodt Chemicals A.R.KC1 Matheson Coleman & Bell >99%CsC1 Matheson Coleman & Bell >99%H2PtC16 Aldrich 8 wt% aq. soin.‘205 BDH 98%CFC13 Aldrich NMR grade (>99.5%)d6-acetone Isotec Inc. (Matheson) > 99.9 atom% D* Now known as AtoChem North America.252.3.1 Vacuum LinesA Pyrex vacuum line (Figure 2-la) was employed for general purposes. The glassvacuum line had a 60 cm-long manifold with three BlO sockets, one BlO cone and one B14cone, equipped with Kontes Teflon stem stopcocks. A pressure gauge could be attached to theBlO cone to measure the pressure within the vacuum line. A safety trap cooled with liquidnitrogen was located between the manifold and a rotary oil vacuum pump to protect the pumpfrom volatile, corrosive materials.Volatile liquids were transferred in vacuo using a T-shaped bridge consisting of a Pyrextube with a BlO ground glass socket at either terminal, used to connect two glass vessels, anda. general purpose vacuum lineBlO cone, to pressure gauge Kontes Teflon stem stopcockBl4cone Bl4socketUb. Trap-to-trap distillation setup.Figure 2-1 Vacuum lines used in this study.BlO cone, to pressure gauge¶Kontes BlO socketTeflon stemstopcockpumpB14 coneBlO socketpurrpliquid N2 trap26one BlO cone equipped with a Kontes Teflon stem stopcock, through which the bridge wasattached to the vacuum line.Another vacuum line was used to carry out trap-to-trap distillation (Figure 2-ib). Theglass traps were so designed that the gas flow could bypass any one of the traps if necessary.2.3.2 Dry BoxFor the handling and storage of hygroscopic solids and liquids with low volatility, a“DRT-LAB” Model DL-001-S-G dry box (Vacuum Atmosphere Corp., Hawthorne, CA, USA)was used, filled with dry nitrogen. The removal of moisture inside the dry box wasaccomplished by circulating the nitrogen over molecular sieves located within the “DRITRAIN” Model HE-493 (Vacuum/Atmosphere Corporation, California, USA). The molecularsieves were periodically regenerated by heating in a stream of nitrogen.2.3.3 Glass VesselsOne-body reactors (Figures 2-2a and 2-2b) were used when the reaction product couldbe isolated by removal of all volatiles in vacuo. The reactors were made from either 2 mm or 3mm thick wall glass tubing (Figure 2-2a), or from approximately 25, 50 or 100 mL roundbottom flasks (Figure 2-2b), depending on the reaction conditions. The product was removedfrom the reactor by either pouring it through the valve or cutting the reactor stem off inside thedry box.Two-part reactors were used when subsequent isolation procedures were necessary andhigh pressures were not anticipated. The reactors consisted of approximately 25, 50 or 100 mLround bottom flasks (Figure 2-2c) or normal wall glass tubing (Figure 2-2d), with a B19ground glass cone fitted with a “drip lip” to trap possible grease-contaminated liquids andprevent them from mixing with the product. The corresponding adapter top had a KontesTeflon stem stopcock between a B19 socket and a BlO cone (Figure 2-2e). After completion27810 coneKontesTeflon stopcockKontesTeflon stopcockGlass fit(fine, medium orcoarse porosity)Figure 2-2 Some glassware used in this studies.KontesTeflon stopcock810 coneKontesTeflon stem stopcockof the reaction, the top adapter could be substituted by appropriate equipment such as afiltration or a distillation apparatus.A vacuum filter (Figure 2-2]) was used• for the filtration of moisture sensitivecompounds in vacuo. The design of the filter was adapted from one discussed by Shriver 1•Two Kontes Teflon stem stopcocks were used to control the pressure on either side of the glassfrit.BlO cone819 sockete819 conea b C819 socketdB14 coneB19 socketf Vacuum Filter.Stressor814 socketB14 TaperViton 0-ringBrass washerg. Ampoule Key.28Occasionally, samples were sealed in glass ampoules of various dimensions for storageor reactions of long duration. The ampoules had to be opened under vacuum. The use of anampoule key (Figure 2-2g) facilitated these operations of sealing and opening, as describedpreviously 22.4. Purification and Preparation of Some Chemicals Used in This Study2.4.1 Purification of HSO3Fand SbF5Technical grade fluorosulfuric acid, HSO3F, was purified by double-distillation atatmospheric pressure under a counter flow of dry N2, as described by Barr et a!. .Under a flow of dry nitrogen at atmospheric pressure, crude antimony pentafluoride(SbF5) was distilled using a regular distillation apparatus into a 500 mL round bottom flaskwith B19 ground glass cone. After thedistillation, the flask was immediately attachedto a vacuum line via a B19-socketfBl4-coneadapter. The N2 in the flask was promptlyremoved and SbF5 was distilled in vacuo into aspecially designed storage ampoule (Figure 2-3). The BlO cone on the top was used toconnect the storage ampoule to the vacuum lineand a BlO socket on the side arm permitsconnections to vessels from or to which SbF5was to be transferred. Air between the storageampoule and the vessels could be pumped offvia stopcock c before each transfer. Thus,contact of volatile, highly reactive SbF5 withmoist air and grease was minimized.Firgure 2-3 SbF5 storage ampoule.cap (BlO socket)810 coneKontesTeflon stemstopcock cBlO socket810 stopper292.4.2 Preparation of Bis(fluorosulfuryl) peroxide,S206FBis(fluorosulfuryl) peroxide, S206F was prepared by the direct reaction between F2and SO3, using AgF2 as the catalyst. Large quantities ofS206F could be produced using asystem adapted from the original synthesis.4’5 Over the years, a number of modifications hadbeen made to the system. The system was last used in November, 1994. The final design ofthe system and the procedure of operation are described below.The system (Figure 2-4) was comprised of three parts: a supply of gaseous reactants,the reactor and a set of traps for the collection of products. Fluorine gas could be used eitherwith or without dilution by nitrogen gas. A NaF tower was used to absorb HF which is presentin fluorine gas. Sulfur trioxide was carried by a stream of nitrogen into the flow reactor. Aheating mantle was placed under the round bottom flask to adjust the vapor pressure of SO3and to facilitate its transport by the stream of nitrogen. Four Pyrex traps were used to collectthe product. Trap A was air-cooled and used for pre-cooling the gas mixture and the detectionof unreacted polymeric SO3. The other three traps were used as product collectors. Thelocation of the outlet and inlet of the trap was intentionally reversed to allow more effectiveproduct condensation. A soda lime tower was used to treat any unreacted F2 and the byproduct FSO3.The tower reactor (Figure 2-5) was made in the Mechanical Shop in this Department,by Mr. Brin Powell and his colleagues. It was constructed of a 4” o.d. Monel-K tube fittedwith a flange and a removable top to allow the loading and removal of the catalyst. TheMonel-K tube is wrapped in two Chromel heating coils which were used to control thetemperatures of the upper and lower halves of the reactor separately. Thermocouple wireswere also wrapped inside in order to monitor the temperatures. This assembly was surroundedby Fiberfax insulating paper and Pyrex glass wool, and then encased in 0.02” thick stainlesssteel plating held tight by hose clamps. Two additional thermocouple wires in Monel wellswere inserted into the top and bottom of the reactor to measure the internal temperatures.30Figure 2-4 Schematic diagram ofthe preparation ofbis(fluorosulfuiyl) pemxide(S206F).The catalyst for the reaction was AgF2, made by fluorination of silver supported oncopper turnings. Silver was plated on copper turnings in an aqueous solution of AgNO3 andKCN. The silver-plated copper turnings were washed, dried and loaded into the reactor.Fluorination of the silver plating was carried out in a slow, undiluted stream of F2. The flowrate of F2 was controlled so that the fluorination proceeded smoothly. After completion of thefluorination, the reactor was cooled down to room temperature by flushing with dilutedfluorine, followed by purging with dry nitrogen. The inlets and outlet of the reactor were thensealed until the reactor was required for -78CC 78.Ctemp. (in dry ice bath)Product-Collection TrapsN231Thermocouple (3)WellsMonet)F2 INLET(3/8”o.d. Monet K)GAS OUTLET(318” od. Monel K)Figure 2-5 The flow reactor used in the preparation of bis(fluorosulfuryl) peroxide (S206F).6-lI4 N.C. Stainless Steel ScrewsVIRGIN TEFLON SEALCOPPER FLLNGESSILVER SOLDER(Johnson Matthey easi fib 45)S031N2INLET(3/8k o.d. Monet K)Thermocouple (1)CoUnicsUItra-Temp 3300bonded with EisenglassFi.we GbssStainlessSteel (24 ga)To IIOVVARIACMONEL-l( TUBE4 o.d. x 0.065,47” overall lengthCATALYST(AgF2 on Copper Turning)Chromel-A (2-2Oga)(Upper & Lower)Thermocouple (2)Jo 110 VVARIACTIG WELDCOPPER GAUZE1/4”MonelKThermocouple (4)32The preparation ofS206Fneeded to be monitored constantly. Fluorine fluorosulfate,FSO3, was often formed in small quantities as a by-product in the synthesis, although thereaction conditions were carefully controlled. Extreme care needed to be exercised sinceFSO3is known to be an extremely hazardous and unpredictable compound.6’7It was very important to maintain the mole ratio of the two reactants at 1:1 and thereaction temperature within the range of 1501800 C. Higher ratios ofF2/S03 than 1:1 andhigher reaction temperatures would result in large amount of hazardous by-product FSO3,while lower temperatures would lead to incomplete reaction. A low F2/S03 ratio left someunreacted SO3, which was very difficult to remove from the product. The unreacted SO3 couldbe observed condensing as a film in the first collecting trap at room temperature. The reactionof SO3 and F2 was exothermic. Thus, the reaction temperature was not only controlled by theChromel heating coils, but also depended on the flow rate of the reactants. The flow rate ofSO3 was affected by the flow rate of carrying gas (N2) and the vapor pressure of SO3. Thelatter was in turn controlled by the heating mantle. Because of the extreme difficulty of thecomplete removal of unreacted SO3 from the product, a very slightly higher, rather than lower,F2 ISO3 ratio than 1:1 was preferred.The crude product was condensed as a liquid in three collecting traps cooled to -78°Cwith dry ice. Only small amounts of the hazardous by-product, FSO3, were condensed at thistemperature. This small amounts of FSO3 dissolved in the crude product were removed byintermittently warming the product to room temperature and cooling down to -78°C. Furtherpurification was carried out using trap-to-trap distillation (Figure 2-lb) with three traps held at-10°C, -55°C and -78°C, respectively. Purified S206F was collected in the second trap at550 C. The purity was first checked conveniently by measurement of the vapor pressure andthen tested more reliably by infrared and 19F NMR spectroscopy. The purified S2O6F wasstored in sealed glass ampoules at room temperature.33The removal of the other possible by-product, SO3, was found to be much moredifficult than removal of FSO3. The trap-to-trap distillation had little effect. A treatmentinvolving liquid-liquid extraction with concentrated H2S04 in a separatory funnel was noteffective either. Extreme caution was needed for the operation; furthermore, the incompleteremoval of SO3 was often encountered. In addition, the contamination ofS206Fby waterwas inevitable and the product obtained in this manner contained a small amount ofbis(fluorosulfuryl) oxide,S205Fwhich was more difficult to remove from product than SO3.Therefore, the portion of the product mixed with SO3, together with small amounts of F2, wasreintroduced into the reactor to convert SO3 intoS2O6For, less ideally, FSO3. Even thoughFSO3 is hazardous, it is readily separable fromS206F.2.5. Instrumentation and Methods2.5.1 Elemental AnalysesElemental analyses for C, H, and S were performed by Mr. P. Borda of thisDepartment. The antimony content of the samples was analyzed in this lab. A potassiumbromate titration with a-naphthoflavone as indicator8’9was adapted. A small sample ampoulefitted with Young Teflon valve (total —5 g) and a pistol-style burette (2.000± 0.001 mL) wereemployed to improve the accuracy of sample weighing of moisture-sensitive compounds. TheKBrO3 (A.R.) was recrystallized from aqueous solution. The indicator cc-naphthoflavone wasused without purification. Blank tests and titration against A. R. grade SbCl3 indicated that thesmall amounts of impurities in the indicator had no effect on the indication of the endpoint andwould not cause any significant error.2.5.2 Melting Point DeterminationThe powdery samples were loaded into 2.0 mm old. capillary tubes in the dry box andflame sealed under nitrogen. The melting points were determined on the Thomas HooverUnimelt capillary melting point apparatus.342.5.3 Infrared SpectroscopyInfrared spectra were obtained on a Bomem MB-102 FT-JR spectrometer. For solidsamples, AgBr windows with an approximate transmission range down to about 300 cm’ wereused. Since samples were extremely hygroscopie and reactive towards most mulling agentssuch as Nujol or HCB, they were packed as thin films between two AgBr windows inside thedry box. Electrical tape was wrapped around the edges of the window plates to protect thesamples from moisture during the measurement outside the dry box. The infrared spectra wererecorded immediately after taking the sample out of the dry box to minimize any possibleexposure to moisture.For gaseous samples, a glass gas cell with a10 cm pathlength was used. Two 1 mm thick AgBrplates (Harshaw Chemicals, USA) were fitted on thegas cell using Halocarbon wax (Series 12-00,Halocarbon Products Corp., NJ, USA). The gas cellwas equipped with a cold finger, which could becooled with liquid nitrogen to facilitate thecollection of volatile materials into the cell bycondensation.2.5.4 Raman SpectroscopyRaman spectra were obtained on a Bruker FRA 106 Raman module mounted on aIFS66V FT-JR optical bench. A Nd-YAG Laser operating at wavelength of 1064 nm was usedas the excitation source. Samples were loaded into melting point capillary tubes and the tubestemporarily sealed with Halocarbon grease inside the dry box. The tubes were flame-sealedunder nitrogen as soon as they were taken out of the dry box.BI 0 coneFigure 2-6 JR gas cell.352.5.5 X-ray Diffraction StudiesSingle crystals were mounted in 0.5 mm i.d. Mark capillary tubes (supplied by CharlesSuper Co., USA) inside the dry box and temporarily sealed with Halocarbon grease. Thecapillary tubes were flame sealed immediately after being removed from the dry box. TheX-ray diffraction data were collected on a Rigaku AFC6S diffractometer using Mo-Karadiation of 0.71069 A and the structures were solved by Dr. Steven J. Rettig of thisDepartment. Details of the preparation of individual single crystals are available in theappropriate chapters.2.5.6 NMR SpectroscopyMultinuclear NMR spectra were obtained on different NMR spectrometers. Theinformation on instruments, the lock solvent and chemical shift references is listed inTable 2-2. The data for the T1 measurement, using ‘H NMR and ‘9F NMR, were acquired on aBruker AM-400, courtesy of Professor G. Herring, and a Varian XL-300 in this Department.Fluorine-19 NMR spectra were recorded by Prof. Dr. G. Hägele and Mr. Markus Heubes in theTable 2-2 Information of the NMR spectrometers.Method T1 measurement 1D & 2D ‘9F NMRNucleus 1H 19FSpectrometer BRUKER AM-400 Varian XL-300 BRUKER AM200SYFrequency 400.13 282.23 188.15(MHz)Chemical Shift residual undeuterated CFCI3(S13=0)Reference acetone(6acetone2.04)Lock solvent d6-acetone36Institut für Anorganische Chemie und StrukturchemieI, Heinrich-Heine-Universität Düsseldorf, Düsseldorf,Germany.Liquid samples were loaded into 5 mm o.d.NMR tubes by either pipetting inside the dry box ortransferring in vacuo on the vacuum line. The NMRtubes were equipped with rotationally symmetric 5.0mm Teflon stem valves (Young, London). Usually themagnet field was shimmed using an NMR tube ofsame size containingd6-acetone and the spectra wererecorded unlocked. For T1 determination and 2D-NMRexperiments, relatively long data acquisition timeswere needed. The effect of field shift on the spectracould not be ignored and data were acquired with thefield locked. A 2 mm o.d. capillary tube filled with asolution of 5%(w/w) CFCI3 ind6-acetone was flame-sealed and then inserted into the NMR tube supportedby two 0.1 mm thick Teflon spacers (Figure 2-7).CFCI3 served as a chemical shift reference for‘9F NMR and the trace amount of undeuteratedresidual in d6-acetone as a reference for ‘H-NMR.The narrowed neck facilitated flame-sealing of theNMR tubes under vacuum as symmetrically aspossible to achieve good sample spinning. The BlOcone could be attached to vacuum lines via an adapterequipped with a Kontes Teflon stem stopcock. Figure 2-7 NMR tubeBlO cone/socketadaptor—BlOconenarrowed necksealed capillary tubecontaining referenceand lock solventTeflon spacers372.5.7 Electrical Conductivity MeasurementsThe general methods and apparatus wereadapted from those reported previously.10 Thecell and a specially designed liquid additionburette used in the conductivity studies areshown in Figure 2-8. The coating of platinumblack on the electrodes was renewed after everytwo runs. Before each measurement, the cellconstant was calibrated using a 0.01000 M KC1aqueous solution as described previously.1’Theconductivity was measured with a Wayne-KerrUniversal Bridge Model B221A conductometer.The temperature was controlled by a Model STSargent Thermonitor and kept constant at agiven value within 0.005CC using a large oilbath.a. CellPlatinumFigure 2-8 Apparatus used in conductivitymeasurement.B19 groundglass jointb. BuretRotaftc GP-3Teflon ValveTo conductometerBlO coneKontesTeflon stopcock38References1. Shriver, D. F. The Manzpulation ofAir Sensitive Compounds, McGraw-Hill Book Co.: NewYork, 1969.2. Gombler, W.; Willner, H J. Phys. E. Sci. Instrum., 1987, 20, 1286.3. Barr, J.; Gillespie, R. J.; Thompson, R. C. Inorg. Chem., 1964, 3, 1149.4. Dudley, F. B.; Cady, G. H. I Am. Chem. Soc., 1957, 79, 513.5. Cady, G. H.; Shreeve, J. M. Inorg. Synth., 1963, 7, 124.6. Cady, G. H. Chem. Eng. News, 1966, 40.7. Cady, G. H. Inorg. Synth., 1968, 11, 155.8. Skoog, D. A.; West, D. M. Fundamentals of Analytical Chemistry, 3rd ed., Holt,Rinehart, & Winston: New York, 1976, p. 35.9. Morries, P. in Comprehensive Analytical Chemistry, Eds. Wilson, C. L.; Wilson, D.W.; Elsevier: New York, 1962, Vol. ic, p. 252.10. Barr, J.; Gillespie, R. J.; Thompson, R. C. Inorg. Chem., 1964, 3, 1149.11.Wu, Y. C.; Koch, W. F.; Hamer, W. J.; Kay, R. L. J. Solution Chem., 1987, 16, 985.39Chapter 3A SOLUTION STUDY OFANTIMONY PENTAFLUORIDE IN FLUOROSULFURIC ACID3.1. IntroductionDue to the intrinsic Lewis acidity of SbF5 and the limited corrosiveness of HSO3Ftowards glassware, the conjugate superacid HSO3F/ bF5 has attracted much attention insuperacid chemistry. A variety of methods, including Hammett Acidity Function (H0)determinations, ‘ electrical conductivity studies,6’7and selectivity parameter measurements,8have been used to study the HSO3F/ bF5 system. All these studies indicate that theHSO3F/ bF5system ranks among the strongest superacids.Nuclear magnetic resonance spectroscopy (NMR) is one of the best physical techniquesto obtain structural information about liquid systems. Several ‘9F NMR studies of theHSO3F/ bF5system were reported in the sixties and seventies.6’9” Because of the limitedresolution and sensitivity of the conventional NMR spectra at that time and the complicatedequilibria in the system, accurate assignment of the signals was difficult and disagreement wasfound among the reported studies. Since then the resolution and sensitivity of NMR spectrahave significantly improved. Furthermore, the introduction of Fourier transform NIvIR(FT-NMR) and subsequently the invention of various pulse-sequences have extended theconventional one-dimensional (1D) NMR into two-dimensional (2D) NMR.’2 It is nowpossible to apply these modern NMR techniques to reinvestigate the HSO3F/ bF5system toobtain more precise structural information.Presented in this chapter is an NMR study of the HSO3F/ bF5system (mole fraction ofSbF5,X,F=O.OOO999.75).Techniques include high-resolution ‘9F NMR,‘9F-’ chemicalshift correlated spectroscopy (COSY) and 19F J-resolved 2D NMR. In addition, electricalconductivity measurements over the entire Lewis acid concentration range, along with T140measurements using both 1H and ‘9F NMR are reported. The crystal structure of oxoniumundecafluoro diantimonate(V), [H30J[Sb2F1], isolated from the HSO3F/ bF5system is alsopresented.3.2. Experimental3.2.1 Preparation of NMR samplesPurified antimony pentafluoride was transferred in vacuo into a 50 mL one-bodyreactor. The amount of the antimony pentafluoride transferred was determined by differenceweighing. Inside a dry box, freshly distilled fluorosulfuric acid was pipetted into the reactor.The amount of fluorosulfuric acid was also determined by difference weighing. The mixturewas then stirred magnetically for Ca. 15 minutes. About 0.4 mL of the solution was pipettedinto an NMR tube (Figure 2-7). A sealed capillary tube containing a solution of 5% (w/w)CFC13 in CD3OCD was inserted into the NMR tube in order to provide chemical shiftreferences and a field lock. The NIVIR tube was attached to a BlO-BlO adapter fitted with aKontes Teflon stem stopcock and then taken out of the dry box. The NMR tube was evacuatedafter it was cooled to -95 —‘ -100CC in an ethanol/dry ice slurry bath. The sample was degassedby three freeze-pump-thaw cycles. The NMR tube was then flame-sealed under vacuum. AllNMR samples discussed in this chapter were prepared in this manner.3.2.2 ‘9F NMR SpectroscopyBoth 1D and 2D ‘9F NMR spectra were acquired at low temperature on a BrukerAM 200 NMR spectrometer, equipped with a Brukçr variable temperature unit B-VT 1000, byProfessor Dr. Gerhard Hãgele and Mr. Markus Heubes of the Institut für Anorganische Chemieund Strukturchemie I, Heinrich Heine Universitãt Düsseldorf, Germany. For each 1D ‘9FNMR spectrum, 64K memory size was used for data storage (TD64K) and 1024 scans wereacquired (NS=1024) for each Free Induction Decay (FID). No zero-filling was applied to theFIDs before Fourier transformation. For 19F-’9COSY NMR, a standard program,COSY.AUR, was used with the following pulse sequence:41relaxation time t1 — 90° pulse — evolution time ‘t — 45° pulse— FID [3-1]TD=2 K and NS=32 were used and 512 experiments were measured for every 2D spectrum.For 2D J-resolved NIvER, a standard program, JRES.AUR, was used and the following pulsesequence was implemented:relaxation time t1 — 90° pulse— evolution time t — 180° pulse — evolution time t — FID [3-2]TD=4 K along the F1 axis and TD=128 along the F2 axis were used and 64 experiments weremeasured for each 2D spectrum.The FIDs for 1D NMR were processed using the Bruker Win-NMR software on anIBM-compatible PC and the FIDs for 2D NMR were processed with the program UXNMRrunning on a UNIX workstation (ASPECT).3.2.3 Measurements of Spin-Lattice Relaxation Time T1The measurements of T1 using ‘H NMR were carried out on a Bruker AM 400 NMRspectrometer, courtesy of Professor G. Herring of this Department, and the measurementsusing ‘9F NMR were carried out on a Varian XL-300 NMR spectrometer in this Department.All T1 measurements were conducted at room temperature, using an Inversion-Recovery pulsesequence:relaxation time t1 — 180° pulse— evolution time t — 90° pulse — FID [3-3]where relaxation time, t1, was set to t1 > 5xT1. A standard program, INVREC.AUR, on theBruker AM-400 spectrometer and the DOT1 sub-program on the Varian XL-300 spectrometerwere used. At least 16 experiments and 32 scans for each experiment were measured for eachT1. The T1 values were calculated using 3-parameter (al, a2 and Ti) fitting to the followingequation:I\’lJMo a1 +a2 exp(-tJT1) [3-4]where t and M are, respectively, the evolution time after the 180° pulse and the relativeintensity (or peak area integral) of a particular peak measured from the corresponding42spectrum. M0 is the relative intensity (or peak area integral) of that particular peak when theevolution time t> 5 x T1. Parameters a 1 and a2 were introduced to eliminate systematic errorscaused by deviation of actual pulse widths from ideal pulse widths for the 90° and 1800 pulses.3.2.4 Conductivity Measurements of theHSO3F/MF11(S)5..(M=Sb, n=5 andM=Nb, Ta; n=4, 3) SystemsAntimony pentafluoride was purified according to the method described in Chapter 2and MF(SO3F)5(M=Nb, Ta; n=4, 3) systems were synthesized as described previously.21Conductivity measurements on theHSOFfMF(SO)5.(M=Sb, n=5 and M=Nb, Ta; n=4, 3)were carried out in a large conductivity cell (‘-‘25 mL) with a cell constant of 5.677±0.15 cm.The cell constant was calibrated after each series of measurements, using a 0.01000 M KCIaqueous solution.’3 For measurements in the low Lewis acid concentration range, freshlydistilled HSO3F was added directly into the conductivity cell from the distillation apparatus.The solutions were prepared and transferred to an addition burette (Figure 2-8, Chapter 2)inside a dry box. For the measurements in the high Lewis acid concentration range, freshlydistilled HSO3F was transferred into the addition burette, and the prepared solutions weretransferred into the conductivity cell inside the dry box. The addition burette was then fixedonto the conductivity cell before removal from the dry box. During the measurements, uponthe addition of each aliquot, the conductivity cell was shaken thoroughly, and the molefractions of SbF5 were calculated according the weight of the two components. Allconductance data were recorded at 25.00° C.3.2.5 Single Crystal X-ray Diffraction of[H30][Sb2F11Colorless crystals precipitated after several weeks from the sealed NMR samples of theHSO3F/ bF5system with XSbF5O.342. An NMR tube sealed with a sample of XSbF5O.624 wascut open inside the dry box. Crystals were carefully separated from the mixture. A colorless,prismoidal crystal with approximate size of 0.30x0.30x0.35 mm was mounted into a 0.5 mmMark capillary tube. The tube was sealed with Halogrease temporarily inside the dry box and43flame-sealed immediately after being taken out of the dry box. The X-ray diffraction data werecollected and the structure was solved by Dr. S. J. Rettig in this department. Completecrystallographic data are listed in Appendix C.3.3. Results and Discussion3.3.1 1D and 2D‘9F-’ COSY SpectroscopyThe first ‘9F NMR study of the HSO3F/ bF5system was reported by Thompson et al.6Due to the limited sensitivity and resolution of the spectra, only two partially overlapped AX4spin systems were observed from the spectrum of a 1.7 mol•kg’ solution of SbF5 in HSO3F(xsbF5 = 0.15). They were assigned to monomeric [SbF5( O3F)fand the SO3F-bridged dimer[Sb210( O3F)fand the following mechanism for their formation was proposed:SbF5 + HSO3F , H[SbF5(SO3F)] [3-5]H[SbF5(SO3F)J+ HSO3F--—H2SO3F+ [SbF5( O3F)f [3-6]2H[SbF5(SO3F)] HSO3F+[Sb2F10( O3)f [3-7]Commeyras and Olah9 extended the 19F NMR investigation of the HSO3F/ bF5system to awider SbF5/HSO3Fratio range of 0-l.4 (xFS=OO.58)and supported the earlier assignments.6In addition, they observed signals due to the monomer [SbF6f (-120 ppm) and F-bridgeddimer [Sb2F1f (-115 ppm) as well as two unassigned signals at -122 and -124 ppm. Toexplain the formation of the perfluoroantimonate(V) species, the existence of polysulfliric acidswas proposed according to:2SbF5 + 2HSO3F . H2SO3F+ [Sb2F1f + SO3 [3-8]SO3 + HSOF HS2O6F [3-9]SO3 + HS2O6F . HS3O9F [3-10]This proposal was subsequently disputed by Dean and Gillespie.’0 To decrease the viscosity ofthe system in order to improve the resolution of the spectrum, these authors used sulfuryl44chiorofluoride (SO2CIF) as a diluent for the HSO3F/ bF5system with the SbF5:HSO3Fratio at0.92:1.00 (xsbF5=O.48). Besides the signals observed previously, two A2X spin systems due tocis-[SbF4(SO3F)funits and two singlets due to trans-[SbF4(SO3F)2funits were alsoobserved. Therefore they argued that [SbF6] and [Sb2F1i] were formed more likely throughligand redistribution such as:2[SbF5(SO3F)] . [SbF4( O3F)2]+ [SbF6] [3-11]rather than through decomposition of HSO3Fas suggested in reactions [3-8], [3-9] and [3-10].More recently, Brunel, Germain and Commeyras1’ carried out ‘9F NMR studies of theHSO3F/ bF5and HSO3CF/SbF5systems, using sulfuryl difluoride (S02F) as an internalreference. They concluded that the cis-F-bridged H[SbF5(SO3F)](n=0 to 5) species were themain species in high XF5 ranges and that the SO3F-bridged dimer [Sb2F10Qi-SO3)f waspresent in low concentration only in systems with low XSbF5. This conclusion is contradictoryto previous studies,6’9”° which indicated the 1:1 and 2:1 complexes H[SbF5(SO3F)] andH[Sb2F10(j.i- O3)]were the principal species.In summary, previous ‘9F NMR studies of the HSO3F/ bF5 system differ in manyaspects: the SbF5 concentrations, the use of diluent, the spectra and the spectral interpretations.The approach in the present study was to start with the HSO3F/ bF5system with xSbF5 as lowas possible, provided that reasonable spectra can be acquired. The monomeric antimony(V)species are most likely present at low XSbF5. The mole fraction of SbF5 was gradually increasedto observe oligomerization and the changes in relative concentrations of species. To avoid anypossible interference with the system, no diluent was added into the HSO3F/ bF5system inthis study. General Features of lB ‘9F N1’vlR Spectra of the HSO3F/ bF5SystemAs an example, the ‘9F NMR spectrum of an HSO3F/ bF5system with X5O.35 isshown in Figure 3-1. The spectrum may be divided into two regions: the F(S) region45F(S) region(45—SO ppm)0Chemical Shift (ppm)Figure 3-1 ‘9F NMR Spectrum of the HSO3F/ bF5System (xSbFs=O.342)at 213 K.(&13=4O-’45 ppm), where the signals due to fluorines of SO3F groups are observed, and theF(Sb) region (&3=-80-150 ppm) where signals due to fluorines bonded to Sb(V) areobserved. In addition, there is a sharp singlet at Ca. -162 ppm, which is attributed to SiF4.Apparently, there is a trace amount of HF that reacts with Si02, the main component ofglass, to produce SiF4 according to:4HF + Si02 - 2HO + SiF4 [3-121The other product, H20, is a strong base in the system and is protonated to form the oxoniumion H3O, which is observable using ‘H NMR spectroscopy (section 3.3.2). Its salt withweakly nucleophilic [Sb2F11fas the counter anion has been isolated (section 3.3.3). The otherpossible route for the production ofH20, dehydration of HSO3Faccording to:2HSO3F . H20 +S205F [3-13]F(Sb) region(-90--- 145 ppm)CFCI350SiF4-50 -100 -15046is unlikely because the signal due to S205F at 47-48.5 ppm14”was not observed in the ‘9FNMR spectra of all samples studied in this work. Evidence for reaction [3-121 also comesfrom the observation of the slightly etched NMR tubes and capillary tubes after several weeks.The mechanism for the generation of HF is not clear. The observation of progressivelyincreasing amounts of SiF4 with increasing XSbF5 in the system suggests that the trace amountsof HF may be introduced as an impurity in SbF5. However, as discussed in the followingsections, partial solvolysis of SbF5 in HSO3Fis also a possible source of HF:SbF5 + HSO3F.. SbF4(SO3F)+ HF [3-14]SbF4(SO3F)+ HSO3F . SbF3(SOF)2+ HF [3-15]Since SiF4 is also observed by ‘9F NMR spectroscopy for neat solvent HSO3F, it is alsopossible that HF may also be formed by the self dissociation of HSO3F(K<3x107):18HSO3F. S03+HF [3-16]or introduced with HSO3Fas an impurity.Figure 3-2 illustrates the 19F NMR spectra of pure HSO3F and HSO3F/ bF5systemswith various XSbFS values in the F(S) region(6CFCI3 = 40—45 ppm). In this region, all signals aresinglets. For the solvent and solutions with low SbF5 content, intense signals due to HSO3Fdominate the region. A main peak due to F-32S0Hand a weak satellite peak due to F-34S0Hcan be observed.’6”7For example, in the 1D ‘9F NMR spectrum of fluorosulfuric acid(Figure 3-2), the very intense peak at 41.98 ppm and a weak satellite peak at 41.94 ppm areobserved. The isotope shift is 0.044 ppm, in agreement with the previous studies.’6”7 For lessintense F(S) signals, the satellite peak (F-34S0)was not observed. Long-range couplings ofthe types‘9F-S-O-Sb-’ and‘9F-S-O-Sb-O-S-’ were not observed for any samples in thisstudy. Consequently, little information about the structures of the fluoro-fluorosulfatoantimonate(V) species can be extracted from the signals in the F(S) region.4745 44 43 42XF5=O.795,T=233K41 40 45 44 41 40• 43 42chemical shift (ppm) chemical shift (ppm)Figure 3-2 Low temperature ‘9F NMR spectra (F(S) region) of the HSO3F/ bF5system.XSbFS=O (neat HSO3F), T=21 3K XSbFS=O. 194, T=21 3K42.2 42.0 418 42.2XSbFS=O.000999,T=2 13KXSbF5=O.00982,T=21 3KA•42XF5=O.O5OO, T=2 13KZJLXF5=O.O989, T=2 13KzJ45 4448In contrast, the F(Sb) region (8cI3=-80- 150 ppm) (Figure 3-3) provides a great dealof structural information. The observed splitting of the signals results from the couplingbetween non-equivalent fluorines bonded to the same antimony atom. The complex spectralfeature of this region indicates complicated equilibria of various chemical species in thesystem. The overlap of signals is sometimes so severe that an analysis based solely ontraditional 1D ‘9F NMR spectra can be ambiguous. Even with the assistance of 2D NMRmethods, the spectral analysis is occasionally inconclusive.Significant signal broadening begins to be observed in the spectrum of the HSO3F/ bF5system with XSbF5 0.500. The spectra in the F(Sb) region of the systems with XS6F5O.649 and0.795 are dominated by broad peaks. Such signal broadening precludes any detailed analysisin terms of individual species. Therefore, the assignment of signals discussed in the followingsections will focus on the F(Sb) region in the spectra of the system with low SbF5 content(0.000999 x5 0.342). For the convenience of the discussion, the following notationsystem for the assignable signals in the F(Sb) region is used. The signals in the F(Sb) regionare labeled according to their multiplicity: S for singlet, D for doublet, T for triplet, Q forquartet, q for quintet, s for sextet ..., etc. For signals of the same multiplicity, a number isattached in the order of their appearance from low field to high field.The increasing viscosity of the system, as the SbF5 content increases, may not be theonly factor responsible for the broadness of signals, because a number of relatively sharp linesare also observed in the F(Sb) region. The oligomeric structures of (SbF5)m and possiblyH[SbmF5m(SO3F)1 or H[SbmFm+j}, as well as ligand exchange, may also contribute to thebroadness of the signals. The sharp lines are probably from some relatively small complexanions. Among these sharp lines, the most intense signals labeled with T3 and T6 can beassigned to cis-[SbF4(SO3F)2f,S8 to [SbF6f, and Qi to [Sb2F1f.As reported previously,6’9”the proton exchange between the Sb(V) species and HSO3Fappears to be rapid and only averaged signals of both complex acids and their conjugate anions49S7a. XsbF5=O.000999,Temp: 213K, Enlarged(x2500)Dl T3 T5 (02) T6+ + SB(q4)M121 1 II 121S7 Inset2D2 b. XSbF5=O.O0982,Temp: 213K, Enlarged(x200)I iiInsetiT2I+ 1 121I 12J D2TI IT3121 (S4)S5T5 Q3 Q4 Q5C. XsbF5=O.O00, D2 Inset 1 Inset 2Temp: 213K, Q5 IEnlarged(xlOO)041:3:3:1S8S6 05_____________________T2 S51 T S8 q4_-90 -100 -110 -120 -130 -140Chemical Shift (ppm)Figure 3-3 ‘9F NMR spectra (F(Sb) region) of the HSO3F/ bF5system.50d. Xs5O.O989 I T6Temp 213K 02Enlarged(x20)S7 .Io . q4_S6_LiQ4rQ5____e. XsbF5O.l94 S7 D2 02Temp 213KS6 Inset 3q4Enlarged(x5) 03 1 6 4Inset 1 04 Inset 2S3 S5 D5 04 rYIii_______ _________III.lInseti lnset2f. X5=O.342, Temp 233K0118 ?88 I0304__kD5__S6 IS5S7 AT4 S4 q4NI 4j3_-90 -100 -110 -120 -130 -140Chemical Shift (ppm)Figure 3-3 ‘9F NMR spectra (F(Sb) region) of the HSO3F! bF5system (continued).51Chemical Shift (ppm)Figure 3-3 ‘9F NMR spectra (F(Sb) region) of the HSO3F/ bF5system (continued).q4qi q2d. XSbF5O.O989Temp 213KEnlargecl(x20) D2e. XSbF5O.194 D2Temp 213K S7Enlarged(x5) S6Inset 1S3 S5T4T23DInset 1I a 40 56 268 $12’SGS5 S7T4 S4T3 S3NI_ ___1V(D3 Inset304 Inset2 I_64J1LInset 2f. XsO.342, Temp 233KQiD30414P81 56 II8-90 -100 -110 -120 -130 -14052are observed in the ‘9F NMR spectra. For convenience, the anion formula are used to representboth forms in the discussion. In section, the assignment of segments (monomericSb(V) moieties), [SbF(SO3F)5..Qi-) ]-. and-f(i.i-(SO3F)SbF(SO3F)4..Qi)-]-; inthe oligomeric species are discussed. To distinguish the segments from monomeric species(both complex acids and conjugate anions), the segments are formulated as neutral fragments. Assignment of Monomeric SpeciesIn the ‘9F NMR spectra (F(Sb) region) of the HSO3F/ bF5system withXF5=O.OOO999(Figure 3-3 a), there are a number of multiplets in addition to two singlets. Apparently, severalchemical species are present in the system. The possible monomers of the type[SbF(SO3F)6..fare illustrated in Figure 3-4. In these species, antimony(V) is assumed to beoctahedrally coordinated by fluoro and fluorosulfato ligands. From the coupling patterns andrelative intensities of the signals, they can be readily assigned to some of the monomericspecies expected to be present. With the assistance of 2D ‘9F-19 COSY NMR, the analysisbecomes more straightforward and definitive. In the 2D 19F-’9 COSY spectrum (F(Sb)region) of the HSO3F/ bF5system with XSbFSO.OOO999 (Figure 3-5), the cross-peaks D1T5and T3T6 clearly indicate the correlation between doublet Dl and triplet T5, and betweentriplet T3 and triplet T6. Thus, we can unequivocally assign Dl and T5 (AX2 spin system) tomer-[SbF3(SOF)]and T3 and T6 (A2X spin system) to cis-[SbF4(SO3F)2f.The singlets in the F(Sb) region may be assigned to species containing chemicallyequivalent fluorines, namely [SbF6f, trans-[SbF4(SO3)2f,fac-[SbF3(SO),trans- andcis-[SbF2(SO3F)4fand [SbF(SO3F)5] (Figure 3-4). In previous ‘9F NIvIR studies ofHSO3F/ bF5systems with high SbF5:HSO3Fratios, Commeyras and Olah9 assigned the signalat &3=-12O ppm to [SbF6f. In the present study, however, no singlet at -120 ppm isobserved. Dean and Gillespie’0observed two singlets at -102 -104 ppm in the spectrum of asulfuryl chiorofluoride solution ofSbF5:HSO3F(0.92:1.00) at recorded at -100°C and assignedboth of them to trans-[SbF4(SO3F)2]units. Brunel et at.1’ assigned high-field singlet at53FFF(Sb): A6F.,.F—’F(Sb): A2XFF.F(S): noneF(S): A2F(Sb): A3 F(S): A3FFOSO2FFO2S OSOFSbF(Sb): A1OSO2FF(S): AX4OSO2FFIFF FF(Sb): AX4 F(S): A1F(Sb): A4 F(S): A2OSO2FOSO2FOSO2FF(Sb): AX2 F(S): AX2OSO2FFO2SFO2SO- OSOFOSO2FF(Sb): none F(S): A6Figure 3-4 Possible monomeric species of the type [SbF(SO3F)6..] (n=O—6) andtheir corresponding spin systems.F’”OSO2FF(Sb): A2 F(S): A2XFF(Sb): A2 F(S): A454—-140—--140—-130--130--120--120--110___________________________--110-100S--100ppmppm______--90--90___________.1IF—-diT3T6T6 T3T6D2q4,D4q1\-qlq4S8T3T6D1T5.:.A’o2,D4D;q4,D41•S5S6T3T3T6T2D1DITS-90-100-110Figure3-5‘9F-19COSYNMRspectrumof theHSO3F/SbF5systemwithXSbF5=O.000999.-130-4O-9010.120Figure3-6‘9F-’COSYNMRspectrumoftheHSO3F/SbF5systemwithXSbF5O.OO984.&Fc13= -115.8 ppm to [SbF6f and the low-field singlet at 6CFC -91.9 ppm to trans{SbF4( OF)2f. Following these previous assignments, the high-field sharp line S8 at-125.6 ppm is assigned to [SbF6f and the other singlet S7 at -105.0 ppm is assigned totrans-[SbF4(SO3F)f.As XSbFS increases from 0.000999 to 0.00982 (Figure 3-3b), D2 and q4 becomeconsiderably more intense in the spectrum. The relative intensities and distinct splittingpatterns in the 1D ‘9F NMR spectrum and the cross-peak D2q4 in the‘9F-’ COSY spectrum(Figure 3-6) clearly indicate that the two signals represent an AX4 spin system. This AX4 spinsystem can be assigned to monomeric [SbF5( O3F)f, which is in agreement with the previousstudies.6’94All signals assigned to monomeric species are observable in the HSO3F/ bF5system atleast up to XSbF5=O.489 except Dl and T5, which is only barely observable for XSbFS=O.OSOOand is absent in the systems with higher XSbF5. This observation suggests that the monomericmer-[SbF3(SOF)f,which has the highest SO3F content among all species observed in thisstudy, exists only at very low SbF5 concentration. It has not been observed in the previousNMR studies of HSO3F/ bF5systems with high HSO3F: bF5ratios. However, it has beenreported by Thompson et al.6 for the HSO3F/ bF4(S)and HSO3F/ bF5/50 systems. Itwas reported that, based on cryoscopic measurements, the freshly distilled HSO3F contains‘—0.0006 molekg’ of SO3,’8 which is comparable with the concentration of SbF5 in theXF5=O.OOO999 system. Therefore, the insertion reaction of SO3 with SbF5 in HSO3F6 mayhave contributed partly to the formation of species with high SO3F!F ratios.The chemical shifts and coupling constants of signals assigned to monomeric species inthe HSO3F/ bF5system with XSbF5=O.O0984 are summarized in Table 3-1. In spite of somevariations in chemical shifts for the signals with increasing XSbFS, the following generalcorrelation between the ‘9F chemical shifts and their chemical environment is observed:56Table 3-1 Assignment of monomeric species for HSO3F/ bF5system with XIJF5O.OO982Species Structure F(Sb) signal Sb(V) Mole %[SbF6] F-tEX6 systemX: -125.64 ppm(S8) <1,‘F5(OSO2F 4 system[sbF5( o3F)]FX4C A: -135.24 ppm(q4) 27FA X: -110.55 ppm(D2)JAx=100 HzOSO2F A2X systemcis-[SbF4(503F)2]FA A: -120.36 ppm(T6) 39FA X: -101.89 ppm(T3)JAx120 HzOSO2F X4 systemtrans-[SbF4(SO3F)21X: -104.95 ppm(S7) 136SO2FOSO2F AX2 systemmer-[SbF3(SOF)]Fx 0802FFA A: -109.44 ppm(T5) 4SO2F X: -96.65 ppm(D1)JAX’127 Hz(i) For the fluorine trans to a fluorosulfato group, the signal shifts to low field as cisfluorines are sequentially replaced by fluorosulfato groups in fluoro-fluorosulfatoantimonate(V).(ii) Similarly, the signal of the fluorine cis to another fluorine shifts to low field as cisfluorines are sequentially replaced by fluorosulfato groups in fluoro-fluorosulfatoantimonate(V).(iii) In the same fluoro-fluorosulfato-antimonate(V), signals due to fluorines trans to fluorineappear at lower fields than those trans to fluorosulfate.57These trends agree in general with the empirical equation established for substitutedperfluoro complex anions of the type [EFL6jm (E=Ti, W, Sn; m=2 and E=P; m=1):19t—pC+qT [3-17]In this equation, AF is the difference in chemical shift of a signal between the fully fluorinatedand partly substituted species. C and T are constants for the particular substituent and centralatom. The quantities p and q are the number of substituents cis and trans, respectively, to thefluorines whose shifts are calculated. However, attempts to quantitatively fit the data with theequation were not successful. A possible explanation is that the data collected from this systemare the averaged chemical shifts of the complex acids and the their conjugate anions.Based on integration of the signals, about 27% of the Sb(V) species is estimated to bepresent as [SbF5( O3F)], 52% as [SbF4( O3F)2f,4% as [SbF3( OF)f,and less than 1% as[SbF6f in the system with XSbF5 0.00982. This result cannot be interpreted solely by theformation of H[SbF5(SO3F)] and its conjugate anion [SbF5( O3F)f, derived from the directcombination of SbF5 with HSO3F (Equations [3-5], [3-6]) and subsequent ligandredistribution reactions:2[SbF5(SO3F)f . [SbF4(503F)2f+ [SbF6] [3-11]2[SbF4(SO3F)f. [SbF3( OF)f+ [SbF5( O3F)f [3-18]The insertion reaction of residual SO3 and SbF5 in HSO3F may contributed partly to theformation of high-SO3F-containing species in the system with XSbF5=O.000999. For thesystems with XSbFSO.OO982,such a contribution seems too small when the extremely lowconcentration of SO3 is considered. Solvolysis of SbF5 in HSO3F as shown in Equations[3-14] and [3-15] may have occurred. Otherwise, a higher concentration of [SbF6 wouldhave been anticipated.583.3.1.3 Assignment of Segments in the Oligomeric SpeciesAlthough oligomerization is expected as the SbF5 content increases, it is still surprisingthat it occurs in the system with an SbF5 concentration as low as XSbFS=O.00982. It is notedfrom the spectrum of the system with XSbF5=O.OO982 (Figure 3-3b) that three small peaks justdown field of D2 do not belong to the same multiplet. The separation from the central peak is100 Hz and 50 Hz for the lower field and higher field peaks respectively. Moreover, theintensity of the peak at higher field to the central peak is approximately twice the intensityexpected for a triplet. As illustrated in Inset 2 in Figure 3-3b, where the expected butunobserved peaks are indicated by dotted lines, it is likely that the first two peaks on the leftbelong to a triplet T5 with one peak of the multiplet buried in the intense D2, and the high-field peak is one half of a doublet D5, again, with the other half buried in D2. From thecorresponding 19F-’9COSY spectrum (Figure 3-6), D5 is correlated with a quintet qi, whichis partially overlapped with the intense q4, to form another AX4 spin system. It can beassigned to a segment of the type [SbF5-(t-SO3F)-j.In the 1D NIvfR spectrum of the HSO3F/ bF5system with xSbF5—O.OO982 (Figure 3-3b),the signals at -97.5 —‘ -101 ppm are apparently two triplets, Ti and T2, with close chemicalshifts and slightly different coupling constants. This is much clearer in the 1D ‘9F NMRspectrum (Figure 3-3c) and ‘9F J-resolved spectrum (F(Sb) region) of the HSO3F/ bF5systemwith XSbF5=O.OSOO (Figure 3-7a). In the 1D spectrum(Figure 3-3c), the signals in the region-97 -101 ppm are resolved into three triplets Ti, T2 and T3. The 19F- COSY spectrum(F(Sb) region) (Figure 3-7b) indicates Ti and T2 are correlated with Q2 and Q5, Q3 and Q4,respectively. In the 1D ‘9F NMR spectrum, the quartets Q2 and Q3 are partially overlapped toform a “sextet” with the area ratio of 1:3:4:4:3:1 in the region -115 -118.5 ppm (Inset 1,Figure 3-3c). The other two quartets, Q4 and Q5, form another “sextet” at -123.5 -127.5 ppm (Inset 2, Figure 3-3c), which is overlapped with the readily recognizablesinglet S8 at -125.8 ppm assigned to [SbF6f. Careful inspection of the frequencies and area59CTiQ2 Q3) IT6Q5 Q4IIIIIiIIIII-90-1001D5D4-110II-120tI-130.11 I1$ I I-9jII-J q4-140(ppm)—200-100—2001000 (Hz)T1Q5 T2Q4T2Q3T1Q2-10-120(ppm)--140--130--120--110--100-90a.‘9FJ-resolvedNMRspectrum.Figure3-7‘9F2DNMRspectraof theHSO3F/SbF5systemwithXSbFsO.O500.b.‘9F-’COSYNMRspectrum.T2qiq2,q4-110-130ratios of the peaks suggests that each of them results from A or M of two AMX2 spin systemsT1Q2Q5 and T2Q3Q4 respectively. These two AMX2 systems can be assigned to thesegments of the type cis-[(SO3F)SbF-Qi-) J, or of the type cis-[Q.t-SO3F)-SbF4-(.t’-)-]with two different terminal segments on each side.It is also evident from the J-resolved spectrum of the XSbF5=O.OSOO system (Figure 3-7a)that the signals at -134 -139 ppm are three overlapped quintets, qi, q2 and q4. In the‘9F-19COSY spectrum, the cross peaks D2q4, D4q2 and D5qi indicate that q4, q2 and qi arecoupled with three partially overlapped doublets D2, D4 and D5, respectively, to form threeAX4 systems. One of the AX4 systems, D2q4, has been assigned to monomeric [SbF5( O3F)].The other two may be assigned to segments of the type [SbF5(j.t-SO3F)-] with differentsegments on the other side of the bridging fluorosulfato group.In the ‘9F NIvtR spectrum of the HSO3F/ bF5system with XFS=O.OO982 (Figure 3-3b),the weak signals at -103.50 ppm are recognized as two singlets and, based on similarities inchemical shifts, are possibly the same singlets as S4, S5, and S6 observed for the xFs=O.O5OOsystem (Figure 3-3c). They can be assigned to segments of the type trans-[(SO3F)-SbF4(i-SO3F)-]. At high XSbFS, there are another three singlets, (Si, S2 and S3) at lower field(Inset 1, Figure 3-3e and Figure 3-30, which may be better assigned to segments of the typetrans-[-(ji-SOF)-SbF4-(p.’-SO) }in trimers or higher oligomeric species. The assignment ofthese singlets to monomers with high SO3F/F ratios, such as fac-[SbF3(SOF)],[SbF2( O3F)4]and [SbF(SO3F)51,is less likely because:(i) The relative intensity of S4, S5 and S6 increase as the SbF5 concentration increases,which is contrary to what is expected for the monomers with high SO3F/F ratio. As theXSbF5 increases from 0.000999 to 0.00982, in fact, the signals Di and T5 due tomer-[SbF3(SOF)fare barely observable and the relative intensities of S7 due totrans-[SbF4(SOF)2and T3T6 due to cis-[SbF4(SO3F)2]are reduced significantly;and61(ii) Singlets S4, S5 and S6 cannot be observed even in the spectrum of the HSO3F/ bF5system withX=O.OOO999 which has a high HSO3F/ bF5mole ratio. Singlets Si, S2,and S3 are observed only in the HSO3F/ bF5system with low HSO3F/ bF5mole ratios(xF5O.194).For the same reasons, assignment of these singlets to segments with a high SO3F-content, suchas trans-[(SO3F)SbF2-Q.t-SO3F)-] and [(SO3F)4SbF-(ji-SO)-], seems implausible.Two triplets, T4 and T7, emerge in the ‘9F NMR spectrum of the system withXFS = 0.0989 (the inset in Figure 3-3d) and higher. Parallel to triplets T3 and T6, which areattributed to the monomeric species cis-[SUF4(SOF)2j,T4 and T7 are also correlated to eachother as seen from the‘9F-19 COSY spectrum (Figure 3-8). They compose another A2X spinsystem which is better attributed to a segment, cis-[-(ji-SOF)-SbF-(ji-SO) ], linking twoidentical moieties.A glimpse at the signals at -109 -111 ppm in spectra of the systems with XFS=O.O989and 0.194 may give the impression that they are three overlapped doublets. However, theseparation between the two peaks of lowest intensity varies from 55 Hz for XSbF5=0.0989 to72 Hz for XSbFSO.l94. Both these separations are lower than all the coupling constants foundfor terminal fluorines in this particular system. Analysis of the intensities of the signalssuggests that they may be composed of four doublets. In the spectrum of the HSO3F/ bF5system with XSbF5O.l94,for example, these signals were analyzed by deconvolution into thefollowing four doublets: D2 (109.6 ppm, J=99Hz), D3 (110.1 ppm, J100Hz), D4 (110.3 ppm,J=lOOHz), and D5 (110.9 ppm, J=lOOHz) (Inset 2, Figure 3-3e). From the ‘9F-’ COSYspectrum (Figure 3-7 and 3-9), these doublets are correlated to the quintets qi, q2, q3, and q4at -134--’-140 ppm, respectively. Signal q3, which is correlated to the weakest of the doublets,D3, is so weak that it cannot be clearly observed in the spectrum of the XSbF5O.O989 system.As shown in Inset 3 of Figure 3-3e, only one peak remains unassignable to qi, q2, and q4 and62--140—-130—-120-110-100(PPM)-90T4T7F0Q2Q5 Q3NIQI.QiQ1q5-90•-140-130-120‘-110•-100--90 (ppm)-100F-110-120Ni-130Figure3-819F-’9FCOSYNMRspectrumoftheHSO3F/SbF5systemwithXSbFS=O.194.NIQI-140(PPM)(ppm)-90-100-110TI”-120-130-140Figure3-9‘9F-’9FCOSYNMRspectrumoftheHSO3F/SbF5systemwithXSbF5O.342therefore is assigned to q3 with the rest of q3 is buried in the intense q4. Among four AX4spin systems, D2q4 has been assigned to the monomer [SbF5( O3F)f. The other three AX4systems can be attributed to fragments of the type [SbF5-(i-SO3F)-j.A quartet, Qi, with the area ratio of 1:1:1:1 appears at —- 116.4 ppm in the spectra ofthe systems with XSbFS 0.342. It can be assigned to the eight fluorines cis to the bridgingfluorine in {Sb2F1if. As sketched in Inset 2 of Figure 3-3f, the signal is split into two lineswith a 1:1 ratio by a terminal fluorine (3=102Hz) and then further split by the bridging fluorine(3=60Hz). Only the most intense portion of the nonet Ni, due to the bridging fluorine, isbarely observable at -91.0 ppm (Inset 1, Figure 3-30. The quintet q5, due to the two terminalfluorines, falls into the qlq2q3q4 region. The correlation between Ni, Qi and q5, however, isvery clear from the corresponding‘9F-19 COSY spectrum (Figure 3-9).The assignments discussed above are summarized in Table 3-2. Some variations inchemical shifts are observed for the signals as x5 changes. The data listed in Table 3-2 weremeasured from the spectrum of the HSO3F/ bF5system with XSbFS=O.O989 except signals dueto trans-[-(t-SO3F)-SbF4-Qi’ SO) J and the dimer [Sb2F1i] which can only be clearlyobserved for HSO3F/ bF5 systems with XSbF5O.l94 and for systems with XSbF5O.342,respectively.With the assignments proposed above, it is possible to estimate the relativeconcentrations of different segments in the HSO3F/ bF5system with x0.342. The results arepresented in Table 3-3. Due to the signal overlap and possible inaccurate baseline settings overthe wide frequency range, integration errors inevitably occur to some extent. The errors aresmall for intense, narrow peaks and large for weak, broad peaks. The estimation ofconcentration of segments is not feasible for the systems with XSbF5O.489,since integration ofthe individual signals from overlapped, broadened peaks is not reliable.64Table 3-2 Assignment of ‘9F NMR signals (F(Sb) region) to segments in oligomeric fluorofluorosulfato-antimonate(V) species in the HSO3F/ bF5system (xFs = 0.0989).Structure of segment ‘9F Chemical shift (ppm) Coupling constant (liz)[SbF5Qi-SO3F)] AX4 systems:Fx A: -137.8 (q3) JA.x=100FxjoQ_ X:-109.8 (D3)FA9Fx A: -137.0 (q2) JAx=100X:-110.1 (D4)A: -135.6 (qi) JAX100X:-110.7 (D5)cis-[Q.t-SO3F)SbF4(SO)for AMX2 systems:cis-[Qi-SOF)SbFQi’-S)f A: -126.1 (Q5) JAM=1 140S02F M:-116.7 (Q2) JAx=100Fx X: -98.1 (Ti)9Fx A:-124.5 (Q4) JAM=115FA M:-118.2 (Q3)JAx=102X:_-98.3 (T2)cis-[Qi-SO3F)SbF4( ’-SO)f A2X system:F A:-121.6 (T7) JAx=124O0— X: -98.7 (T4)FFx OSO—FA FXFAtrans-[(SO3F)-SbF4(-(j.t-S) J X4 systems:F X: -102.1 (S4) Not ApplicableFx OO— X: -102.4 (S5)F X: -102.7 (S6)trans-[-(p.-SO3F) SbF4-(p’ SO)-] X4 systems:(xsbF5 0.194) X: -99.8 (Si)X: -102.0 (S2) Not ApplicableX: -102.6 (S3)dimer [SbF5-Qi-F)-SbFJ (AX4)2M system:(xsbF5 0.342) A:? JAX= 102M: -91.0 (Ni) JMX= 60X: -116.4(Qi)65Table 3-3 Relative concentrations of monomeric species and segments in oligomeric speciesin the HSO3F/ bF5system.Mole fraction of SbF5, XSbF5 0.000999 0.00982 0.0500 0.0989 0.194 0.342Species j_Signals Relative concentration, Sb(V) mole%Monomeric Species[SbF6] S8 2 < 1 < 1 < 1 < 1 < 1[SbF5( O3F)] D2q4 15 27 36 42 45 37cis-[SbF4(SOF)2] T3T6 48 39 20 12 8 7trans-[SbF(SO3F) S7 21 13 5 3 1 < 1mer-[SbF(SOF)] D1T5 14 4 2 0 0 0Segments in oligomeric Species[SbF5-Q.t-F)J Qi 0 0 0 0 0 < 1D3q3 0 0 0 3 6 15[SbF5Qi-SO3F)] D4q2 0 0 10 10 7 4D5q1 0 3 7 12 15 17cis-[SbF4Qi- O3F)2] T4T7 0 0 0 < 1 4 8cis-[SbF(SOF)Qi-SO)] or T1Q2Q5 0 6 8 4 5 2cis-[SbF4(t-SO3F)Qi’-SO)] T2Q3Q4 0 6 8 10 8 6Si 0 0 0 0 <1 <1trans-[SbF4(SO3F)Qi- O)] S2 0 0 0 0 < 1 < 1or S3 0 0 0 0 <1 <1trans-[SbFQi-SOF)(i’-)] S4 0 1 < 1 < 1 < 1 < 1S5 0 <1 2 1 <1 <1S6 0 <1 2 2 1 1663.3.1.4 Possible Oligomeric Species in the HSO3F/ bF5SystemAs the concentration of the Lewis acid SbF5 increases, it is expected that oligomericantimony(V) species should begin to appear. The relative concentration of oligomeric speciesis expected to increase while the relative concentration of monomeric antimony(V) speciesdecreases accordingly. Among the monomeric species observed, [SbF3( OF)fhas thehighest SO3F content. Therefore, the dimeric species would likely be limited to the types[Sb2F11(SO3F)] (n0, 1, 2, 3), formed by the following dimerizations by addition of SbF5 tothe monomeric species:[SbF6f+ SbF5 . [Sb2F11f [3-19][SbF5( O3F)f+ SbF5 [Sb2F10( O3)j [3-20][SbF4( OF)2f+ SbF5 [Sb9( OF)f [3-21][SbF3( OF)+ SbF5.. [Sb28( O3F) [3-22]Dimeric SO3F-containing species are unlikely to be linked by F-bridges. Studies of ternaryfluoride fluorosulfates based on vibrational spectra indicate that fluorosulfate always takesprecedence over fluoride as a bridging ligand.2024 Moreover, F-bridged dimers would havespin systems of three or more different types of fluorines, which should result in morecomplicated ‘9F NMR spectra. In this study, simple splitting patterns are observed, which canbe interpreted either in terms of monomeric species or in terms of segments linked by SO3F-bridges. Most spin systems observed consist of one or two different types of fluorines. TwoAMX2 spin systems are satisfactorily assigned to segments of the types cis-[SbF4(SO3F)-Qi-SO3F)-] or cis-[-Qi-SO3F)-SbF4-(t’-SO)-j. Coupling constants observed for mostmultiplets (98-’120 Hz) point to terminal rather than bridging fluorines. The only exceptionsare Ni and Qi, for which smaller coupling constants (60 Hz) are observed. Indeed, Ni andQi are due to the F-bridged perfluoro anion [Sb2F11f,where no S03F competes with F asthe bridging ligand. The small coupling constant (60 Hz) results from the coupling between thebridging fluorine and cis-terminal-fluorines (equatorial fluorines).67Illustrated in Figure 3-10 are all possible dimeric isomers of the types[Sb2F11..(SO3)j(n0, 1, 2, 3). The last three isomers of the type [Sb2F8( O3)fhave twoterminal fluorosulfates on the same antimony. Each of the three isomers has an AX2 spinsystem. According to equation [3-221, these isomers should have formed from the directcombination of mer-[SbF3(SOF)and SbF5. However, signals due to AX2 spin systemsother than those assigned to the monomer mer-[SbF3(SOF)fare not observed in the F(Sb)region. This suggests they may have rearranged to, other isomers. Thus, the possible dimericSb(V) species are limited to [Sb2F1if [Sb2F10( O3)f, cis- and trans-[Sb2F9(SO3)],andcis,cis-, cis, trans- and trans.trans-[SbF4(SF)-Qt-SO)-Sb)].Since the fluorine on the bridging S03F does not couple with other fluorines,information about connectivity between different segments of SO3F-bridged oligomers isunavailable. Only for the F-bridged dimer [Sb2F1if is the connectivity manifested in a uniquenonet due to the coupling of the bridging fluorine to eight equivalent terminal cis-fluorines. Inthe spectrum of the system withx5=0.342 (Figure 3-30, only a portion of the characteristicnonet Ni centered at ö13=-91.0 ppm can be observed because of its low intensity, but thecorrelated Qi at6Cl3= 116.4 ppm due to eight cis-fluorines is clearly observed.Among the four AX4 spin systems, D2q4 has been assigned to the monomer[SbF5( O3F)f. D5qi is tentatively assigned to the dimer [Sb2F10Qi-503)fand D4q2 to thesegment [SbF5-(i.t-SO3F)-] in both cis- and trans-[SbF5-Qi O3F)-Sb(SO)f. It is notedthat the appearance of the AX4 spin system D3q3 is accompanied by the emergence of theA2X spin system T4T7 and three singlets Si, S2, and S3. T4T7 can be assigned to asegment cis-[(-Qi-SO3F)-SbF4-(i.t-SO)-]linking two identical moieties at each end. Si, S2,and S3 are assigned to segments of the type trans-[-(ji-SO3F)-SbF4-Qi SO) ], which linkeither identical or different moieties at each end. The coincident appearance of these spinsystems suggests the formation of various trimeric fluoro-fluorosulfato-antimonate(V) species,e.g., cis- and trans-[SbF5-(ji SOF)-Sb4i .However, it must be pointed out68[Sb2F11] SO3F-bridged [Sb2F9( O3)]Fx Fx Fx Fx__1/Ex__I/x__j/Fx __IfxFA FM Sb FA FA OO Sb FAFF(’( F{’I F(I F(’IFx Fx Fx FxF(Sb): (AX42M F(Sb): AX4Possible SO3F-bridged dimers of the type [Sb2F9( O3)JFx OSO2F Fx FFA b”_I /x I /F___I /vOSO Sb FA FA—b—OSO Sb—OSO2FF(F/II F(I F F’(IFx FM Fx FF(Sb): AX4 and AMX2 F(Sb): AX4 and Y4Possible SO3F-bridged dimers of the type [Sb2F8( O3)]F F OSO2F OSO2F/FY I/__I /F_ ___0____ ___FSO— OSO—Sb—OSF FA b 00 Sb” FAoFF /1 0FyiF F(IF F FM FMF(Sb): Y8 F(Sb): AMX2OSO2F F Fx OSO2FFA_ ___I /F__ ___— oso Sb 0 F FA b O’0 Sb F8F(I F/I 0F I F(I F F”IFM F Fx OSO2FF(Sb): AMX2 and Y4 F(Sb): AX4 and BY2Fx OSO2F Fx F8FA b”0 I/ Fx/ 0_— OSO Sb FB FA /L OSO S( 0FF(F /1FxIF /1 0F I F IFx 0S02F Fx OSO2FF(Sb): AX4 and BY2 F(Sb): AX4 and BY2Figure 3-10 Possible dimers of the type [Sb2F1i(SO3F)1] (n = 0 3) andtheir correspondiing spin systems in F(Sb) region.69that the possibility of the existence of higher oligomeric species cannot be excluded,particularly in the systems with high SbF5/HSO3Fratios.The most intense signal of the four singlets at low field (-100 -105 ppm), S7, hasbeen assigned to the monomeric [SbF4( O3F)2f.The remaining three singlets are assigned tothe fragments of the type trans-[SbF(SF)-(p.-SO) J. S4 is tentatively assigned to trans[SbF5-(p-SO3F)-SbF4ff,S5 to cis, trans-[SbF( OF)-Q,L-SO)-Sb)],and S6to trans, trans-[SbF( OF)-Qi-SO)-Sb)].Of the two AMX2 spin systems, T2Q3Q4 and T1Q2Q5, either can be assigned to thesegment cis-[SbF4(SO3F)-(i-SOF)-] in the dimer cis-[SbFQi-SO3F)-SbF( O)] and theother to the segment cis-[SbF4(SO3F)-(i-SO) ] in the dimers cis, cis- and cis-, trans[SbF( OF)-Q.t-SO)-SbF)] or vice versa. The analysis of relative concentrations ofsegments favors the assignment of T2Q3Q4 to the dimer cis-[SbF5-(i O3F) Sb4(SO)]and T1Q2Q5 to the dimers cis, cis- and cis, trans-[SbF(SOF)-(jt- O)-Sb)]. It isentirely possible that, at high xSbFS, terminal fluorosulfato groups in the fragments of the typecis-[SbF4(SO3F)-(i-SO) ] may transform into bridging fluorosulfato groups to formfragments of the type cis-[-Qt-SO3F)-SbF4-(ji’-SO) ], which then link two non-equivalentterminal segments to form trimers or even higher oligomers. However, there is no definitiveevidence for such transformations in the ‘9F NMR spectra. The variation in chemical shifts ofthe signals may also be attributed to the shifts of the equilibria between complex acids and theirconjugate anions and to the change of the medium.Based on these assignments, it is possible to estimate the relative concentrations of theproposed oligomeric species by analysis of the relative concentration of segments. The resultsfor HSO3F/ bF5systems with XSbFS 0.342 are listed in Table 3-4. Such an estimation is notfeasible for HSO3F/ bF5systems with XSbFS 0.342 because it is impossible to obtain integralvalues for each of the overlapped, broad signals. However, it can be roughly estimated that70Table 3-4 Proposed principal species and their relative concentrations in HSO3F/ bF5system.Mole fraction of SbF5, XF5 0.000999 0.00982 0.0500 0.0989 0.194 0.342Constituent species Sb(V) mole %[SbF6] 2 < 1 < 1 < 1 < 1 < 1[SbF5( O3F)] 15 20* 36 42 45 37cis-[SbF4(SOF)2] 48 39 20 12 9 7trans-[SbF(SO3F)1 21 13 5 3 1 < 1mer-[SbF(SOF)] 14 4 2 0 0 0Total of Monomeric Species 100 76* 63 57 54 44[Sb2F11] 0 0 0 0 0 <1[SbF5-(p-SO3F)-SbF 0 3 7 12 15 17trans-[SbF-Qi OF)-Sb4(SO)] 0 3 < 1 < 1 1 1cis-[SbF5-Q.t-SO3F) Sb(SO)1 0 11 17 20 14 10trans,trans- 0 < 1 2 2 1 1[SbF4( OF)-(p.-SO)-SbF)]cis-cis-[SbF(S3F) (ji- O)-SbF)] 0 5 6 3 5 2cis-trans- 0 2 4 2 < 1 < 1[SbF4( OF)-(ii-SO)-SbF)1Total of dimeric species 0 24* 36 39 36 31cis-[SbF5Qi-SO3F)-SbF(I.L-Sr,Other trimers, and higher oligomers 0 0 0 4 10 24Total of Oligomeric Species 0 24* 36 43 46 55* From T2Q3Q4+S4=7, it is expected that ca. 7% Sb(V) species may exist as the fragment [SbF5-Qi-SOF)-] incis- and trans-[SbF10(SO)]. The signals D4q2 due to the -SbF5 moiety (an AX4 spin system) isoverlapped with D2q4 due to another AX4 spin system by coincidence.71about 67% of Sb(V) species exist as [SbF5j- moieties, 25% as cis-[SbF4]-moieties, 4.5% astrans-[SbF4} moieties and 3.5% as [Sb2F11fin the XF5=0.489 system.3.3.2 Electrical Conductivity Measurement, Spin-Lattice Relaxation Time T1 and‘H NMR Spectra of the HSO3F/ bF5SystemThe structural analysis of the HSO3F/ bF5system by ‘9F NMR spectroscopy becomesdifficult at high SbF5 concentrations because of line-broadening of the signals in the 19F NIvIRspectra. Electrical conductivity study is a useful technique for the study of conjugate superacidsystems. At low Lewis acid concentration, the electrical conductivity reflects the relativeconcentration of the acidium ion in conjugate superacids based on the same Brönsted acid.25At high Lewis acid concentration, the conductivity is more indicative of the total concentrationof ionic species rather than of the concentration of the acidium ions.Like MF(SO3F)5..(MNb, Ta; n=3, 4), SbF5 is miscible with HSO3F in any moleratio, which allows conductivity measurements over the entire Lewis acid concentration range.The conductivities ofHSO3F/MF(SO)5(MSb; n=5 and M=Nb, Ta; n=3, 4) systems areplotted against mole fraction of Lewis acid, XLA, in Figure 3-11. At low Lewis acidconcentrations (xLA<O.SO), the order of conductivity of the mixtures of Lewis acids andHSO3Fis:NbF4(SO3F)<TaF4(SO3F)<NbF3(SOF)2<<TaF3(SOF)2<<SbF5This may be viewed as an approximate order of the acid strengths of these Lewis acids. In thisseries, the first three compounds give low conductivity values of the same magnitude andbehave as very weak acids in HSO3F.TaF3(SOF)2appears to be a moderately strong Lewisacid and SbF5 is the strongest Lewis acid in HSO3F.Regardless of the different acid strengths of the Lewis acids, the curves exhibit similarshapes for all five HSO3F-based systems. At low Lewis acid concentration, the conductivity ofthe systems increases as xLA increases, reaching maxima in conductivity at XLAO. 18 —0.22.72400000000 SbF5°300 —00C.)0.9.c30>2O0-00U—e: TaF3(SOF)20 00000000 0 01OO 0 D o0 0 00 0g 0 000 00 00 0 000 o ao NbF3(SOF)2a000a ‘ 0I 00 0• TaF(SO3F) • a aa ii IAAAAAAAAA 0 oA I 0 0IO •60AAA AA A I A • 08AAA A A Nb4(SO3F) A •A101O• 0A A A 010 0I I0 0.20 0.40 0.60 0.80 1.00Mole fraction of Lewis acid, xiAFigure 3-11 Conductivity of theHSO3F/MF11(S) (M=Sb, n=5; M=Nb, Ta; n3,4).73As x increases further, conductivity decreases. Cross-overs occur in the high XLA domain,and the conductivity of the system eventually approaches the conductivity of the neat Lewisacids.It is interesting to note that the conductivity curve of the HSO3F/ bF5system is moresimilar to those of theHSO3F/MF11(S)5..(M=Nb, Ta; n=3, 4) systems rather than to that ofthe HF/SbF5 system The conductivity curve of the HF/SbF5 system has a maximum inconductivity at —6.4 mole % SbF5 (xFS=0.064).26 In the present study, all systems are basedon HSO3F and have maxima in conductivity at Ca. i 8—20 mole % (xFS = 0.1 8-’0.20).Apparently, the conductivity curves of conjugate superacids based on the same Brönsted acidare similar in shape.At low Lewis acid concentration, the principal contribution to electric conductivity ofHSO3F-based system arises from H2SO3F via the proton-jump mechanism.25 For theHSO3F/ bF5 system, oligomerization is observed at SbF5 concentrations as low asXSbFS=O.00982 (section 3.3.1). As XFS increases, the relative concentration of monomericspecies decreases while the concentration of oligomeric species increases (Table 3-4). Theefficiency of generation of the acidium ion (mole of acidium ion generated per mole of SbF5)is partially canceled by the oligomerization of Sb(V) species, resulting in a gradual leveling-off of the conductivity vs. XSbFS curve.On the other hand, a hydrogen-bonded medium is necessary for the proton jumpmechanism to occur effectively. In the HSO3F/ bF5 system, free HSO3F provides such amedium. Free HSO3Frefers to the portion of HSO3Fthat is not involved in the formation offluoro-fluorosulfato-antimonate(V) species. As xSbFS increases, the mole fraction of HSO3F(xHSO3F=l-xsbF5) decreases. Correspondingly, the amount of free HSO3F is also reduced.Therefore, as the bulk medium of the system is gradually changed from the HSO3Fto fluorofluorosulfato-antimonate(V) species, a transition of the dominant mechanism for conductancefrom the proton jump mechanism to a less efficient diffusion mechanism, or possibly an anion74transfer mechanism as well, is likely to occur. The transition results in the rapid decrease inconductivity of the system.At very high SbF5 concentration, where liquid Lewis acids are better viewed as thesolvent, the conductivity of the HSO3F/ bF5system is of the order of 10 to i0 ohm-1•cnr’,much higher than that of neat SbF5 (4.69x108 ohm’.cm’). At such a low HSO3Fconcentration, however, it is not clear if the formation of complex acids of the typeH[SbmFn(SO3F)5m.n+i1 by the interaction of HSO3F and SbF5 would be followed by theprotonation of HSO3F to form H2SO3F. When the low concentration of the possible ionicspecies and the viscous nature of the solvent (SbF5) are considered, the high conductivity ofthe system is rather striking. In addition to the diffusion mechanism, the anion-transfermechanism, facilitated by S03F and F anion-bridges, may be speculated as a possible causeof such high conductivity.Attempts to correlate the spin-lattice relaxation time T1 of HSO3F/ bF5systems withdifferent xSbF5 values to the chemical exchange process involving the proton transfermechanism or possibly the anion-transfer mechanism were unsuccessful. The spin-latticerelaxation times T1 were measured at room temperature using both ‘H and 19F NMRspectroscopy. As shown in Figure 3-12 (note different vertical axes are used), T1 decreases inboth cases as xSbF5 increases and the viscosity of the system increases. It is apparent that otherrelaxation mechanisms, such as the dipole-dipole mechanism, dominate the relaxation process.Two signals can be observed in room temperature ‘H NMR spectra of the HSO3F/ bF5system with XSbF5 0.00982. The plot of chemical shift vs. XFS is shown in Figure 3-13. Thehigh field signal is attributed to HSO3F/H2SOand the low field signal is attributed to theoxonium ion, H30t Olah and Commeyras9reported that öTMS(H3Oj is a function of both themole ratio of HSO3F/ bF5and the water concentration. More recently, however, Rimmelineta!.27 suggested that öTMS(H30) could be used as an internal reference for 1H NMR insuperacid media since variation in chemical shift of the oxonium ion (H30j is within7520 .516-- • T1 measured by 19F NMR12 • Timeasuredby 1HNMR 3. . z— 8. •2. I—4..•1.• . .0— I Io 0.20 0.40 0.60 0.80 1.00Mole Fracon of SbF5 ,xsbF5Figure 3-12 Spin-lattice relaxation time T1 of the HSO3F/ bF5system.1211 H2SO3F/HSO• • .H3OJH27.6. I I I I I I I I0 0.20 0.40 0.60 0.80 1.00Mole Fraction of SbF5 ,XSbF5Figure 3-13 Dependence of ‘H NMR chemical shifts on SbF5-concentration in the HSO3F/ bF5system.760.07 ppm up to 50 mole% (xsbFS=O.S). In this study, it was found that the signal due to theoxonium ion shifts to high field as XSbFS increases at least up to XSbF5O.S. The variation of thechemical shift is as large as 1.1 ppm from XSbF5=O.OS to XSbF5=O.SO. Therefore &TMS(H30), ormore appropriately &Ms(H3O/H2),is dependent on the SbF5 concentration and hence on theacidity of the superacid medium used. Thus, the. oxonium ion is unsuitable as an internalreference in superacid systems.3.3.3 Crystal Structure of[H30][[Sb2F11From the NMR samples with a high SbF5 content (xsbF5O.342), crystalline materialprecipitated after several weeks. This material was characterized as [H30][Sb2F11Jbyvibrational spectroscopy and single crystal X-ray diffraction. The crystallization of[H30][Sb2F1] can only be observed for systems of high SbF5 content, although the H3O ioncan also be detected by ‘H NMR spectroscopy for HSO3F/ bF5 systems of low SbF5concentrations, as discussed in Section 3.2.2. The formation of [H30][Sb2F11 is notsurprising. Many stable oxonium salts containing monomeric complex anions have beenobtained from H2O-MF-HF systems.2832 The anion [Sb2F11f has been used to isolateunusual inorganic and organic cations. When the complexity of the HSO3F/ bF5system isconsidered, however, it is somewhat surprising that other anions, such as cis-[[SbF4(SOF)2fas detected by 19F NMR spectroscopy (Figure 3-3h), do not precipitate out of the solution. Theisolation of[H30][Sb211suggests that its solubility is lower than the other possible oxoniumsalts in the HSO3F/ bF5system.The crystals of[H30][Sb2F1] are orthorhombic, with a 12.744(2) A, b39.371(2) A,e11.407(3) A, and belong to the space group Pbca. As shown in Figure 3-14, the unit cellcontains 24 molecules, of which three molecules are unique. Perspective views of thestructures of the three unique molecules are illustrated in Figures 3-15a, b and c. The positionsof the H atoms were located from a Fourier difference map and idealized with d(H-O)=0.89 Aand the isotropic displacement parameters U=l.2mbomded. Of the oxonium salts previously77reported, the structures of [H30][SbF6,3’4[H30][BF4],5 and [H30][TiF56 have beendetermined by single crystal X-ray diffraction. In these oxonium salts, the O-H• •F hydrogenbond lengths range from 2.522(6) to 2.558(5) A for [H301[TiF5],6 2.577 to 2.609 A for[H30][BF4],5 and 2.622(12) to 2.713(10) A for [H0][SbF6.34 A much wider range ofhydrogen bond (O-H•F) distances from 2.553(8)A to 2.976(9)A was found for[H30][Sb2F11Jin this study.Many crystal structures of compounds containing [Sb2F1i] have been reported.37 In[H3F2][Sb1 the [Sb2F1] ion has been reported to have an eclipsed configuration and alinear, symmetrical F-bridge, similar to the structure model shown in Figure 3-lSd. A similarstructure with a slight deviation from linearity (ZSb-Fb-Sb173±6.4°) has been reported for[Sb2F11fin {BrF4][Sb2F11 but the structural determination is not reliable (R=0.14). In allother cases, the Sb-Fb-Sb bridges are symmetrical within error limits but the bridge bondangles deviate significantly from linearity. With the weaker and longer bridging Sb-Fb bond,the octahedral coordination environment of antimony is distorted. Four equatorial fluorinesFigure 3-14 Stereoscopic view of the unit cell of[H30][Sb2F1j.78H2Figure3-15Molecularstructuresof [H30][Sb2F1ii(a,b,c;33%probabilitythermalellipsoidsareshown,bondlengthsinA)andamodelofthe[Sb2F1]ionwithD4hsymmetry(d).H3aHiF4F2H4*H7*F7bF14H2H2H4*F5F20F6FlOHiH3F17FeqF3 F4 F5 F6 FeqF8 F9 FlOFl1LFiSbiFeq85.9(2)85.8(3)83.5(2)86.4(3)LFlSb2Feq85.0(2)86.2(2y85.5(2)°84.4(3)FeqF14F15F16F17SbiFeq1.821(6)1.803(6)1.820(5)1.801(6)Sb2Feq1.839(6)1.833(6)1.827(6)1.808(6)FeqSb1-F294.6(3)94.1(3)96.0(3)93.6(3)°LFeqSb2$792.5(3)94.9(3)97.0(3)94.6(3)LF12Sb3Feq84.8(2).85.6(2)85.7(2)86.4(2)LFI2Sb4Feq85.3(2)85.2(2)85.8(2)84.4(2)Sb3Feq1.830(6)1.809(5)1.811(5)1.811(6)Sb4Feq1.799(6)1.829(6)1.842(6)1.829(6)ZFeqSb3Fi394.7(3)°93.6(2)94.6(2)94.3(3)LFeqSb4F1893.8(3)95.8(3)95.2(3)94.7(3)°FeqF19F20F21F22CH9)H8/180Feq,,.FeqSbSbFaxFax/I/1FeqIFeqIFeqFeqFigure3-15Molecularstructuresof[H30][Sb2F1ii(a,b,C;33%probabilitythermalellipsoids areshown,bondlengthsinA)andamodel ofthe[Sb2F11JionwithD4hsymmetry(d) (continued).F25H2*F30F31dH3*H1*00 CF33F27F32H3*FeqH5*FeqFeqLF23Sb5FeqSb5Feq£FeqSb5F24F2586.0(3)1.824(7)95.4(3)F2684.2(2)1.799(6)95.1(3)F2786.6(2)1.802(6)92.O(3)F2886.2(2)1.810(6)94.5(3)FeqLF23Sb6FeqSb6FeqFeqSb6F29F3084.9(2)1.846(6)93.7(3)F3185.6(2)1.835(6)95.9(3)F3286.5(3)1.785(7)95.0(3)F3385.5(2)°1.83 8(6)92.9(3)[Sb2F11]withD4hsymmetry(Feq) are approximately in the same plane but they are displaced towards the bridge fluorine(ZFeqSbFb850and away from the antimony (ZFeqSbF95°). The two planes are ina gauche configuration except in [BrF4][Sb2F1ii and[H32][Sb11. Some terminal fluorinesare involved in inter-ionic interactions, which may result in some small variations in Sb-F bondlengths and angles.The structures of [Sb2F1if in all three unique molecules of [H30][Sb2F1] havesymmetrical (Figure 3-15c), or approximately symmetrical (Figure 3-15a and b), Sb-Fb-Sbbridging bonds. The bridging bond angles ZSb-F-Sb145.9(2)°, 148.39(3)’, 149.4(3)’ deviatefrom linearity significantly. The most acute one (145.9(2)’) is also the smallest bridging bondangle among all [Sb2F11fsalts reported. The axial Sb-F bond lengths are close to or slightlylonger than the equatorial SbFeq bond lengths. In the structure shown in Figure 3-15c, bothSb-F bonds are longer than the SbFeq bonds, probably due to the formation of hydrogenbonds between Fax and the oxonium ions. Although [Sb2F1f ions in both [H30][Sb2F11and[H3F2][Sb1143are involved in hydrogen bonding, the influence of hydrogen bonds on theirstructures is different. In [H3F2][Sb11,45the axial fluorines of [Sb2F11 form hydrogenbonds with [H3F2] and the cations are linked by the anions to form infinite chains. In[H30][Sb2F11],both axial and equatorial fluorines are involved in hydrogen bonding, resultingin complicated structures.The infrared spectrum of [H30][Sb2F1J is shown in Figure 3-16, together with theassignment of the vibrational bands. The vibrational bands due to H3O ion are assignedaccording to C3,,, symmetry. Attempts to obtain a good-quality Raman spectrum wereunsuccessful due to decomposition of the sample during the acquisition of the spectrum.3.4. ConclusionWith high resolution ‘9F 1D NMR and 2D NMR (COSY and J-resolved), more thantwelve fluoro-fluorosulfato-antimonate(V) species have been identified and the relativeconcentrations of these species have been estimated for the HSO3F/ bF5system with SbF581a)C.)CuE(I)Cu660692Vibrationsdue to [Sb2F11]I I I I I I I I I I I I II I4000 3300 2600 1900 1200 500(cm-1)Figure 3-16 FT-infrared spectrum of[H30j[Sb2F1ii.concentrations ranging from XF5 = 0.000999 to XSbFS = 0.342. The 1:1 and 1:2 complexesbetween HSO3F and SbF5, [SbF( O3F)f and [Sb210( O3F)f, are the principal species inthe system. Other constituent species including monomers, ([SbF6f, [SbF4( O3F)2f,[SbF3( OF)f as well as dimers ([Sb2F1iF [Sb29( O3)1,and [Sb8( OF)fl, arepresent in the system. Trimers of the type[SbF5-Qi-SOF)-SbF4(j..t- exist in thesystem with XSbFSO.O989,All the oligomeric fluoro-fluorosulfato-antimonate(V) species are better describedas SO3F-bridged rather than F-bridged except undecafluoro-diantimonate(V). Theoligomerization can be observed at very dilute SbF5 concentrations. The relativeconcentrations of oligomeric species and the degree of oligomerization increase as the SbF5content increases. This is also reflected in the conductivity vs. XSbF5 curve of the HSO3F/ bF5system. At low SbF5 concentration, the increase in conductivity with increasing XF5 arises2362 2338(C02)3271 3139vs VdH3O8911613 H3OH3O82from efficient generation of the acidium ion, which is the main contributor to the conductivity.As the SbF5 content increases, oligomerization leads to a leveling-off in the conductivity of thesystem, which reaches a maximum at XFSO. I 8—O.20. The rapid decrease in conductivity asXSbFS increases further may be attributed to the change of the bulk medium from HSO3F tooligomeric Sb(V) species.In addition to ligand redistribution reactions, solvolysis of SbF5 in HSO3F appears tobe occurring in the system. The reaction of HF with Si02 produces H20, which is a strongbase in the conjugate superacid and therefore reduces the acidity of the system. This maypresent a drawback in the application of conjugate superacids based on binary fluorides andHSO3Fin academic research, where the reaction vessels are made of glass. The oxonium ion(H3O) can be detected by ‘H NMR spectroscopy in the system with low SbF5 content as well.The ‘H NMR chemical shift due to H3O is dependent on the SbF5 concentration and H3Ocannot be used as an internal reference in the superacid media. An oxonium salt,[H30][Sb2F1ii, has been isolated from the HSO3F/ bF5system with high SbF5 content andthe structure of[H30][Sb2F11has been determined by single crystal X-ray diffraction.83References1. Gillespie, R. J.; Peel, P. E. J. Amer. Chem. Soc. 1973, 95, 5173.2. Sommer, J.; Canivet, P.; Schwartz S.; Rimmelin, P. J. Amer. Chem. Soc. 1978, 100, 2576.3. Sommer, 3.; Canivet, P.; Schwartz S.; Rimmelin, P. Nouv. J. Chim. 1981, 5, 45.4. Gold, V.; Laali, K.; Morris, K. P.; Zdunek, L. Z. J. Chem. Soc., Chem. Commun. 1981,859.5. Gold, V.; Laali, K.; Morris, K. P.; Zdunek, L. Z. .1. Chem. Soc., Perkin Trans. II 1985,859.6. Thompson, R. C.; Barr, J.; Gillespie, R. 3.; Mime 3. B.; Rothenbury, R. A. Inorg. Chem.1965, 4, 1641.7. Gillespie, R. J.; Ouchi, K.; Pez, G. P. Inorg. Chem. 1969, 8, 63.8. Kramer, G. M. I Org. Chem. 1975, 40, 298; 1975, 40, 302.9. Commeyras, A.; Olah, G. A. J. Amer. Chem. Soc. 1969, 91, 2929.10. Dean, P. A. W.; Gillespie, R. 3. J. Amer. Chem. Soc. 1969, 91, 7264.11. Brunel, D.; Germain, A.; Commeyras, A. Nouv. J. Chim. 1978, 2, 275.12. Sanders 3. K. M; Hunter, B. K. Modern NMR Spectroscopy: A Guide for Chemists, 2nded.; Oxford Univ. Press: Oxford, 1993.13. Wu, Y. C.; Koch, W. F.; Hamer, W. J.; Kay, R. L. I Solution Chem. 1987, 16, 985.14. Gillespie, R. J.; Robinson, E. A. Can. J. Chem. 1962, 40, 675.15. Lustig, M. Inorg. Chem. 1965, 4, 1828.16. Stewart, R. A.; Fujiwara, S.; Aubke, F. J. Chem. Phys. 1968, 49, 965.17. Gillespie, R. J.; Quail, J. W. J. Chem. Phys. 1963, 39, 2555.18. Gillespie, R. 3.; Mime, 3. B.; Thompson, R. C.; Inorg. Chem. 1966, 5, 468.19. Chevrier, P. 3.; Brownstein, S J. Inorg. Nuci. Chem. 1980, 42, 1397.20. Gillespie R. 3.; Rothenbury, R. A. Can. J. Chem 1964, 42, 416.8421. Wilson, W.W.; Aubke, F. J. Fluorine Chem. 1979, 13, 431.22. Imoto, H.; Aubke, F. J. Fluorine Chem. 1980, 15, 59.23. Zhang, D.; Aubke, F. J. Fluorine Chem. 1992, 58, 81.24. Willner, H.; Mistry, F.; Aubke, F.; J. Fluorine Chem., 1992, 59, 333.25. Thompson, R. C. in Inorganic Sulfur Chemistry; Ed. Nickless, G.; Elsevier: Amsterdam,1968; Chapter 19, p 587.26. Gillespie, R. J.; Moss, K. C. J. Chem. Soc. (A) 1966, 1170.27. Rimmelin, P.; Schwartz, S.; Sommer, J. J. Org. Mag. Res. 1981, 16, 160.28. Christe, K. 0.; Schack, C. J.; Wilson, R. D. Inorg. Chem. 1975, 14, 2224.29. Masson, J. P.; Desmoulin, J. P.; Charpin, P.; Bougon, R. Inorg. Chem. 1976, 15, 2529.30. Christe, K. 0.; Wilson, W. W.; Schack, C. J. J. Fluorine Chem. 1978, 11, 71.31. Selig, H.; Sunder, W. A.; Disalvo, F. A.; Falconer, W. E. J. Fluorine Chem. 1978, 11, 39.32. Selig, H.; Sunder, W. A.; Schilling, F. C.; Falconer, W. E. J. Fluorine Chem. 1978, 11,629.33. Christe, K. 0.; Charpin, P.; Soulie, E.; Bougon, R.; Fawcett, J.; Russell, D. R. Inorg.Chem. 1984, 23, 3756.34. Larson, E. M.; Abney, K. D.; Larson, A. C.; Eller, P. G. Acta Crystallgr. 1991, B47, 206.35. Moota, D.; Steffen, M. Z. Anorg. Allg. Chem. 1981, 482, 193.36. Cohen, S.; Selig, H. J. Fluorine Chem. 1982, 20, 349.37. Davies, C. G.; Gillespie, R. J.; Ireland, P. R.; Sowa, J. M. Can. J. Chem. 1974, 52, 2048.38. Mckee, D. E.; Peacock, R. D.; Russell, D. R. J. Chem. Soc., Chem. Commun. 1969, 62.39. Mckee, D. E.; Adams, C. J.; Zalkin, A.; Bartlett, N. I Chem. Soc.,Chem.. Commun. 1973, 26.40. Lind, M. D.; Christe, K. 0. Inorg. Chem. 1972, 11, 608.41. Edwards, A. J.; Taylor, P. J. Chem. Soc., Dalton Trans. 1975, 2174.8542. Nabdana, W. A. S.; Passmore, J.; White, P. S.; Wong, C. Inorg. Chem. 1990, 29, 3529.43. Edwards, A. J.; Taylor, P. J. Chem. Soc., Dalton Trans. 1973, 2150.44. Miller, H. B.; Baird, H. W.; Bramlett, C. L.; Templeton, W. K. J. Chem. Soc., Chem.Commun. 1972, 262.45. Mootz, D.; Bartmann K. Angew. Chem., mt. Ed. Engi. 1988, 27(3), 391.46. Bodenbinder, M, Balzer-Jöllenbeck, G.; Wiliner, H.; Batchelor, R. J.; Einstein, F. W. B.;Wang, C.; Aubke, F., submitted to J. Amer. Chem. Soc. for publication.86Chapter 4THE SYNTHESES AND CRYSTAL AND MOLECULAR STRUCTURESOF ANTIMONY(III) FLUORIDE FLUOROSULFATES[SbF(SO3F..11x (n=1, 2, 3)4.1. IntroductionAntimony exhibits oxidation states +3 and +5 in most of its compounds. In addition,there are also some species where the formal oxidation state of antimony appears to be lowerthan +3. The known examples include several gaseous, molecular fragments of the type SbO,SbX (X = H, F, Cl, Br, or I), and SbH2, which are usually generated by flash photolysis ofSbH3 or the corresponding trihalides and are studied using kinetic spectroscopy.1 In thesespecies antimony is univalent or divalent. There appears to be little doubt regarding thetransient existence of these molecular fragments in the gas phase.In the condensed phase the situation is much less clear. Several claims have been madein short, preliminary publications.24 They date back over 20 years and point to the possibleexistence of low valence antimony species. The polyatomic cations Sb82 and Sb42 wereclaimed to exist in strong protonic acids or in solid compounds such asSb4(SO3F)2.’ Thesereports were subsequently discredited.4 The reported UV-visible spectra could be attributed tothe polyatomic sulfur cations Sg2 and S42, seemingly formed by the reduction of HSO3F orH2S04by antimony. In the same communication, the formation and isolation of a white solidof the composition Sb(SO3F) was claimed,4 but neither spectroscopic characterization noranalytical details on this intriguing material were reported in the literature.The oxidation state +1 for antimony was also suggested for Sb[AsF6], formed byoxidation of antimony with AsF5 in liquid SO2.5 The anion [A5F6J was identified by‘9F NMR and infrared spectroscopy, and a magnetic susceptibility measurement at 18°C was87interpreted in terms of very weak temperature-dependent paramagnetism due to a cluster cationof the type [SbnJ.5The formation of a white, fluorosulfate-containing solid in the initial stages of theoxidation of elemental antimony by S206F prompted a reinvestigation of the reportedformation of Sb(SO3F) in the reaction of antimony with HSO3F. However, antimony(I)fluorosulfate was not obtained in spite of numerous attempts. All the white solids from varioussynthetic approaches were found to contain only antimony in the +3 oxidation state instead ofthe unusual +1 oxidation state. Three antimony(III) fluoride fluorosulfates were isolated fromthese solids. Their syntheses, vibrational spectra and molecular structures are presented in thischapter.4.2. Experimental4.2.1 Syntheses of [SbF2( O3F) Reaction of Antimony with HSO3FThe compound [SbF2(SO3F)]x was obtained in the reaction of antimony and HSO3F.In a typical preparation, 0.5428 g (4.46 mmol) of antimony powder and 6.7796 g (67.7 mmol)of HSO3Fwere added to a one-body reactor fitted with a Kontes Teflon-stem stopcock. Thereaction proceeded smoothly at room temperature. Sulfur dioxide was detected by infraredspectroscopy as a reaction product in the gas phase above the reaction mixture. As the reactionproceeded, formation of a yellow solid was also observed. The mixture was stirred for about 2days until all antimony powder was consumed and a mixture of yellow and white solid materialhad formed. After removal of the yellow solid (S8) by hot filtration in vacuo at 50°C, 0.7064 gof white powder was obtained from the filtrate after cooling and filtration, followed by dryingthe product in vacuo. The isolated yield was 61%. The antimony content (Sb%) of the productwas analyzed to be 47.5% by a standard bromate titration,78 compared with the calculatedvalue of 47.04% for SbF2(SO3F). The white powder did not melt or decompose below 250°C.884.2.1.2 Solvolysis ofSbF2(0CH5)in an Excess of HSO3FThe precursor SbF2(0C2H5)was first prepared by a stoichiometric redistributionreaction of SbF3 and Sb(OC2H5)3(2:1 mole ratio) in acetonitrile as reported previously.6 In atypical preparation, 2.010 g (10.34 mmol) of SbF3 and 1.393 g (5.42 mmol) of Sb(OC2H5)3were combined in a 50-mL two-part reactor in a dry box. About 25 mL of previously driedCH3N was added to the reactor by vacuum transfer. The mixture was then stirred for 1 day atroom temperature. A fine white powder was obtained after filtration. The powder was dried invacuo at room temperature for one day to remove the solvent (CH3CN) completely. A 2.01 gof white powder was obtained (isolated yield 84%). The antimony content (Sb%) wasanalyzed to be 60.4%, compared with the calculated value of 59.5% for SbF2(OCH5).[SbF2( O3F)jwas obtained by subsequent solvolysis ofSbF2(0CH5)in HSO3F. In atypical preparation, 0.5 g of SbF2(0CH5)was added to a 50-mL reactor inside the dry box.Then -5 mL of HSO3Fwas transferred to the reactor in vacuo. The mixture was stirred first atroom temperature overnight and then at 50°C until all the solid had dissolved to form acolorless solution. Removal of all volatiles in vacuo produced [SbF2( O3F)].To prepare single crystals suitable for X-ray diffraction analysis, the HSO3F solutionwas allowed to cool very slowly to room temperature. Colorless crystals were obtained.4.2.2 Synthesis of jSbF(SO3F)2]Antimony (0.1515 g, 1.244 mmol) was added to a reactor fitted with a Kontes Teflon-stem stopcock. Then 11.2 g (56.50 mmol) ofS206Fwas transferred to the reactor in vacuo.The reaction was allowed to proceed slowly at room temperature for 2 weeks. After removalof all volatiles (pumping for 48 hours), 0.497 g of a gray sticky mass was obtained. (This graysticky material appears to be a mixture of a white solid, a black metal powder and a colorless,viscous liquid.) Excess HSO3F was then added in vacuo to the residue. After one day, themetal powder disappeared and solid yellow granules were observed, together with a whitepowder. When the mixture was heated to 50°C, the white solid dissolved in HSO3F, but the89yellow material (S8) remained suspended in solution. The yellow solid was then removed byfiltration in vacuo at 50°C. A white precipitate appeared as the filtrate was cooled down toroom temperature.To prepare a crystal suitable for single-crystal X-ray diffraction analysis, the filtratewas warmed up again to 50°C in vacuo to dissolve the white solid, resulting in a colorlesssolution. The solution was then allowed to cool down very slowly to room temperature. Acolorless, long rhombic crystal was obtained and fragments of this crystal were used for thestructure determination.4.2.3 Synthesis of [Sb(SO3F)1Antimony tris(fluorosulfate) was synthesized by the controlled oxidation of antimonywithS206Fin HSO3F. In a typical preparation, 0.49 11 g (4.034 mmol) of antimony powderand 15.51 g (155 mmol) of HSO3F were added to a two-part reactor inside the dry box. Tosuppress the reaction between antimony and HSO3F the reactor was taken out of the dry boxand cooled down to liquid-nitrogen temperature immediately after the HSO3F was added.S206F2was transferred in vacuo from a preweighed vessel. The weight of the container wasmonitored during the transfer. In this manner slightly more than the stoichiometric amount ofS206F(1.5667 g, 7.9 13 mmol) was added to give an Sb to S206Fmole ratio of 1:1.96. Thereaction proceeded smoothly at room temperature. The mixture was stirred for about two daysuntil all the metal powder was consumed and a white solid resulted. A hot filtration was performed in vacuo at 50°C to ensure that all yellow solid was separated from the whiteprecipitate. After the hot filtration, the filtrate solution was cooled to room temperature toallow the product to precipitate again. A white powder (0.93 g 2.22 mmol) was collected byfiltration in vacuo, which corresponds to an isolated yield of 55%. The Sb% was analyzed tobe 28.7% for the product, compared with the calculated value of 29.06% for Sb(SO3F).[Sb(SO3F)]melted with decomposition at 153°C.904.2.4 X-Ray Crystallographic Analyses of [SbF2( O3F)1, [SbF(SO3F)21, andLSb(SO3F)1All three compounds are hygroscopic. The single crystals were mounted into 0.5 mmMark capillary tube made of Lindemann glass inside a dry box. The capillary tubes weretemporarily sealed with Halocarbon grease inside the dry box and flame-sealed immediatelyafter being removed from the dry box. X-Ray diffraction analyses were carried out byDr. Steven J. Rettig of this Department. Complete lists of crystallographic data, atomiccoordinates, equivalent isotropic thermal parameters, bond lengths and angles, anisotropicdisplacement parameters, torsion angles, and non-bonded contacts for [Sb(SO3F)],[SbF(SO3F)2],and [SbF2( O3F)]are listed in Appendix D.4.3. Results and Discussion4.3.1 SynthesisThe first report on the reaction of antimony with HSO3F was published in 1967. Itwas reported that antimony dissolves in boiling HSO3F (b.p. l62.7C) to give a colorlesssolution; but the product was neither isolated nor characterized and the nature of the dissolutionprocess was not elucidated.Paul et. al.2 reported later that the oxidation of antimony in HSO3Fresulted in a clearsolution. In the presence of potassium persulfate or bis(fluorosulfuryl) peroxide, however, itformed a blue solution which rapidly changed to green and finally to yellow. Based on theresemblance of the UV-vis spectra of these solutions to those of Se42 and Te42, the existenceof unusual polyatomic antimony cations, Sb42 and Sb82, in these colored solutions wassuggested. In addition, a solid compound was isolated and formulated as Sb4(SO3F)2based onelemental analysis; but no details or other spectroscopic characterizations were reported.Subsequently, Gillespie and Vaidya repeated the reaction and observed a similarcolored solution.4 However, the absorption bands in the UV-vis spectra were attributed to thepolyatomic sulfur cations S1ó2,S62,S42, and SO2. Based on the results from other physical91characterization methods including ESR, they doubted the existence of the polyatomicantimony cations. Instead, a white solid with the composition of Sb(SO3F) was claimed to beisolated from the solution. But, again, neither analytical data nor spectroscopiccharacterizations were reported on this unusual compound with antimony in the +1 oxidationstate.The observations in this study confirm the conclusions by Gillespie and Vaidya4 thatdissolution of elemental antimony at 25°C in doubly distilled HSO3Fresults in an oxidation ofantimony, which leads, depending on the reactants’ ratio, either to a colorless solution or awhite precipitate, as reported earlier.4’6 However, in addition to SO2 as reduced byproduct,identified from the IR spectrum of the gas phase above reaction mixture, a yellow, solidmaterial is formed, which was subsequently found to be elemental sulfur, S8. Addition ofS206F2to the reaction mixture at this point produces blue-green solutions, with the color dueto the polysulfur cations.4”°The yellow solid can be separated from the mixture by hot filtration. Heating themixture to 50°C results in dissolution of the white solid only. Filtration of the hot solutiongives colorless filtrate, from which a white, crystalline material forms upon cooling to roomtemperature. Slow, controlled cooling of the hot filtrate to room temperature yields colorless,prismoidal crystals, suitable for single crystal X-ray diffraction. The composition of thecrystalline material isolated by filtration at this point was determined to be SbF2(SO3F) byelemental analysis. This was confirmed by single crystal X-ray analysis.However, a white solid obtained by removal of the solvent from the filtrate in vacuowas found to have an approximate composition of SbFn(SO3F)(3) with n varying in the rangeof 1.6-1.8 for different preparations. This suggests a product mixture with fluoridefluorosulfates of antimony(III) —SbF2(SO3F), SbF(SO3F)2 Sb(SO3F)3, and even SbF3.The oxidation state of antimony in all products is identified to be +3 instead of +1 asclaimed before. This identification is based on the following observations:92(i) Hydrolysis of the solutions and any of the solid products, including those obtained byremoval of solvent in vacuo before hot filtration, in 4 M aqueous HCI gives colorless, clearsolutions. Gas evolution or formation of elemental antimony is not observed. Thisbehavior is not consistent with the presence of cyclic or polyhedral clusters of thecomposition {Sb]11 as suggested for Sb[AsF6j.5(ii) In these acidic, aqueous solutions, the antimony content is reliably and reproduciblydetermined by a standard bromate titration.7’ The analytical data for antimony (Sb%) ofall the samples agree with the oxidation of antimony from Sb(III) to Sb(V) with KBrO3but not from Sb(I) to Sb(V).(iii) The final argument is provided by the crystal structures of the principal components of themixture. From the reaction of antimony and HSO3F, following product separation by hotfiltration and recrystallization from HSO3F, [SbF2( O3F)] was obtained (yield 61%) asdescribed in the experimental section. The amount of product obtained in this manner waslarge enough for a structure determination, the recording of vibrational spectra, andmicroanalysis for antimony. The analytical results for crystalline [SbF2( O3F)lx areconsistent with the composition established by single crystal X-ray diffraction.In a previous report,4 the unusual oxidation state +1 was deduced from the compositionof the solid isolated from reaction of antimony and HSO3F. No separation of elemental sulfurfrom the product was mentioned although the gradual precipitation of sulfur from solution wasnoticed by the authors. Furthermore, it was stated in the publication that “elemental sulfur wasalso obtained as a sublimate when the solid Sb(SO3F) was heated at 6OC under vacuum for 2-3 days”,4 It is therefore conceivable that the reported solid “Sb(SO3F)” might be a mixture ofsulfur and antimony (III) fluoride fluorosulfates. The high sulfur content of the mixture mayhave formed the base for the formulation of Sb(SO3F). The existence of antimony with theunusual oxidation state +1 in this particular system is questionable unless new evidencesurfaces.93Initial attempts to synthesize Sb(SO3F)5by oxidation of antimony powder with excessS206Fled to mixed products. The reaction at room temperature eventually yields gray, stickygranules, which is obviously an inseparable mixture of the starting material (antimony powder)and at least two products, a white solid and a colorless, viscous liquid. When HSO3F isintroduced after the removal of S206F, the black metal powder disappears due to theoxidation of antimony metal by HSO3F andlor residual S206F2, giving rise to a whiteprecipitate and a yellow solid. IfS206Fis added into the mixture, the white solid disappears,apparently due to the further oxidation of Sb(III) to Sb(V) derivatives. After the treatmentwith HSO3Fwithout addition ofS206Fand separation from S3 by hot filtration, a colorless,prismoidal crystal was obtained, later determined to be antimony(III) fluoride bis(fluorosulfate), [SbF(SO3F)2],by a single crystal diffraction study.Although the molecular structure of [SbF(SO3F)2Jwas determined (vide infra), noother characterizations, such as elemental analysis and vibrational spectroscopy, wereaccomplished for this compound. The crystal obtained was used for X-ray diffraction.Repeated attempts to prepare this compound in larger quantity have been unsuccessful. Theproducts so produced contain primarily [Sb(SO3F)], based on their vibrational spectra(section 4.3.3) and elemental analysis. The successful preparation of [SbF2( O3F)] by thesolvolysis of SbF2(0CH5)6 in HSO3F suggests an alternate route for the synthesis ofantimony(III) fluoride fluorosulfates. The starting material is prepared as reported previously 6by a ligand redistribution reaction between SbF3 and Sb(OC2H5)3in acetonitrile and isolatedas a solid precipitate. The other redistribution product, SbF(0C2H5)is reportedly soluble inCH3CN and obtainable after removal of the solvent in vacuo.6 However, the observationspoint to an equilibrium in CH3N solution:2SbF(0CH5). SbF2(OCH5)+ Sb(OC2H5)3 [4-1]Because of this ligand redistribution, SbF(0C2H5)which would be a suitable precursor forsynthesis of SbF(SO3F)2,may not be obtained as a pure compound by the removal of solvent,94even though satisfactory analytical data for S. C, and H are obtained. The preliminary studysuggests that it is possible to obtain SbF(0C2H5)2at low temperature (0 —. 5C) by using alarge excess of Sb(0C2H5)3(which is miscible with CH3N) to shift the above equilibrium tothe left side (equation [4-1]). The effort to isolate SbF(0C2H5)as a precursor for[SbF(SO3F)2]was discontinued, because solvolysis of Sb(OC2H5)3 in HSO3F gave[SbF( OF)], but not [Sb(SO3F)]or [SbF(SO3F)2j,as the main product. It was realizedthat HSO3Fmay act as fluorinating agent, which has a fair number of precedents.’1 Anotherpossible alternate route to [SbF(SO3F)2],the reaction of [Sb(SO3F)]and [SbF3}in HSO3Fat a 2:1 mole ratio, leads to a mixture of products.The previously reported oxidation of antimony by bis(fluorosulfuryl) peroxide inHSO3F“ was used to prepare [Sb(SO3F)]according to:2Sb + 3S206F HSO3F- 2Sb(SO3F) [4-2]A small excess ofS206F was employed to ensure complete and efficient oxidation. AnySb(V) species so produced remains in solution and solid [Sb(SO3F)3]xis isolated as a whitesolid by filtration. Recrystallization from HSO3F affords single crystals suitable for amolecular structure determination.Besides the solvolysis of Sb(0C2H5)3in HSO3Fmentioned above, another attempt toobtain antimony(III) tris(fluorosulfate), [Sb(SO3F)J, by solvolysis of SbCI3 in HSO3Faccording to:SbCl3 + 3HSOF HSO3F [Sb(SO3F)1+ 3HCI [4-3]was unsuccessful. Although a small amount of HC1 was detected by gas-phase IR, the reactionwas so slow that unreacted SbCI3 recrystallized in HSO3F.It is interesting to note that in addition to [Sb(SO3F)jx, the two fluoride fluorosulfatesof antimony(III), [SbF2( O3F)] and [SbF(SO3F)2],are well-defined crystalline compounds95with polymeric molecular structures. In contrast, the corresponding antimony(V) fluoridefluorosulfates of the composition SbFn(SO3F)5(n 3 to 4.5) are viscous liquids.12-’4 TheseSb(V) fluoride fluorosulfates are better viewed as nonstoichiometric phases,’4 where thecomposition depends on the synthetic route chosen, the reactant ratio, and the subsequenttreatment of the products (cooling, heating, or distillation) due to rapid F vs. SO3F-exchangeand the facile conversion of -SO3F to -F and vice versa by S03-elimination or S03-insertionreactions.In summary, the attempts to obtain and to characterize Sb(SO3F) from the reaction ofHSO3Fwith Sb have not been successful. However, it is still possible that univalent antimonyis present in Sb[AsF6} as claimed.5 A more extensive characterization of this material isdesirable.4.3.2 Molecular Structures of [SbF2( O3F)1, [SbF(SO3F)2],and LSb(SO3F)3]x4.3.2.1 Description of the Molecular StructuresAs seen from the crystallographic data listed in Appendix C, the structures of threefluorosulfato-derivatives of the type [SbF11( O3F)3..n]x (n = 0, 1, or 2) belong to three differentcrystal systems and are determined to very high precision (R = 0.026 for [SbF2(SO3F)]x andR = 0.027 for the other two). As a common feature, all three compounds have polymericstructures linked by both fluoro- and fluorosulfato-groups. But coordination numbers andgeometries around Sb(III) differ for all three, as illustrated in Figure 4-1, Figure 4-2 andFigure 4-3. As in [SbF3] 15 (Figure 4-4), fluoride functions as an asymmetrically bridgingligand in [SbF2(SO3F)]x and [SbF(SO3F)2]; however, both the short and the long Sb-F bonddistances are different. All three oxygen atoms of each fluorosulfato group are involved in theinteractions with antimony atoms, while the fluorine atom of each fluorosulfate group is farbeyond the distance of the sum of the van der Waals radii of antimony and fluorine. Therefore,the fluorosulfato group may be regarded as an asymmetrically bridging, 0-tridentate ligand inall three fluorosulfato-derivatives.9609* 05*SbI * 08*2.550(3)03 06*SI$2642(3)12.112(3) 07Fl°’02 F2 04F3Sb 1*09 /54ç/Sb 1*Figure 4-1 Perspective view of the complete coordination environment of Sb(ffl) in[Sb(S03F)J(33% probability thermal ellipsoids are shown, bond lengths in A).Sb 1 *06*05*02*03 3.055(2)SbiF30305 Sbl*Si 04Sbi* 02 S206F1*F2Figure 4-2 Perspective view of the complete coordination environment of Sb(flI) in[SbF(S03F)](33% probability thermal ellipsoids are shown, bond lengths in A).97Sb 1*Figure 4-3 Perspective view of the complete coordination environment of Sb(III) in[SbF2( 0F)](33% probability thermal ellipsoids are shown, bond lengths in A).Figure 4-4 Perspective view of the complete coordination environment of Sb(III) in [SbF3](re-drawn from reference 15, 50% probability thermal ellipsoids are lengths in A).Sb 1*01 01* F2F3 *Sb 1 *03 Fl 0203*F3F2*Sb 1*F( 1*)F( 1)F(2*) F(2)F(1*)F(1*)98Solid state structures of main group derivatives with the central atoms below theirhighest oxidation states are generally very complex. In addition to covalent bonds, longintermolecular contacts with the distances close to or slightly shorter than the sum of the vander Waals radii, are observed. These intermolecular contacts are often termed secondarybonds,16 As rough guidelines for the following discussion, the sum of the covalent single-bondradii for Sb-O and Sb-F are 2.07 and 2.05 A,’7 while the sum of the van der Waals radii are3.57 and 3.52 A for Sb-O and Sb-F respectively.’8 These calculated distances are veryapproximate, because the radius for Sb usually pertains to pentavalent antimony. As can beseen from Figures 4-1, 4-2 and 4-3, the bond distances between antimony and coordinatingatoms in the three molecular structures range from 2.052 to 3.055 A for Sb-O bonds and 1.893to 3.098 A for Sb-F bonds. The short Sb-F bond distances (-‘1.9 A) are shorter and the shortSb-O bond distances (-‘ 2.1 A) are longer than the sums of the corresponding covalent radii.In addition to covalent bonds’7 and secondary bonds’6, which have been firmlyestablished and documented in subvalent main-group compounds, there are bonds with lengthsbetween the covalent bond length and distance of secondary contacts. To describe these bonds,the term intermediate bonds will be used. This concept is best illustrated by the structure of[SbF(SO3F)2]. Each SO3F group forms one covalent Sb-O bond. The range of Sb-O distances, as seen in Figure 4-2, is 2.113(1) to 2.13 1(1) A, slightly longer than the sum of thecovalent radii. The second oxygen of each fluorosulfate group forms an intermediate bond toantimony with Sb-O bond distances of 2.475(2) and 2.566(1) A. Finally the third oxygen atomof each SO3F group is involved in secondary bonding with Sb-O distances of 2.995(2) and3.055(2) A.Because of the effectively asymmetric bridging of all ligands, the resulting coordinationgeometries are irregular polyhedra. No two Sb-O or Sb-F bond distances or bond angles areidentical. Therefore, the descriptions of the coordination polyhedra can only be approximate.In this series of antimony(III) fluoride fluorosulfates, [SbF(SO3F)..J(n =0, 1, 2), different99coordination geometries are encountered in all three cases. Short Sb-F and Sb-O bonds and theangles define the primary coordination geometries. The complete coordination environmentaround antimony in [Sb(SO3F)]is shown in Figure 4-1. The primary coordination sphereconsists of three short Sb-O bonds (-2. 1 A), arranged in the form of a trigonal pyramid withantimony at the top. Three secondary Sb-O contacts (—3.0 A) form the other trigonal pyramidon the other side, completing a distorted trigonal prism. This is different from the distortedtrigonal ant4rism (or distorted octahedron) formed by three short Sb-F bonds and three longSb-F contacts in SbF3 (Figure 4-4) although they belong to same point group. Three faces ofthe distorted trigonal prism are capped by another three oxygen atoms, which form a trigonal,approximately planar coordination environment for antimony with d(Sb-O) -p2.6 A. The three-dimensional polymer is of relatively high symmetry, and a 6-fold screw axis is discernible(Figure 4-5a).As seen from Figure 4-2, the primary coordination geometry of [SbF(SO3F)2]x consistsof two short Sb-O bonds (-‘ 2.1 A) and one short Sb-F (1.893(1)A) bond, arranged in the formof a trigonal pyramid. The local symmetry is reduced from C3, in [Sb(SO3F)]to C in[SbF(SO3F)2]with a mirror plane containing the Sb-F bond and dividing the two Sb-O bonds.When two oxygen atoms from two neighboring SO3F groups coordinate to the antimony fromeach side of the mirror plane, the local symmetry (approximately C5) is retained if the smalldifference in the bond lengths (2.475(2)A and 2.566(1) A) is neglected. However, if threeadditional long contacts are included, the local symmetry is lowered to C1, although two ofthem (O(6)* and F(1)*) are almost in the mirror plane. The Sb-F”Sb bridge in [SbF(SO3F)2]is highly asymmetric (1.893(1) and 3.098(2) A), more so than in SbF3,15 and deviates fromlinearity with Sb-Frn “Sb =1 57.35(7)°. The primary coordination pyramids are cross-linked bytwo intermediate Sb-O bonds, expanding into layers along a and b axes. The two-dimensionallayers are then further linked by the secondary contacts to form three-dimensional polymers(Figure 4-Sb).1004Ca.[Sb(SO3F)Jo .+ab.[SbF(SO3F)2JAoI+QC.[SbF2( O3F)]j+cFigure 4-5 Stereoscopic view of the unit cells of [SbF2(SO3F)]x, SbF(SO3F)2],and [Sb(SO3F)J.101While the primary coordination geometry is best described as a trigonal pyramid for[SbF3],15 [SbF(SO3F)2],and [Sb(SO3F)],a different geometry is observed for the primarycoordination sphere of [SbF2(SO3F)]x. In this molecular structure, as shown in Figure 4-3, atriangular SbF2 moiety with an acute bond angle (88.4(2)°) is expanded by another triangularSb02 moiety with an obtuse bond angle (157.1(2)°) into a very distorted square pyramid(—‘C2). While the difference between the two short Sb-F bonds is small (Sb-F = 1.896(3) and1.927(3) A), the difference between the two Sb-O bonds is rather large (Sb-O 2.204(3) and2.342(3) A). Both Sb-O bonds are slightly longer than those short covalent bonds but areconsiderably shorter than the intermediate bonds in [SbF(SO3F)2]and [Sb(SO3F)].Therefore they are viewed as covalent bonds rather than intermediate bonds, although there isno definite boundary between the primary, intermediate and secondary bonds. Thus, as anapproximation, the fluorosulfato group might be viewed as a symmetrically bidentate bridgingligand if the only long Sb-O contact is ignored. With shorter covalent bonds and longersecondary contacts, both fluoro bridges in [SbF2(SO3F)]x are more asymmetrical than in[SbF3]x)5 Formation of the fluoro bridges expands the primary coordination polyhedron into adistorted octahedron with 0 in trans positions and links polymeric SbF2(p.-SO3F)chains into acorrugated, three-dimensional polymer (Figure 4-5c). This crosslinking may also be reinforcedby a secondary bond (2.946(3) A) between Sb and the third oxygen of the fluorosulfate group. Structural Comparison of the Series LSbFn(SO3F)nIxThe structure of [SbF3]x was determined to a lesser degree of accuracy in 1970.15With the successful structure determination of the other three members of the series[SbFn(SO3F)3..nlx (n = 0, 1, 2, 3) in this work, it now becomes possible to discuss the bondingand stereo-chemistry of antimony(III) fluoro-fluorosulfato-derivatives in detail.In the three fluoro-derivatives, all fluorines are involved in both covalent bonding andsecondary contacts in an asymmetrically bridging fashion. The ratios of the secondary contactdistance to covalent bond length range from 1.36 in SbF3, 1.39 and 1.49 in [SbF2( O3F)], to1021.64 in [SbF(S03F)2],reflecting the stronger Sb-F covalent bonds and weaker secondarycontacts as the fluorosulfato groups are sequentially replaced by fluorines in the series.In the three fluorosulfato-derivatives, all Sb-0 bond distances, and the correspondingS-0 bond lengths as well, differ from one another. The S-0 bonds retain some multiple bondcharacter even where 0 is covalently bonded to antimony. As the Sb-0 distances vary fromprimary (— 2.1 ±0.1 A), intermediate (- 2.6 ±0.1 A), to secondary bonds (—‘ 3.0 ±0.1 A), theS-0 distances vary in an inverse manner over a considerably narrower range. This inverserelationship between S-0 bond distances and 0-Sb bonding interactions is apparent inFigure 4-6. The range of S-0 bond distances (1.407(3)-i .496(3) A) extends to both sides of S0 bond distances in ionic SO3P (1.43 A in KSO3F 19 and 1.436(2), 1.437(2) and 1.458(2) A inCsSO3F20). The S-F distances (—1.539 A) vary within error limits and are shorter than those3.2+3.OS 2.& +9Cl, ++- +++2.4+2.2 ++I I I I I I I I I1.40 1.42 1.44 1.46 1.48 1.50S-O bond length (A)Figure 4-6 Correlation between S-0 bond and Sb-0 bond distances.103of ionic SO3F (1 .57A in KSO3F 19 and 1 .569(2)A in CsSO3F20). Fluorine attached to sulfuris not involved in coordination to antimony, which is also apparent from its relatively largethermal ellipsoids in Figures 4-1, 4-2, and 4-3. Only for [SbF2( O3F)] is a very slightlyshorter S-F bond distance (1.529(3) A) noted; however, its primary coordination sphere andthe coordination mode of the SO3F group are different from [SbF(SO3F)21x and [Sb(SO3F)3]x.Coordination modes of the SO3F groups are different in three fluorosulfato derivatives.In [SbF2( O3F)], the coordination mode of the SO3F group approximate to bidentate if theweak Sb• •‘O secondary contact is neglected. In [SbF(SOF)2], both SO3F groups areasymmetrical tridentate with one short covalent, one intermediate bond and one long secondarycontact, but the corresponding S-O distances differ from each other for two SO3F group. In[Sb(SO3F)3]x, only one of the three fluorosulfato groups coordinates to antimony with oneshort covalent, one intermediate and one long secondary contact. The second fluorosulfateforms one covalent and two intermediate bonds while the third one forms one covalent and twosecondary contacts with the central antimony. There is no apparent rationale for thecoordination modes of fluorosulfato groups among the three fluorosulfato-derivatives. Ingeneral, all the SO3F groups function as asymmetrical, O-tridentate bridging ligands.As bidentate bridging fluorides are sequentially replaced by 0-tridentate fluorosulfatein the series [SbF(SO3F)3.jx (n 0, 1, 2 or 3), the overall coordination geometry changesfrom a distorted octahedron for [SbF3]x’5 (Figure 4-4), a pentagonal bipyramid for[SbF2( O3F)] (Figure 4-3), a face-capped pentagonal bipyramid for [SbF(SO3F)2](Figure 4-2), to a tri-capped distorted trigonal prism for [Sb(SO3F)](Figure 4-1). Thecoordination number changes from 6 for [SbF3]to 7 for [SbF2( OF)], 8 for [SbF(SO3F)z}and 9 for [Sb(SO3F)3]x, corresponding to the maximum donor sites available on the ligands.The stereochemistry of antimony(III) halides and some related derivatives, includingSbF3, is discussed in terms of the VSEPR model in reviews.21’2 The primary coordinationgeometries of all antimony(III) trihalides are of the AX3E type, where A, X, and E represent104central atom, ligand and lone-pair, respectively. The lone pair causes the bond angles to beless than the ideal tetrahedral angle (109.5°) in every case. The ZX-A-X bond angles decreasein the order of Sb13, SbBr3, SbC13 and SbF3. The decreased ZX-A-X bond angles can berationalized by the increased electronegativity of the ligands. The primary coordinationgeometries in [SbF(SO3F)2]and [Sb(SO3F)jare trigonal pyramidal (Table 4-1); but thebond angles are more acute than that in SbF3. This cannot be interpreted in terms ofelectronegativity since the electronegativity of the SQ3F group is lower than that of fluorine.23Table 4-1 Bond distances and angles for the primary coordination geometries of the[SbFn(SO3F)..nJx (n 3, 2, 1, or 0) compounds. *Species and Geometry Point Group Bond Distances (A) Bond Angles (°)[SbF3]** Sb-F(1) 1.94(2) F(1)-Sb-F(1) 88.9(1.5)trigonal pyramid Sb-F(2) 1.90(2)SbF( 1 )F( 1 )F(2)[SbF2( O3F)] Sb-F(2) 1.896(3) F(2)-Sb-F(3) 88.4(2)distorted square Sb-F(3) 1.927(3) F(2)-Sb-O(3) 83.2(1)pyramid -C2vSb-O(2) 2.342(3) F(3)-Sb-O(2) 75.6(1)SbF(2)O(2)F(3)O(3)Sb-O(3) 2.204(3) O(2)-Sb-O(3) 57.1(2)[SbF(SO3F)2] Sb-F( 1) 1.893(1) F( 1 )-Sb-O( 1) 85.66(6)trigonal pyramid Sb-O(4) 2.13 1(1) F(1)-Sb-O(4) 86.43(7)CsSbO(1)O(4)F(1) Sb-O(1) 2.113(1) O(1)-Sb-O(4) 75.71(6)[Sb(SO3F)] Sb-O(4) 2.129(3) O(1)-Sb-O(4) 82.1(1)trigonal pyramid Sb-O(1) 2.112(3) O(1)-Sb-O(7) 82.3(1)C3SbO( 1)0(4)0(7) Sb-0(7) 2.057(3) 0(4)-Sb-0(7) 82.5(1)* The reference systems for atoms are adopted from Figures 4-1, 4-2, 4-3, and 4-4.** From reference 15.105The primary coordination geometry of SbF2(SO3F) may be better described as theAX2X’E type, where X and X’ represent different ligands. It is derived from a trigonalbipyramid with F in equatorial and 0 in axial positions. Again the lone pair would have to bevery demanding sterically to produce an LF-Sb-F bond angle of 88.4(2)°, about 31.6° moreacute than a normal equatorial angle (12O). It appears that not only the intra-molecularcovalent bonds but also the inter-molecular interactions, which give rise to secondary andintermediate bonds, determine the geometry of the primary coordination sphere. The veryacute angles of the primary geometries are produced by repulsion between the electron densityin primary, intermediate, and secondary bonds, rather than by an imaginary lone electron pairthat would necessarily occupy a enormous volume of space, judged from the very acute bondangles observed. The VSEPR concept provides a useful guide for understanding moleculargeometries of main group compounds in gas phase or in liquid state. Due to the structuralcomplexity involving different levels of bonding (covalent, secondary and intermediate bonds)in the [SbF2( O3F)], [SbF(SO3F)2]and [Sb(SO3F)],the molecular geometries cannot bereadily described using the VSEPR model.The bond valence method24 has been used to interpret bond lengths and to determinethe valence of atoms in crystals. The valence of an atom i is the sum of the bond valences ofall the bonds formed between atom i and j atoms around atom i:V = Vij [4-4]The bond valence of a bond between atoms i and j can be calculated from the bond length d1using a empirical expression:v = exp[(R1-d1)Ib] [4-5]where b is commonly taken to be a universal constant equal to 0.37 A.25 refers to the bondvalence parameter and, in formal sense, is the length of a single bond. Using the “universal”value of b=0.37A and R(Sb-F)=1.883 A and R(Sb-0)=1.973 A,26 the valence of antimony iscalculated as 3.09 for [SbF3], 3.022 for [SbF2( O3F)], 3.003 for both [SbF(SO3F)2Jand1062.926 for [Sb(SO3F)31x when the secondary bonds and intermediate bonds are counted (seeAppendix B). Without consideration of secondary bonds and intermediate bonds, the valenceof antimony is calculated to be 2.67 for [SbF3], 2.758 for [SbF2( O3F)], 2.311 for[SbF(SO3F)2Jand 2.151 for [Sb(SO3F)](see Appendix B). The secondary bonds play animportant role in the crystal structures of these compounds. However, the bond valencemethod cannot predict or explain the coordination geometry around antimony. Comparison to Other Related StructuresVery few solid fluoride fluorosulfates of low valent main-group elements are known.Of these, only FXe(SO3)27 has structurally characterized. Its molecular structure is ratherstraightforward. The coordination environment of xenon is linear, the SO3F group ismonodentate and the S-O bond distances for the non-coordinated 0-atoms are equivalentwithin error limits.More relevant to the present study is the recently reported molecular structure of abinary fluorosulfate Sn(SO3F)2,8 which has also been determined to a high degree ofaccuracy. As in [SbF2(S03F)], the primary coordination geometry is described in VSEPRterms as AX4E, and inclusion of two longer Sn-O contacts also results in a distorted octahedralenvironment, similar to the one shown here in Figure 4-3. There is also comparablecomplexity, and as in [SbF(SO3F)2]x, the two SO3F groups are structurally different.The short primary Sn-O bond distances are somewhat longer than Sb-0 bonds in[SbF2( 03F)J and fall between 2.338(3) and 2.427(3) A. Consequently, the range of thecorresponding S-0 distances is narrower (1.404-1.457 A) and it appears also that F, bonded tosulfur, may be involved in a long-range interaction with tin. The narrow range of Sn-0primary bonds makes it more appropriate to use the VSEPR concept.2’ For [SbF2(SO3F)]x thisrange is between 1.896(3) (Sb-F) and 2.342(3) A (Sb-0) and consequently all polyhedra aregreatly distorted.107Differences in element-oxygen primary bond distances between Sn(SO3F)226 and[SbF2( O3F)] may in part be due to differences in the radii for Sn(II) and Sb(III),respectively, and in part due to slightly reduced steric crowding in the primary coordinationsphere for [SbF2(SO3F)]x where only two, rather than four, fluorosulfate groups are involvedin coordination to the central atom.A formal similarity exists between [Sb(SO3F)]and [Au(SO3F)]2,9the only othermetal tris(fluorosulfate) for which the molecular structure is known. However, as the formulaindicates, gold tris(fluorosulfate) is dimeric, the coordination environment is approximatelysquare planar, commensurate with a d8 electron configuration, and monodentate and bidentatefluorosulfate groups are encountered. Only a few weak and long intermolecular contactsbetween gold and oxygen are noted that contribute to an elongated, strongly distortedoctahedral coordination environment for gold. All these features are in strong contrast toobservations made here for [Sb(SO3F)].Finally two sulfato derivatives of Sb(III), formulated as Sb2Oy2SO3 30 andSb2O3SO,1 were structurally characterized in the 1970s. The structure of Sb2O32S wassaid to consist of pairs of SO4 tetrahedra and SbO3 trigonal pyramids sharing corners to form“blocks that are then linked by van der Waals bonds between oxygen atoms”.3’The primarycoordination sphere of SbOy3SO3 may be better described as a distorted square pyramid,similar to that in [SbF2( O3F)J. For both sulfato-derivatives, Sb-O distances were found tobe similar to the ones observed in this work. Primary Sb-O bond distances as short as 2.028 Awere observed. ‘While secondary or intermediate interactions were not discussed forSb2O3SO,’long-range Sb-O contacts of —‘2.7-2.87 A were noted for Sb2O3SO by theauthors.32 It appears that the structural complexity encountered in the fluoride fluorosulfates ofantimony(III) extends also to the sulfate derivatives,3132 but this may not have been recognizedpreviously.1084.3.3 Vibrational Spectra of [SbF2( O3F)Jand [SbF(SO3F)2jMany fluoride fluorosulfates of main-group elements and transition metals in theirhighest oxidation states have been reported, including solid polymeric materials such asGeF2(SO3F) ,3 SnF2(SO3F)4 and liquid, oligomeric fluoride fluorosulfates of the typeMFn(SO3F)5..n (M=Sb, n=3 41213, 4513; M=Nb, n=3, 4, 4.5 and M=Ta, n=3, 435). For allthese compounds, octahedral coordination of the central atom, the presence of symmetricallybridging fluorosulfate groups, and terminal monodentate fluoro ligands have been suggested.Evidence has come mainly from vibrational spectra and, in the case of SnF2(SO3F)2, from‘19Sn Mössbauer spectra.34 In a few molecular structures, e.g. those of (CH)2Sn(SOF),36[A’u(SO3F)]2,°and more recently [Pd2(L-CO)2](SO3F)2,37the presence of symmetricallybridging SO3F groups has lent additional support for the structural conclusions regarding thesemain-group element fluoride fluorosulfates.It is therefore interesting to record vibrational spectra of [SbF2(SO3F)]x and[SbF(SO3F)2]as well as of [Sb(SO3F)]to note the effect of decidedly asymmetricallybridging fluorosulfate groups on the vibrational bands, in particular the SO3F-stretching region(1450-800 cm’). With the symmetry of the fluorosulfato groups reduced below C3v, nineftindamentals, including four stretching modes for each SO3F group, are expected. In addition,a comparison of the vibrational spectra for the two pairs [SbF2(SO3F)]x and SbF4(SO3F)’2”or[SbF(SO3F)2]and SbF3(SOF)2’ is of interest. The emphasis here is again on the SO3Fstretching vibrations and on the identification and assignment of the Sb-F vibrations, whereasymmetric fluoride bridges are found for the Sb(III) compounds.The vibrational spectra of [SbF2( O3F)j are shown in Figure 4-7, together withapproximate descriptions for the vibrational bands. The FT-JR spectrum was obtained fromthe same crystalline material used in the X-ray diffraction study. An identical spectrum wasobtained from a sample formed by solvolysis of SbF2(0CH5)in HSO3F. The solvolysis ofSb(OC2H5)3in HSO3F also produces [SbF2( O3F)] and a Raman spectrum of the productwas obtained. The Raman spectrum is of poorer quality than the JR spectrum and109Raman Shift i5 (cm-1)Figure 4-7 Vibrational spectra of [SbF2( O3F)] with approximate descriptions of thevibrational bands.FT-Infrared1246 1204v(S-O) v(S-O)1060v(S-O)416(SO3)518565 Vas(SbF2)819 Vsym(SbF2)G)ECl)1500v(S-F) 6(S03)10201260FT-Ram an780Frequency i5 (cm-1)300540Vsym(SbF2)562Vas(SbF2)507ö(S03)\ 587617CuEv(S-O)1064 v(S-F)v(S-O) v(S-O) 8171350 1161(SO3)4221400 1200 1000 800 600 400 200110possibly incomplete. All three S-U stretching bands of [SbF2(SO3F)]x show more or lessresolved shoulders in the JR spectrum, which may be caused by factor-group effects or by theasymmetrical bridging configuration of the SO3F group, as evidenced by the molecularstructure. The distribution pattern of the bands in the SO3F stretching region is similar to thatobserved for (CH3)2Sn(SOF) (v(S-O) at 1351, 1189 and 1072 cm’, v(S-F) at 827 cm-’)and for [Pd(-CO)2J(SOF 2‘ (v(S-O) at 1311, 1202 and 1083 cm1, v(S-F) at 823 cnv’) intheir IR spectra. In these compounds, the fluorosulfate anions are arranged in a symmetricalbidentate bridging fashion, according to the molecular structures.36’7 This similarity is not sosurprising since the fluorosulfato groups in [SbF2( O3F)j may be approximately viewed assymmetrically bidentate ligands, as discussed in section 3.2.It is noted that in the JR spectra of (CH3)2Sn(SOF)36 and [Pd2(i-CO)](SF)y,the difference in frequency of the two S-O stretching bands of lower frequency is —118 cm-’.In these compounds, the SO3F group functions as a symmetrically 0-bidentate ligand and haslocal C symmetry. The S-U band at the highest frequency may be attributed to the stretchingvibration of the S-O bond, where the oxygen is not bonded to Sn or Pd atom. The two S-Obands of lower frequency may be taken to arise from the stretching vibration of the O-S-Omoiety with oxygens bonded to the metal atom. Of these two bands, the one at higherfrequency may be assigned to the asymmetric stretching mode of the O-S-O moiety while theone at lower frequency may be attributed to the symmetric stretching mode. The separation(118 cml) between the asymmetrical and symmetrical stretching bands of the 0-S-0 moietyseems characteristic for the symmetrically bidentate mode. The same separation (118 cm1) oftwo corresponding S-U stretching bands is also observed for Sn(SO3F)2,in which only minordifferences in length between two longer S-U bonds for each SO3F group (1.432(4) and1.420(3) A; 1.440(4) and 1.457(3) A) are found.28The difference in frequency of the two corresponding S-U stretching bands (1204 and1060 cnn) is as large as 144 cm-’ in the JR spectrum of [SbF2( O3F)}, reflecting the rather111significant deviation from symmetrical bidentate coordination of the SO3F group. In thestructure of [SbF2( O3F)], three significantly different S-O bond lengths (1.408(3), 1.4353,1.453(3) A) are observed for the SO3F group.The assignment of Sb-F stretching bands is much more difficult for [SbF2(SO3F)Jx thanfor the antimony(V) fluoride fluorosulfates, including SbF4(SO3F). In the latter case, it hasbeen suggested’244 that the oligomeric structure is linked by fluorosulfate rather than fluoride.The terminal Sb-F stretching vibrations fall into the 640-730 cm-’ region and are isolated fromthose due to the internal vibrational bands of the fluorosulfate group. While the infraredspectrum of SbF3 obtained by matrix isolation methods shows only three bands at 654, 624 and259 cm’, assigned to a discrete trigonal pyramidal SbF3 molecule of C3v symmetry, theinfrared spectrum of solid [SbF3] displays more bands. The bands due to Sb-F stretchingappear at lower frequency (603 cm-’) because of the strong interactions among SbF3 units viaasymmetrical fluoro bridging.38 For {SbF2(SO3F)]x, the Sb-F stretching bands are expected tofall into the same region. We tentatively assign an unusually intense Raman band at 562 cm1,with an IR counterpart at —‘565 cm’, to a symmetric Sb-F stretching vibration. Theasymmetric stretch is attributed to bands at —‘512 cm (IR) and 507 cm (Raman), a regionfree of SO3F bands both in (CH3)2Sn(SOF)6and [Pd2(J,t-CO)1(SO3F).7 The occurrenceof a symmetric stretch at higher wavenumbers than the corresponding asymmetric stretch iscommon for trihalides with pyramidal structures.39The vibrational spectra of [Sb(SO3F)3]x, shown in Figure 4-8, are considerably morecomplex. This is not unexpected because there are three nonequivalent fluorosulfate groups,for which nine S03-stretching bands and three S-F stretching bands are expected. While theRaman spectrum shows the expected numbers of bands, the infrared spectrum displays onlyeight 503-stretching bands and two S-F bands. The missing 503-stretching band and S-Fstretching band are possibly buried beneath other overlapped S-0 and S-F bands, respectively.112FT-Infrared440 407ci)C.)Cu625E429 I.—563 p(S03)607580 5501389 1341 12351209 1188 1074 1046 990 841 825YI yJv(S03) v(S-F) ö(S03)1400 1200 1000 800 600 400 200U(cm1)v(S-F)FT-Raman 871v(S03) t(SO3F)________ _________÷1D4t(SbO.)1207IE 6(S03) p(S03)_______2486271188 6111366 1232 1063 584 431839 5651339 1075 826 I ‘ 411 213 1471390 1440 / /549 398 171 1241400 1200 1000 800 600 400 200i’(cm’)Figure 4-8 Vibrational Spectra of [Sb(SO3F)]with approximate descriptions of thevibrational bands.113The relative intensities and positions of the stretching bands suggest strong vibrationalcoupling. It is inappropriate to assign each band to a single vibrational mode for the individualfluorosulfato group because of the strong vibrational coupling. It is also impossible to deducethe coordination geometry of antimony from the vibrational spectra. These structural analyseshave been possible for other binary fluorosulfates, e.g. [Au(SO3F)3]2,4°where the structure hasbeen confirmed by single-crystal X-ray diffraction,29 or for Sn(SO3F)4,41 with support from“9Sn Mössbauer spectroscopy, and for Pt(SO3F)4,2 or, more recently, for Zr(SO3F)4andHf(SO3F)4,3 which all give rise to much simpler vibrational spectra. Hence only limitedinformation can be obtained from the vibrational spectra. Band positions in the SO3 stretchingregion extend from 1390 to 990 cm-’, a considerably wider range than for [SbF2(SO3F)]x, suggesting stronger covalent interactions between antimony and the fluorosulfate. Bands at 518and 565 cm1, attributed to Sb-F stretching (vide supra), are now absent, as are the unusuallyintense Raman band at 562 cm-’ and the other Raman band at 507 cm-1.A surprising similarity is observed between the JR spectra for [Sb(SO3F)3]x and that ofthe powder from which the [SbF(SO3F)2]x crystal was prepared. Except for weak bands at668, 503, and 397 cm-’ and a slightly different shape of the band at 825 cm-’ observed fromthe latter spectrum, the two spectra are virtually identical in terms of band position, relativeband intensities and band shapes. Unfortunately the amount of crystalline [SbF(SO3F)2]xobtained was too small to obtain good-quality vibrational spectra and microanalysis, which wasinitially considered unnecessary in view of the completed structural determination for thismaterial. It must be concluded that the bulk material obtained in the manner described in theexperimental section is largely [Sb(SO3F)3]x. This example shows that mistakes can easily bemade where the composition of a material is inferred solely from a completed crystal structurewith single crystals obtained from the bulk material. Such mistakes are avoided by the use ofmicroanalysis and vibrational spectroscopy.1144.4. Summary and ConclusionsThe initial objectives of this study, to confirm the existence of antimony(I) fluorosulfate, Sb(SO3F), and to provide a more detailed characterization of this material, have not beenachieved. There is now considerable doubt as to whether antimony in the oxidation state +1exists in thermodynamically stable, isolatable compounds.An extensive study of the reactions between antimony and fluorosulfuric acid and/orS206F,and the subsequent development of specific synthetic routes produces single crystalsof the polymeric antimony(III) fluoride fluorosulfates—[SbF2( O3F)], [SbF(SO3F)2]x, and[Sb(SO3F)31x. Their structures have been determined by single crystal X-ray diffraction to ahigh degree of accuracy. Together with the previously reported structure of [SbF3]x, themolecular structures provide a detailed comparison for the series [SbFn(SO3F)3..n]x with n = 0,1, 2, or 3, and an insight into the complex coordination chemistry of Sb(III) fluoridefluorosulfates.Both ligands function as asymmetrical bidentate (F) or 0-tridentate (SO3F) bridgingligands. The Sb-O and Sb-F interactions in all four compounds range from normal covalentbonds (-‘2.0 A) to long intermolecular contacts (— 3.0 A), which is not adequately described bythe classical concepts of primary and secondary covalent bonding. Hence the concept ofintermediate bonds (—‘2.6 A), midway between covalent bonds and secondary contacts isintroduced. In the solid state, the covalent S-O bonds (2.0-’2. 1 A) for [Sb(SO3F)]produce atrigonal pyramidal structure, with very acute bond angles. Secondary S 0 interactions(2.8 -‘3.0 A) extend the coordination environment to a distorted trigonal prism, andintermediate bonds (2.55-’2.65 A) arranged in a almost trigonal planar coordination completethe nine-coordinate structure.The coordination number of antimony depends strictly on the available donor sites ofthe ligands and increases sequentially from six for SbF3 to nine for [Sb(SO3F)3]x. Thedifferent levels of Sb-0 and Sb-F interactions present a complicated bonding situation. The115coordination geometries are greatly distorted or irregular and defy descriptions using theVSEPR model. The intermediate bonds and secondary contacts play important roles in thecoordination geometry around antimony and in the polymeric structures of these antimonyfluoride fluorosulfates. The relative weakness of intermediate bonds and secondary contacts isreflected in the fact that all three materials will dissolve on mild heating in HSO3Fand can berecrystallized from this medium.116References1. 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Bartlett, N.; Wechsberg, M.; Jones, G. R.; Burbank, R. D. Inorg. Chem. 1972, 11, 1124.28. Adams, D. C.; Birchall, T.; Faggiani, R.; Gillespie, R. J.; Vekris, J. E. Can. J. Chem.1991, 69, 2122.29. Willner, H.; Rettig, S. J.; Trotter, J.; Aubke, F. Can. J. Chem. 1991, 61, 391.30. Mercier, R.; Douglade, J.; Theobald, F. Acta Crystallogr. 1975, B31, 2081.31. Mercier, R.; Douglade, J.; Bernard, 3. Acta Crystallogr. 1976, B32, 2787.32. Douglade, J.; Mercier, R. Acta Crystalogr. 1979, B35, 1062.33. Mallela, S. P.; Lee, K. C.; Aubke, F. Inorg. Chem. 1984, 23, 653.34. Levchuk, L. E.; Sams, J. R.; Aubke, F. Inorg. Chem. 1972, 11, 43.35. Zhang, D.; Aubke, F. I Fluorine C’hem. 1992, 58, 81.36. Allen, F.A.; Lerbscher, J.; Trotter, 3. J. Chem. Soc. A 1971, 2507.37. Wang, C.; Bodenbinder, M.; Willner, H.; Rettig, S. 3.; Trotter, J.; Aubke, F. Inorg. Chem.1994, 33, 779.38. Adams, C. J.; Downs, A. J. I Chem. Soc. (A), 1971, 1534.39. Nakamoto, K., Infrared Spectra of Inorganic and Coordination Compounds, John Wileyand Sons: New York, 2nd ed.; 1970; p 93.40. Lee, K. C.; Aubke, F. Inorg. Chem. 1979, 18, 389.11841. Yeats, P. A.; Poh, B. L.; Ford, B. F. E.; Sams, J. R.; Aubke, F. J. Chem. Soc. A 1970,2188.42. Lee, K. C.; Aubke, F. Inorg. Chem. 1984, 23, 2124.43. Mistry, F.; Aubke, F. J. Fluorine Chem. 1994, 68, 239.119Chapter 5THE CRYSTAL AND MOLECULAR STRUCTURES OFCESIUM SALTS OF SOME SUPERACID ANIONS5.1. IntroductionSuperacids are used as reaction media for the generation and stabilization of veryreactive, highly electrophilic organic and inorganic cations. The usefulness of a conjugatesuperacid is determined by three interrelated properties: the protonating ability of the system,the anion-accepting ability of the Lewis acid, and the weak nucleophilicity of the anions in thesystem.As indicated by the ‘9F NMR study discussed in Chapter 3, the composition of theHSO3F/ bF5system, where the Lewis acid has a different substituent (F-) from the conjugatebase ion (S03F) of the Brönsted acid, is very complex. Such conjugate superacids may betermed heteroleptic conjugate superacids. Besides the formation of the complex acid,H[SbF5(SO3F)] and proton transfer equilibria involving the complex acid and HSO3F, thereare other reactions such as oligomerization, ligand redistribution via P vs. 503Fexchange, andthe solvolysis of SbF5 in HSO3F. These reactions produce many species in equilibria. Theformation of the species and their concentration depends on the Lewis acid (SbF5)concentration. With various anions present in such equilibria, the growth of single crystals ofcompounds containing a particular anion from such a system appears to be a challenging task.Accordingly, a conjugate superacid system, where the substituents of the Lewis acid areidentical to the conjugate base ion of the Brönsted acid, is termed a homoleptic conjugatesuperacid. The composition of a homoleptic conjugate superacid system is expected to bemuch simpler. Besides association of the Brönsted acid with the Lewis acid and subsequentproton transfer equilibrium, only oligomerization of the Lewis acid and complex acids needs tobe considered. For example, as indicated by a ‘9F NMR study,6 the Sb(V) species present in120the HF/SbF5 system are limited to [SbF6], [Sb2F11], and possibly higher oligomers such as[Sb3F16f,etc., and their corresponding complex acids.In a homoleptic conjugate superacid system based on HSO3F and a binaryfluorosulfate, M(SO3F), the initial reaction between the Brönsted acid and the Lewis acid maybe represented by the following equation:2 HSO3F+ M(SO3F) HSOF + [M(SO3F)+1] [5-1]The Brönsted acidity of the system depends on the intrinsic proton donor strength and theconcentration ofH2SO3F’. The relative H2SO3Fconcentration in HSO3F-based conjugatesuperacids may be estimated by electrical conductivity measurements at low Lewis acidconcentrations.7 The overall protonating ability can be measured by the Hammett acidityfunction (-H0),8 provided that suitable Hammett base indicators are available. Both methodswill in turn provide information on the relative anion-acceptor ability, or the acid strength, ofthe Lewis acids studied. 9-14The third important property of the system, the nucleophilicity of [M(SO3F)], is notreadily measured or deduced. The anions in superacid systems, termed superacid anions, maybe isolated as salts with simple cations such as alkali metal cations. In this study, Cs is chosenas a counter cation, because it is the largest and least electrophilic alkali metal cation. It is alsostable towards oxidation or reduction in acidic media. Many cesium salts of superacid anionsare known and are soluble in HSO3F. The anions studied in this work are derived from theBrönsted superacid HSO3F, two homoleptic conjugate superacids, HSO3F/Au(SO)12andHSO3F/Pt(SO)4,’and the so far unknown conjugate superacid HSOF/Sb(SO)5.Thestructures of the anions in the solid state can be studied by spectroscopic methods includingone of the most definitive techniques — single crystal X-ray diffraction.In this chapter, the crystal and molecular structures of CsSO3F, Cs[H(SO3F)2],Cs[Au(SO3F)41,Cs2[Pt(SO3F)6]and Cs[Sb(SO3F)6]are presented and a correlation betweenstructure and weak nucleophilicity of the superacid anions is discussed.1215.2. Experimental5.2.1 Syntheses of CsSO3F,Cs[H(SO3F)21,Cs(Au(SO3F)4],Cs2[Pt(SO3F)6jandCs[Sn(SO3F)6Cs[H(SO3F)2]was obtained by the solvolysis of CsC1 in excess HSO3F. 15,16 CrudeCsSO3F powder was obtained by heating Cs[H(SO3F)2]in vacuo at 120°C for 3 days. Thecompounds Cs[Au(SO3F)4],Cs2{Pt(SO3F)6]andCs2[Sn(SO3F)61were synthesized accordingto published methods.12’3”7 However, CsSO3F was used instead of CsCI as the startingmaterial.5.2.2 Synthesis and Characterization of Cs[Sb(SO3F)61In a typical reaction, 0.169 g (1.00 mmol) of CsCI was added into one side arm of aninverted-Y-shaped reactor. About 10.5 g (105 mmol) of HSO3Fwas transferred into the otherside of the reactor inside the dry box. After the reactor was removed from the dry box, CsCIwas allowed to mix with HSO3F. The mixture was stirred at room temperature for about onehour. Hydrogen chloride produced during the reaction was removed intermittently. Thesolution was then kept under dynamic vacuum to remove all of the HCI. A slight loss ofHSO3Fat this stage was noted. Antimony powder (0.1206 g, 0.99 1 mmol) was then added tothe reactor inside the dry box. About 1.30 mL (2.24 g, 11.3 mmol) ofS206F,measured in agraduated measuring trap fitted with a Kontes Teflon stopcock, was transferred to the reactor invacuo. The mixture was stirred at room temperature overnight. All antimony was consumedwithin twelve hours to give a colorless solution. By removal of volatiles and HSO3Fin vacuo,the volume of the solution was reduced to about 3 mL. At this point, a colorless, crystallinesolid precipitated form the solution. Complete removal of the solvent yielded a crude productwith a yellow-orange color. To purify the compound, the raw product was recrystallized in Ca.3 mL of HSO3Fto give colorless, cubic crystals.The composition was established by the mass balance of the reaction and thesulfur content (analyzed to be 23.00% versus 22.66% calculated for Cs[Sb(SO3F)6]). The122‘9F NMR spectrum of a Cs[Sb(SO3F)6]solution in HSO3F was recorded. A sharp peak at6cI3=46.35 ppm (relative to CFCI3) and a solvent peak at 6cFcI3=40.86 ppm (HSO3F) wereobserved. The hygroscopic crystals of Cs[Sb(SO3F)6]decomposed to give a brown residue at149° C when heated in a sealed capillary tube.5.2.3 Preparation of Single CrystalsSingle crystals of Cs[H(SO3F)2j,Cs2[Pt(SO3F)6]and Cs[Sb(SO3F)6}were grown byallowing their hot, saturated solutions in HSO3F to cool slowly to room temperature. Singlecrystals of Cs[Au(SO3F)4]were grown from the corresponding solutions in HSO3F bycontrolled removal of the solvent in vacuo. Single crystals of CsSO3F were obtained byrecrystallization of crude CsSO3Ffrom deionized water. In the cases of the hygroscopic saltsCs[H(SO3F)2], Cs[Au(SO3F)4],Cs2{Pt(SO3F)6]and Cs[Sb(SO3F)61, the solutions wereseparated from the crystals using a pipette inside a dry box. The “wet” single crystals forX-ray diffraction study were mounted in 0.5 mm o.d. Mark capillary tubes made of Lindemannglass inside the dry box. The capillary tubes loaded with single crystals were temporarilysealed with Halocarbon grease inside the dry box and were flame-sealed immediately afterremoval from the dry box. A single crystal of CsSO3Fwas mounted on a glass fiber.X-ray crystallographic analyses were carried out by Dr. S. J. Rettig of this department.A list of crystallographic data, final atomic coordinates and equivalent isotropic thermalparameters, bond lengths, and bond angles for the five structures are listed in Appendix E.5.3. Results and Discussion5.3.1 Syntheses of CsSO3F,Cs[ll(SO3F)2j,Cs[Au(SO3F)4]Cs2[Sn(SO3F)61andCs2[Pt(SOF)6The synthesis of CsSO3F appears easy, since alkali metal chlorides undergo completesolvolysis in HSO3Fand the byproduct HCI can be easily removed from the reaction mixture.However, the crystalline product obtained upon reduction of the solvent (HSO3F) volume iscesium hydrogen bis(fluorosulfate), Cs[H(SO3F)2]. CsSO3F powder can be prepared by123heating Cs[H(SO3F)2]at 120—150 °C in vacuo. Crude CsSO3F can be recrystallized from aneutral aqueous solution. In acidic or basic aqueous solution, CsSO3F is hydrolyzed toproduce Cs2SO4or CsHSO4as the final products:72CsSO3F+ H20 2HF + Cs2SO4 [5-2]As reported previously,’2’13, 17 The cesium salts of the fluorosulfato metallates,Cs[Au(SO3F)4],’2Cs[Pt(SO3F)6]13 andCs2[Sn(SO3F)6]17, were obtained by oxidation of thecorresponding metals byS206Fin the presence of stoichiometric amounts of CsSO3F. In thepreviously reported method, the synthesis was carried out in two steps. The solvolysis of CsCIin HSO3Fproduces C5SO3F(soIv):CsCI + HSO3F HSO3F - C5SO3F(soIv) + HCI [5-3]This was followed by the oxidation of a stoichiometric amount of metal by an excess ofbis(fluorosulfuryl)peroxide,S206Fin HSO3Faccording to:flCSSO3F(soIv) + M + -52O6F HSO3F- Csn[M(SOF)m+nl [54](MAu, m=3, n 1;M=Pt or Sn, m=4, n=2)The byproduct, HC1, produced in the solvolysis of CsC1 in HSO3F must be removedcompletely from the solution before S206F is added. Residual HCI is frequently oxidizedstepwise to yield CIO2S3Feventually according to the overall equation:2HCI + 6S20F 2HSO3F+ 2C10S03F+ 4S205F [5-5]CIO2S3Fforms salts of the type [C10jM(SOF)6](M=Sn,’7Pt’3) or[Cl02][Au(SO3F)4In this study, CsSO3Fwas first prepared and purified. The purified CsSO3Fwas then used inthe synthesis of Cs[Au(SOF)4],Cs2[Sn(SO3F)6]and Cs[Pt(SO3F)6]according to:2CsSO3F+ 2Au + 3S206F HSO3F 2Cs[Au(SO3F)4] [5-6]2CsSO3F+ M + 2S06F HSO3F Cs2[M(SO3F)6] (M=Sn, Pt) [5-7]Thus, contamination of the products by CIO2S3Fwas completely avoided.1245.3.2 The Synthesis and Vibrational Spectra of CsISb(SO3F)61As discussed in Chapter 4, initial unsuccessful attempts to synthesize Sb(SO3F)5by theoxidation of antimony with excess S206F have led to the synthesis and structuredetermination of [SbF2( O3F)], [SbF(SO3F)2]and [Sb(SO3F)]. In spite of its polymericnature, [Sb(SO3F)]has appreciable solubility in HSO3F, which should facilitate theoxidation of Sb(III) to Sb(V) withS206F. Sb(SO3F)5may form as an isolatable compound inthe oxidation of Sb(SO3F) with excess S206F. Alternatively, Sb(SO3F)5(soIv) may begenerated in situ in HSO3F, in a manner similar to the generation of Nb(SOF)(soIv) andTa(SO3F)5(solv) reported recently.’4 In the presence of CsSO3F, the formation of the complexanion [Sb(SO3F)6]by accepting an SO3Pion is evidence of the Lewis acidity of Sb(SO3F)5:Sb(SO3F)5(solv)+ S03F 25C,12 his. [Sb(SO3F)6]- [581The synthesis of the new compounds Cs[Sb(SO3F)6]is accomplished by a two-stepreaction, analogous to the method reported for Cs[Au(SO3F)4J,’2Cs[Pt(SO3F)6],13 andCs2[Sn(SO3F)6].’7 The salt is isolated in almost quantitative yield. The crude product isslightly yellow, probably due to the contamination by chioryl compounds. Recrystallizationfrom HSO3Fproduces colorless, cubic crystals suitable for single crystal X-ray diffraction.The vibrational spectra of Cs[Sb(SO3F)6]are shown in Figure 5-1. The simplicity ofthe spectra suggests a highly symmetrical anion. The spectral pattern of four bands in theSO3F stretching region (700-1600 cm’) of both IR and Raman spectra clearly indicates thepresence of monodentate fluorosulfate groups. The vibrational bands for Cs[Sb(SO3F)6]arelisted in Table 5-1, together with those of some other fluorosulfato metallates. ForCs[Sb(SO3F)6],the frequency of the v(S-O) band is much lower and the frequency of thev(SO2)band is significantly higher than those of the corresponding bands inCs2[Sn(SO3F)6],Cs[Pt(SO3F)61and Cs(Au(SO3F)4]. This implies that the S-O bond with the oxygen atombonded to antimony is weakened and the other S-O bonds are strengthened.125FT-Infrared Spectrum/10125414511231 /\958 97 /\928 821 573 550 316I I I I I I1600 1400 1200 1000 800 600 400 2005(cm1)2731256FT-Raman Spectrum617II.—258432 /I 567 177 164541 40082914441228/ 931600 1400 1200 1000 800 600 400 200Ai5 (cm-1)Figure 5-1 Vibrational Spectra of Cs[Sb(SO3F)6].126Table 5-1 Frequency and relative intensity of vibrational bands (cm’) for Cs[Sb(SO3F)6],Cs2[Sn(SO3)6],andCs2[Pt(SO3F)6].Cs[Sb(SO3F)6] Cs2[Sn(SO3F)61 Cs2[Pt(SO3F)6] ApproximateIR Raman IR Raman IR Raman Description(this work) (this work) (this work) (ref.17) (this work) (ref.13)1451 s 1444ms 1399s 1407m 1406 vs 1416 w,sh v(SO2)1399m 1345vw 1410m1254vw,sh 1256 vs 1265 w,sh 1270s 1345vw 1250 vs v5(SO2)1231s 1228w,sh 1224s 1218w 1213vs 1219m1026 vw958 m, sh 903 w 1088 w,sh 1091 s 1041 w 1043 s928 vs 1015s 995 sh 969vs lOlOm v(S-O)897 m,sh 927 m, sh +821 vs 829 ms 809 s 828 m 799 s 800 w, b v(S-F)811 m644 ms 617 s 632 s 625 s 657 m 634 vs573s 567w 577ms 578ms 584s 579vw M-O550s 541w 556ms S6Oms 547m 550vw V449m 432m 435m 431m 452w 444m +408w 400w,sh 410w 418 v/cl,’407 o316s 345w273 s 260 m 280 vs t (MOn)258 w,sh +7m‘r(SO3F)5.3.3 Description of Crystal Structures of CsSO3F,Cs[H(SO3F)2],CsIAu(SO3F)41,Cs2[Pt(SOF)6],and CsjSb(SO3F)61Some crystallographic data of the five compounds are listed in Table 5-2. As seen fromTable 5-2, all crystal structures have been determined with low R values except that ofCs2[Pt(SOF)]The crystal structure of CsSO3Fhas been determined in this study with high precision(R=0.029, Rw0.027). The space group P21/a is different from the reported space group(14/a) determined in a very early study based on macrocrystallography. 18 It is possible thattwo different crystalline forms of CsSO3Fexist.127Table 5-2 Crystallographic data for Cs(SO3F), CsH(SO3F)2Cs[Au(SO3F)4],Cs2[Pt(SO3F)6]and Cs[Sb(SO3F)6j.Compound Cs(SO3F) CsH(SO3F)2Ds[Au(SO3F)4I Cs2IPt(SO3F)61 Cs[Sb(SO3F)61Formula 231.96 332.63 726.10 1055.24 848.99weightCrystal monoclinic monoclinic monoclinic trigonal trigonalsystemSpace P21/a C2/c C2/c P321 P.3groupa (A) 7.7243(6) 13.37 1(2) 17.725(2) 9.070(1) 12.03 17(7)b (A) 8.1454(6) 7.73 1(2) 5.822(2) 9.070(1) 12.03 17(7)c (A) 7.7839(7) 9.485(2) 14.624(2) 7.6028(7) 12.026(2)(°) 110.832(7) 128.375(7) 102.120(9) 90 90V (A3) 457.72(7) 768.6(3) 1475.5(5) 541.64(6) 1507.6(2)Z 4 4 4 1 3R (F) * 0.029 0.027 0.030 0.048 0.039R (F)** 0.027 0.026 0.029 0.045 0.037* R= (ZIIF0IFI)/ZI**= zw(FoI_IFI)2/EwIFoI2)Y2The molecular structure of CsSO3Fis depicted in Figure 5-2. In CsSO3F, the S-F bondlength is 1.569A. There are two S-O bonds with equivalent bond lengths (1.437(2)A and1.436(2) A) and one slightly longer S-O bond (S1-O1=1.458 A). The environment of theanion is shown in Figure 5-2. The distances between Cs and the nearest 0 and F range from3.115(2) A to 3.329(2) A for Cs••O and 3.252(2) A for Cs•”F, indicating rather weak cation128Cs I *Cs 1 *02SI’03 03*02*Csi *1.436(2 Si 03*Csi* CsICsi* $‘ •%0101*FlF1*01*Csl *Cs 1 *Interatomic distances (A):Si-Fl 1.569(2) FlCs* 3.252(2) S1-Oi 1.458(2) OlCs* 3.329(2)O1Cs* 3.220(2)S1-02 1.437(2) 02Cs* 3.223(3) S1-03 1.436(2) O3Cs* 3.151(2)O2Cs* 3.265(2) 03Cs* 3.31 6(3)02Cs* 3.115(2) O3Cs* 3.119(2)Selected bond angles (°):LF1-Sl-Oi 102.3(1)° LF1-Si-02 106.3(1)° LF1-S1-03 107.8(1)°LOi-Si-03 112.7(1)° L01-S1-02 113.6(1)° L02-Si-03 113.2(1)°Figure 5-2 ORTEP view of the structure of CsSO3F(33% probability thermal ellipsoids areshown). V129anion interactions. All Cs•• .0 interatomic distances are different from one another. Theoverall coordination number of Cs is 9.The crystal structures of other simple fluorosulfates, LiSO3F, 19 KSO3F, 20 andNH4SO3F21 have been determined previously. The structures are less reliable than CsSO3F(R0.073 and R=0.094 for LiSO3F, R0.069 for KSO3F, and R=0.078 for NH4SO3F). As acomparison, the bond lengths and bond angles of the anion are listed in Table 5-3, togetherwith those previously published for other simple fluorosulfates. In the lithium salt, the stronglypolarizing cation, Li, is tetrahedrally coordinated to four oxygen atoms and two Li04 unitsshare a common edge to form an isolated Li206 moiety. The bridging Li-O bond length is2.045(10) A. The terminal Li-O bond length (1.903(10) A) is in the range of the shortestTable 5-3 Structure parameters of fluorosulfate anion in alkali metal fluorosulfates andNH4SO3F.Structure Parameter CompoundLiSO3F KSO3F NH4SO3F CsSO3FBond Length (A) (ref. 18) (ref. 19) (ref. 20) (this work)S-O(1) 1.455(6) 1.458(2)S-0(2) 1.424(4) 1.424(9) 1.45 1.437(2)S-0(3) 1.424(4) 1.436(2)S-F 1.555(7) 1.57(2) 1.55 1.569(2)Bond angle (°)F(1)-S-0(1) 104.5(5) 102.3(1)F(1)-S-0(2) 102.8(3) 105.8 106 106.3(1)F(1)-S-0(3) 102.8(3) 107.8(2)0(1)-S-0(2) 113.5(2) 113.6(1)O(1)-S-0(3) 113.5(2) 112.9 113 113.2(1)0(2)-S-0(3) 117.4(4) 112.7(1)130Li-O distance (1.82-1.96 A) found in the other structures.2224 In the structures of KSO3FandNN4SO3F, the anion is disordered. In the crystals of KSO3F, the fluorosulfate anion isarranged in a completely disordered manner. In the crystals of NH4SO3Fabout 25% of thefluorosulfate anions are present in the second orientation. The disordered arrangement of theanions limits the precision of the structure determination. The structure of CsSO3Fdeterminedin this study represents the first ordered structure of a simple ionic fluorosulfate.The crystal structure of Cs[H(SO3F)2]determined in this study is more reliable(R=O.027, R=O.O26) than in a preliminary and incomplete work (R=O.044).’6 In the previouswork,16 the position of hydrogen atom was not located. It was assumed that the hydrogen atomwould lie at the a crystallographic inversion center.’6 In this study, the hydrogen atom islocated at the center of symmetry from a difference map. A linear, symmetrical hydrogenbond of the type O . . O links two SO3F groups (Figure 5-3 a). There are some examples ofhydrogen bonds of the O• . . .0 type, e.g. in K[H(CF3COO)2],5 [Cs[H(N032],5 [N(nBu)4][H(OTeF5O2,6etc. The 0 0 distance in Cs[H(SO3F)2j(2.421(5) A) is shorter thanthose in Cs[H(N03)2] (2.45 A), [N(n-Bu)4][H(OTeF5O)2 (2.595(8) A) and inK[H(CF3COO)21(2.437 (4)A).As discussed in Chapter 3, in [H30j[Sb2F1J, the bent and asymmetrical hydrogenbonds of the type O—HF link [H3Oj and [Sb2F1i] ions into a 3-dimensional network. InCs[H(SO3F)2], in contrast, the linear and symmetrical O• . •O hydrogen bond links twoSO3F groups to form an isolated entity. The Cs has crystallographic C2 symmetry. Alloxygen and fluorine atoms in the SO3F group, including the oxygen bonded to hydrogen, areinvolved in the coordination to Cs. The Cs...F distance is 3.303(2) A and the Cs•••O distancesvary from 3.13 1(2) A to 3.530(3) A. The coordination number of cesium in Cs[H(SO3F)2]is12 (Figure 5-3b), which is the same as in Cs[Sb(SO3F)6j. In Cs[H(SO3F)2J,however, thefluorine atom of the SO3F group is involved in the coordination to Cs, which is not the casefor Cs[Sb(SO3F)6](vide infra).131Li.S(1)-F(1) 1.531(2)S(1)-0(1) 1.406(2)HIS(1)-0(2) 1.399(3)0301 S(1)-0(3) 1.471(2)Si O(3)-H(1) 1.210(2)02Flb. Cs 1 *01* S1Csl* 02) 03* 02* Cs(1)F(1)* 3.303(2)Fl Si01 77F1* Cs(1)-0(1) 3.131(2)03Cs(1)_0(1)* 33(3)Hi \\\ 02 Cs(1)_0(2)* 3.196(3)Csl* 03* \\ 02* F1* Cs(1)_0(2)** 3.530(3)01* Cs(1)0(3)* 3.464(2)Figure 5-3 Structure of Cs[H(SO3F)2]: a. H(SO3F)2 ion; b. coordination environmentof Cs ion (33% probability thermal ellipsoids are shown; bond distance in A).132The bonding mode of the SO3F group is monodentate in Cs[H(SO3F)2]. The bondlength of S1-03 (1.471(2) A), where 03 is involved in hydrogen bonding, is significantlylonger than the other two S-0 bond lengths (1.406(2)A) and (1.399(3) A), where the oxygensare involved in cation-anion interactions with Cs. The S-F bond length is shortened to1.53 1(2) A from 1.562(2) A in CsSO3F.The [Au(S03F)4jion has exact C1 symmetry (Figure 5-4a). Gold is coordinated tofour monodentate SO3F groups. As expected for Au(III) (d8 electronic configuration), formost Au(III) compounds a square planar coordination environment around the metal center isfound.27’8 In [Au(SO3F)4],the oxygen atoms bonded to gold are arranged in a very slightlydistorted square plane. The Au-0 bond lengths (1.968(4) A and 1.976(4) A) are equivalentwithin error limits. The 0-Au-U bond angles (88.8(2)’ and 91.2(2)’) deviate very slightlyfrom a right angle (900). The SO2F moieties of two adjacent fluorosulfate moieties rise abovethe Au04 coordination plane while those of the other two fluorosulfates point below the plane(Figure 5-4a). Similar molecular structures can be found for [Au(SO3F)]29 andK[Au(N03)4].° In the dimer [Au(SO3F)]2,the Au04 plane is distorted, because the Au-0bonds between Au and monodentate, terminal SO3F groups (dav(Au-O)t=l .957A) are strongerthan those between Au and bidentate, bridging SO3F groups (dav(Au-0)b=2.018A).29 TheAu-0 bond lengths (dav(ATh0)1 .972 A) in the symmetrical [Au(SO3F)4] ion are shorterthan the average Au-0 bond lengths in K[Au(N03)4j(2.005 A) and in the neutral dimer[Au(SO3F)J2(1.988 A).Within each SO3F group, the S-U bond with the oxygen coordinated to Au(III) islonger than the other two S-U bonds and the S-F bond. As shown in Figure 5-4b, one of thefluorosulfate groups is two-fold disordered. S2 and F2 are disordered by reflection in the04-05-06 plane. The Cs ion is 10-coordinate and has exact C2 symmetry. All oxygen atomsare involved in the coordination of cesium cation.133F( 1)Au(l)-0(l) 1.968(4)0(3) S(l)-0(l) 1.508(4)0(2) S(l) S(l)-0(2) 1.393(5)S(1)-0(3) 1.402(6)91.2(2)° 0(1) S(l)-F(i) 1.523(6)88.8(2)°Au(l) 0(5) Au(l)-0(4) 1.976(4)F(2)- S(2)-0(4) 1.44(1)S(2)-0(5) 1.35(1)0(4)S(2) S(2)-0(6) 1.41(1)S(2)-F(2) 1.56(1)0(6)a03*05* 02*06*Cs(1)-02 3.115(5)06* Cs(1)-05 3.202(5)F2a* Cs(l)_03* 3.295(6)F2a*Csl Cs(1)06* 3.177(7)Csi* Cs(1)_F2a* 3.56(3)05 F2aS2a02 03*S2 Csl*03 Si F206Fl 0404*01 Aul 01* bFigure 5-4 Structure of Cs{Au(SO3F)41(33% probability thermal ellipsoids are shown; bondlengths in A): a. [Au(SO3F)4fion (disorder of the S(2) fluorosulfate group isnot shown); b. coordination environment of Cs in Cs[Au(SO3F)4].134As shown in Figure 5-5 a, the [Pt(SO3F)6]2-ion has exact D3 symmetry. Platinum iscoordinated to six monodentate fluorosulfato groups. The oxygen atoms are arranged in adistorted trigonal prism with the top face twisted slightly against the bottom face. The Pt-Obond length is 1.987(8) A. All six fluorosulfates are symmetry related. The Cs ion has exactC3 symmetry (Figure 5-5b). The fluorine and oxygens that do not bond to platinum areinvolved in the coordination of cesium. This gives an overall coordination number of nine forcesium.The structure ofCs2[Pt(SO3F)61is less reliable (R0.048 and R =0.045) than all othercrystal structures reported in this study. Consequently the estimated standard deviations,particularly for the internal bond parameters of SO3F groups are relatively large. In spite oflarge estimated standard deviation values, the average bond length for the S-F and S-O bondswith fluorine and oxygen atoms unbounded to platinum are short.An ORTEP drawing of the [Sb(SO3F)6jion is shown in Figure 5-6a. The anion hasexact S6 symmetry. Antimony is coordinated by six symmetry related SO3F groups.Consistent with the conclusion obtained from the vibrational spectra, the SO3F groups arestrongly bonded to antimony in Cs[Sb(SO3F)6]. The Sb-O distance of 1.955(2) A is about 0.1to 0.15 A shorter than in [Sb(SO3F)],but slightly longer than in the recently reported anion[Sb(OTeF5)6](1.87(1) to 1.92(1) A).31 The short Sb-O bond is accompanied by a lengtheningof the corresponding S-O bond. The S-O bond length (1.5 16(2) A) is much longer than thosein CsSO3F (1.458(2), 1.437(2), and 1.436(2) A). Very strong bonding is observed for theother two S-O bonds and the S-F bond within each fluorosulfate group in the anion. The shortS-F bond length of 1.486(3) A is unprecedented among anionic and neutral sulfur-fluorinederivatives and even shorter than that in S02F(1.530(2) A).32 The terminal S-O bond lengthsfound for [Sb(SO3F)6] (1.409(4) and 1.396(3) A) are comparable to those in gaseous S02F(1.397(2) A), even though both oxygen atoms in [Sb(SO3F)61 are weakly coordinated tocesium cations. They are the shortest sulfur-oxygen bonds observed in neutral or anionic13503Si02Pt’01 Pt(1)-0(1) 1.987(8)S(1)—0(1) 1.44(1)S(1)-0(2) 1.48(2)S(1)—0(3) 1.36(1)S(1)-F(1) 1.555(9)02*03* Csl*FPcCsiCslJ03* FlCs(l)-F(1) 3.371(9)02Si01 Cs(1)-0(2) 3.10(1)F1*F1* Cs(l)-0(3) 3.184(9)02* ti01* 01* 01*01*b.Figure 5-5 Structure ofCs2[Pt(SO3F)6]:a.[Pt(SO3F)6]2 ion; b. environment of Cs Ion.(33% probability thermal ellipsoids are shown, bond lengths in A).136a.F1 Sb(l)-0(1) 1.955(2)S(1)-0(1) 1.516(2)S( 1 )-0(3) 1.409(4)S(1)-F(l) 1.486(3)S(1)-0(2) 1.396(3)02*b. 03* Csl *02* 02* Fl03Si 0203*01*03* 01*Csl03*01b102*01* 01*01*02*Cs( l)_0(2)* Cs( l)—0(3) S(l)-F( 1) S( l)—0(2) S( 1 )—0(3) S(1)—0( 1)3.241(3) 3.413(4) 1.486(3) 1.396(3) 1.409(4) 1.516(2)Figure 5-6 Structure of Cs[Sb(SO3F)6j:a). [Sb(SO3F)6]ion; b). environment of Cs Ion.(33% probability thermal ellipsoids are shown; bond lengths in A).137sulfur-oxygen compounds. Only for the cation OSF3 are short S-F bond (1.44(1) A) and S-Obond lengths (1.35(1) A) reported.33 Appreciable multiple-bond character is suggested for bothS-O and S-F bonds.As seen in Figure 5-6b, the Cs ion has exact C3 symmetry and is 12-coordinate. Theoxygen atoms of the SO3F group which are not bonded to antimony are coordinated to cesiumion via long contacts (3.241(3) and 3.413(4) A). Fluorine atoms are not involved significantlyin the coordination to Cs, as is evident from the large thermal ellipsoids in Figure 5- Structural Comparison of the Superacid Anions [H(SO3F)21,[Au(SO3F)41,[Sb(SO3F)61,and [Pt(SO3F)612In homoleptic conjugate superacids, the superacid anion may be described as a Lewisacid-base adduct of a monatomic cation, and fluorosulfate anions. For example,[Sb(SO3F)6]may be viewed as an adduct of a hypothetical Sb5 cation and six SO3F anions.The high electrophilicity of these cations is expected to manifest itself in short, strong M-O(M=Sb, Pt, Au or H) bonds. Such strong bonding of SO3F groups to the central cation throughthe bridging oxygen atom causes lengthening of the corresponding S-O bonds. Due toinductive effects, the S-F and other two S-O bonds within the same SO3F group aresubsequently shortened.Because of the differences in radii, oxidation states, and coordination numbers of thecentral atoms M, the comparison of M-O distances (M=H, Au, Sb, or Pt) in these complexanions is not useful. The relative strength of the M-O bonds may be determined by comparingM-O bond lengths in superacid anions with those in the compounds containing same centralatom in the same oxidation state. As can be seen in Table 5-4, all M-O (M=H, Au, Sb, or Pt)bonds in the corresponding superacid anions are indeed very short. The bond length of thelinear, symmetrical 0 . •O bond seems the shortest of the type and also shorter than theO 0 distances of asymmetrical O-H . •O hydrogen bonds reported for some salts of variousdicarboxylic acids.34 The Au-O bond lengths in [Au(SO3F)4j(1.968(4) and 1.976(4) A) are138Table 5-4 M-O bond and O 0 bond lengths in superacid anions and related compounds.Bond type Anion species bond length (A) Source0 0 Cs[H(SO3F)2] 2.420(2) (linear, H-centered) This work2.41 (1) (linear, H not located) ref. 16KH(CF3COO) 2.437(4) (linear, H-centered) ref. 35[N(n-Bu)4]H OTeF5)2j 2.595(8) (H not located) ref. 26Cs[H(N03)2] 2.468 (ZOH”.O=172.6°) ref. 25Au-O Cs[Au(SO3F)4J 1.968(4) (x2),1.976(4) (x2) This work[Au(SO3F)]2 1.956, 1.959, 2.016, 2.020 ref. 29K[Au(N03)4] 2.02 (x2), 1.99 (x2) ref. 30K[Au(OH)4] 1.980 (x4) ref. 36Sb0 Cs[Sb(SO3F)6] 1.955(2) (x6) This work[N(CH)4][Sb OTeF5 1.87(1) (x2), 1.88 < ref. 31Pt0 Cs[Pt(SO3F)6] 1.987(8) (x6) This workK[Pt(OH)6] 2.05 (x6) 37intermediate between the two different Au-O bond lengths in the dimer [Au(SO3F)]2:9 —1.96A for terminal, monodentate SO3F groups and —2.02 A for bonds to I.L-bidentate SO3F groups.The average Au-O bond length in [Au(SO3F)4] (1.972 A) is slightly shorter than that in[Au(SO3F)]2(1 .988A). Slightly longer Au-O bonds are also found for [Au(NO3)4].°Onlyin [Sb(OTeF5)61’are the Sb-O bonds slightly shorter than those in [Sb(SO3F)61.It is interesting to compare the internal bond lengths and bond angles of thefluorosulfate groups in the anions. Of particular interest are the S-O and S-F bonds withoxygen and fluorine atoms at the periphery of the complex anions. These peripheral oxygenand fluorine atoms of the complex anions are most likely to interact with electrophiles.139Comparison of the peripheral S-O and S-F bonds to the sum of the covalent radii (1.75A for SO and 1.73A for S-F)38 suggests appreciable multiple bond character for both S-O and S-Fbonds. For the SO3F group where sulfur(VI) is tetrahedrally coordinated, pic—di bonding,originally suggested by Cruickshank,39 may be used to describe the suggested multiple bondcharacter of S-O and S-F bonds. This bond type involves dative ir-bonding from lone pairelectrons in filled p-type orbitals on oxygen or fluorine to empty 3dz2 and3dx2-y on sulfur.The formation of the pit—>dit dative bonds reduces the electron density on oxygen or fluorineatoms. Reducing the electron density of peripheral atoms contributes to the very weaknucleophilicity of the superacid anions. Short S-O and S-F bond lengths suggest appreciablemultiple bond character of these bonds. Therefore, the nucleophilicity of the complex anionsdepends largely on the strength of peripheral S-O and S-F bonds.The SO3F group in complex anions are drawn in Figure 5-7. The interionic contacts toCs are neglected in the drawing. As references, the SO3F ion in CsSO3F and the S02Fmolecule 32 are also included. In CsSO3F, relatively long S-O (av. l.444A) and S-F(l.569A)bond lengths are found. In S02F, S-O and S-F bonds are the shortest among neutral andanionic species.Coordination of the SO3F ions to the central cation results in a substantial shorteningof all S-F and those 5-0 bonds that are not involved in coordination to M, i.e. the peripheralS-F and S-O bonds in the complex anions. As seen in Fig 5-7, all peripheral S-0 and S-Fbonds in all four complex anions are very short. In all cases, S-O bond lengths are about1.40A, comparable to bond lengths found in gaseous S02F. The S-F bond lengths are shorterthan that in SO3Fin ionic CsSO3F. For example, the peripheral S-0 and S-F bond lengths inthe symmetrical complex anion [Au(SO3F)4Jare 1.393(5) and 1.402(6) A for the S-0 bondsand 1.526 (6) A for the S-F bond. These short peripheral S-0 and S-F bonds suggest veryweak nucleophilicity of the anion. In fact, the corresponding HSO3F/Au(SO)system’2 is astronger conjugate superacid than the HSO3F/ bF5system (the “Magic acid”).140Au 1.968(4)FPt1.987(8)0’d.SO3FgroupinCs[Au(SO3F)4].e.SO3Fgroupin[Sb(SO3F)6]£S02Fmolecule102.3(1)°106.3(1)°107.8(2)° F£F-S-O1LF-s-o2LF-S-03104.8(2)°105.3(2)°107.7(1)LO1-S-02113.6(l)’LO1-S-03112.7(1)°L02-S-03113.2(1)°02LF-S-O1ZF-S-02ZF-S-03ZF-S-O1ZF-S-027F-S-03LOl-S-02I16.3(2yLO1-S-o3113.8(1)°702-S-03113.0(2)°FLF-S-Ol100.6(9)°LF-s-o2102(1)°LF-S-03104.5(10)°L0l-S-02111.6(8)’Lol-s-03114(1)L02-S-03120(1)°03a.SO3PinCsSO3FH1.210(2)03b.SO3FgroupinCs[H(SO3F)2]101 .7(3)°105.1(4)°104.3(4)°ZO1-S-02112.4(3)’LO1-S-03107.5(3)°702-S-03123.3(3)°027F-S-O1ZF-S-02ZF-S-0303103.5(l)°101.1(2)°106.4(2)°C.SO3FgroupinCs2[Pt(SO3F)6]F.11LF-S-FLF-S-OLo-S-O96.7(1.l)108.6(0.2)°122.6(1 .2)°401-S-02108.0(2)°LO1-S-03109.0(2)°L02-S-03117.9(2)°F00C’‘S0203Sb011.955(2)02F03Figure5-7Structuralcomparisonof SO3Fgroupsinsuperacidanions(bondlengthsinA).The peripheral S-O and S-F bonds are shortened in [Sb(SO3F)6] ion to a moresignificant extent due to the strong bonding of the SO3F groups to Sb(V). The bond lengths ofperipheral S-O and S-F bonds are the shortest among the anionic sulfur-fluorine species. Anextremely short S-F bond is found in [Sb(SO3F)6]. In [Sb(SO3F)61,the peripheral 0 and Fatoms form an eighteen atom polyhedron (Fig 5-6a). The nearest non-bonded contacts betweenthese atoms (3.235—3.496A for 3.3 19 and 3.418 A for O”F and 2.987 A for F...F) areonly slightly longer than the sum of the van der Waals radii (3.04A for O••O, 2.99A for O••Fand 2.94A for F .F).4° This means that repulsion between peripheral atoms is expected to besmall and will hence not weaken S-U and S-F bonds appreciably. From its structure, it issuggested that [Sb(SO3F)6]is a very weakly nucleophilic and poorly coordinating anion.It should be mentioned that single crystals ofCs2[Sn(SO3F)6]have been obtained andseveral sets of diffraction data have been acquired. Unfortunately, the structure has not beensolved and the exact space group is not known so far. [Sn(SO3F)6]2 and [Sb(SO3F)6] areisoelectronic and have different ionic charges. A structural comparison between the two anionsis expected to be interesting.In [Pt(SO3F)6}2,the S-0 bond lengths average to —1.40A but are difficult to interpretbecause of the rather large e.s.d. values. The structure ofCs2[Pt(SO3F)6]is less reliable thanany other structure reported in this study. From the peripheral S-U and S-F bond lengths, it isexpected that the nucleophilicity of [Pt(SO3F)6]2may be not as weak as that of [Au(SO3F)4],and that the corresponding complex acid H[Pt(SO3F)6J may be not as strong asH[Au(SO3F)4J. This is consistent with the results from an electrical conductometric study ofthe HSOFIPt(SO)system.’3When the weak nucleophilicity of the superacid anions and the low ionic potential ofCs is considered, the interactions between anions and cesium cations are expected to be weak.The coordination environments of the Cs ion in the five compounds are compared inTable 5-5. The interatomic distances are -‘3.10 A or longer for CsO contacts and -‘3.25 A or142Table 5-5 Coordination environment of Cs in cesium salts of superacid anionsCompounds Coordination Cs 0 contacts Cs”F contactsNumber interatomic interatomicNumber distance (A) Number distance (A)CsSO3F 9 8 3.115—3.265 1 3.252Cs[H(SO3F)2] 12 10 3.131—’3.530 2 3.303Cs[Au(SO3F)4] 8 6 3.115—’3.295 2 3.56Cs[Pt(SO3F)6] 9 6 3.10—3.184 2 3.3713.241 (x6)Cs[Sb(SO3F)6J 12 12 3.413 (x6)longer for Cs F contacts. Oxygen atoms are more likely to be the potential donor atoms thanfluorine atoms in these superacid anions. In salts with more electrophilic cations than Cs,these contacts are expected to be stronger and may contribute significantly to the structures ofthe compounds in solid state.It is noted that the Cs0 contacts in Cs2[Pt(SO3F)6](3.10(1) and 3.184(9) A) areslightly shorter than in Cs[Sb(SO3F)6](3.241(3) and 3.413(4) A). In contrast to the regularstructure of [Sb(SO3F)6], [Pt(SO3F)6]2 is distorted towards a nearly trigonal prismaticconfiguration. More extensive Cs 0 and Cs •F contacts in the [Pt(SO3F)6]2 ion than in[Sb(SO3F)6]appear to be a probable cause for the distortion.5.4. ConclusionsFrom the Brönsted superacid HSO3Fand conjugate superacids, the HSO3F/Au(SO)and HSO3F/Pt(SO)4systems, CsSO3F, Cs[H(SO3F)21,Cs[Au(SO3F)4]andCs2[Pt(SOF)6]have been isolated. In addition, a new compound, Cs[Sb(SO3F)6j,has been synthesized andcharacterized. The structures of all five compounds have been determined by single crystalX-ray diffraction.143In the complex anions studied, strong coordination of the SO3F group through oxygenstrongly to the central atom in a high oxidation state results in very strong, short peripheral S-Oand S-F bonds. For these bonds, enhanced pit-die multiple bonding is suggested. As aconsequence, electron densities on the peripheral oxygen and fluorine atoms and hence thenucleophilicity of the complex anions are greatly reduced. The exceptionally strong peripheralS-0 and S-F bonds of the highly symmetrical complex anion [Sb(SO3F)6]suggests its veryweak nucleophilicity of the complex anion. It is anticipated that the anion should be useful inthe stabilization and isolation of highly electrophilic cations, and that the HSO3F/Sb(SO)5system should be a very strong HSO3Fbased conjugate superacid.144References1. Gillespie, R. J. Acc. Chem. Res. 1968, 1, 202.2. Olah, G. A.; Prakash, G. K. S.; Sommer, J. Superacids; John Wiley & Sons: New York,1984.3. O’Donnell, T. A. Superacids and Acidic Melts as Inorganic Chemical Reaction Media;VCH Publishers: New York, 1993.4. Gillespie R. 3.; Passmore, J. in Advances in Inorganic Chemistry and Radiochemistry;Eds. Emeleus, H. J.; Sharpe, A.G.; Academic Press: N.Y., 1975, Vol. 17, p 49.S. Aubke, F.; Wang, C. Coord. Chem. Revs. 1994, 137, 483.6. Gillespie, R. 3.; Moss, K. C. J. Chem. Soc. (A) 1966, 1170.7. Thompson, R. C. in Inorganic Sulfur Chemistry; Ed. Nickless, G.; Elsevier: Amsterdam,1968; p 587.8. Hammett, L. P.; Deyrup, A. J. J. Am. Chem. Soc. 1932, 54, 2721.9. Gillespie, R. 3.; Peel, T. E. J. Am. Chem. Soc. 1973, 95, 5173.10. Gillespie, R. J.; Ouchi, K.; Pez, G. P. Inorg. Chem. 1969, 8, 63.11. Thompson, R. C.; Barr, J.; Gillespie, R. J.; Milne, 3. B.; Rothenbury, R. A. Inorg. Chem.1965, 4, 1641.12. Lee, K. C.; Aubke, F. Inorg. Chem. 1979, 18, 389.13. Lee, K. C.; Aubke, F. Inorg. Chem. 1984, 23, 21.24.14. Cicha, W.; Aubke, F. J. Am. Chem. Soc. 1988, 111, 4328.15. Josson, C.; Deporcq-Stratmains, M.; Vast, P. Bull. Soc. Chim. Fra. 1977, 9-10, 820.16. Belin, C.; CharbOnnel, M.; Potier, J. J. Chem. Soc., Chem. Commun. 1981, 1036.17. Mallela, S. P.; Lee, K. C.; Aubke, F. Inorg. Chem. 1984, 23, 653.18. Seifert, H. Z. Kristallogr. Mineralog. Petrogr. 1942, 104, 385.19. Zak, Z.; Kosicka, M. Acta Crystallogr. 1978, B34, 38.14520. O’Sullivan, K.; Thompson R. C.; Trotter, J. J. Chem. Soc. (A) 1967, 2024.21. O’Sullivan, K.; Thompson, R. C.; Trotter, J. I Chem. Soc. (A) 1970, 1814.22. Zemann, 3. Acta Crystallog. 1957, 10, 664.23. Zemann, 3. Acta Crystallog. 1960, 13, 863.24. Nord, A. G. Acta Ciystallog. 1976, B32, 664.25. Roziere, J.; Roziere-Boris, M.; Williams, J. M. Inorg. Chem.. 1976, 5, 2490.26. Strauss, S. H.; Abney, K. D.; Anderson, 0. P. Inorg. Chem. 1986, 25, 2806.27. Wells, A. F. Structural Inorganic Chemistry; 5th ed. Oxford University Press: Oxford,l984;p 1145.28. Jones, P. G. Gold Bull. 1986. 19, 46.29. Willner, H.; Rettig, S. J.; Trotter, J; Aubke, F. Can. J. Chem. 1991, 69, 391.30. Gamer, C. D.; Waliwork, S. C. J. Chem. Soc. (A) 1970, 3092.31. Mercier, H. P. A.; Sanders, J. C. P.; Schrobilgen, G. J. J. Am. Chem. Soc. 1994, 116, 2921.32. Hagen K.; Cross, V. R.; Hedberg, K. J. Mol. Struct. 1978, 44, 187.33. Lau, C; Lynton, H.; Passmore, J.; Siew, P.-Y. I Chem. Soc., Dalton Trans. 1973, 2535.34. Emsley, J. J. Chem. Soc. Rev. 1980, 9, 91.35. Macdonald, A. L.; Speakman, J. C. I Chem. Soc. Perldn II 1972, 825.36. Jones, P. G.; Sheidrick, G. M. Acta Crystallog. 1984, C40, 1776.37. Trömel, M.; Lupprich, E. Z. Anorg. Allg. Chem. 1975, 414, 160.38. Huheey, J. E.; Keiter, E. A.; Keiter, R. L. Inorganic Chemistry: Principles ofStructure andReactivity; Harper Collins College Publishers: New York, 4th ed., 1993; p 318.39. Cruickshank, D.W. 3. J. Chem. Soc. 1961, 5486.40. Bondi, A. J, Phys. Chem. 1964, 68, 441.146Chapter 6GENERAL CONCLUSIONS ANDSUGGESTIONS FOR FUTURE STUDIES6.1. General ConclusionsTwo types of conjugate superacids based on HSO3F are investigated by differentmethods in this study. A heteroleptic conjugate superacid, HSO3F/ bF5 (“Magic Acid”), isstudied by high resolution ‘9F 1D and 2D NMR (COSY and J-resolved). Twelve fluorofluorosulfato-antimonate(V) species are clearly identified. Based on the integration of the‘9F NMR signals due to fluorines bonded to antimony, relative concentrations of these speciesare estimated for systems with SbF5 concentration ranging from XSbF5 0.00 1 to X,F5 = 0.342,The 1:1 and 1:2 complexes between HSO3Fand SbF5, [SbF5( O3F)] and [Sb2F10(ji-SO3)f,are found to be the principal species in the system. Other constituent species includemonomers, [SbF6J, [SbF4( O3F)2jand [SbF3( OF)1, as well as dimers, [Sb2F11f,[Sb2F9(p-SO3)]and[Sb8Qt-SOF)( )]. In systems with XSbF5O.O989,trimers ofthe type [SbF5-Qi-SOF)-SbF(j are also observed. All oligomeric fluorofluorosulfato-antimonate(V) species are SO3F-bridged rather than F-bridged.Based on the relative concentrations of the species in the HSO3F/ bF5 system, itappears that solvolysis of SbF5 in HSO3F is likely to occur in addition to the ligandredistribution through P vs. SO3F exchange. The reaction of HF with Si02 in glasswareproduces H20, which is a strong base in conjugate superacid and therefore may reduce theacidity of the system. The oxonium salt [H30][Sb2F1J crystallizes from the HSO3F/ bF5system of high SbF5 content (xSbFS 0.342). The structure of [H3O][Sb2F1J is determined bysingle crystal X-ray diffraction. The distorted structure of [Sb2F1jJ ions is caused by thecation-anion interaction, via hydrogen bonding of the type O-H•F, in [H30][Sb2F]. Theoxonium ion H3O is observed in the ‘H NMR spectra of systems in low SbF5 concentration147range as well. The ‘H chemical shift due to H3O is dependent on the SbF5 concentration andH3O cannot be used as internal reference in the superacid media.Initial unsuccessful attempts to synthesize and isolate Sb(SO3F)5have resulted in aninvestigation of low valent antimony fluoro-fluorosulfato-derivatives. After an extensive studyof the reactions of antimony with fluorosulfuric acid andlor bis(fluorosulfuryl) peroxide, theexistence of the previously reported compounds, Sb(SO3F), Sb4(SO3F)2and Sb8(SO3F)2,isnot confirmed. Instead, two new Sb(III) compounds, [SbF2( O3F)J and [SbF(SO3F)21x, aswell as [Sb(SO3F)3]x, are obtained. Their polymeric structures are determined by singlecrystal X-ray diffraction.A detailed comparison for the series [SbFn(SO3F)3n1x (n = 0, 1, 2, or 3) provides aninsight into the complex coordination chemistry of Sb(III). In these fluoride fluorosulfates,fluoride functions as an asymmetrical bidentate bridging ligand and fluorosulfate functions asan 0-tridentate asymmetrical bridging ligands. The overall coordination number of antimonydepends on the available donor sites of the ligands and increases gradually from six for SbF3 tonine for [Sb(SO3F)]as F is sequentially replaced by SO3F. The highly distorted, irregularcoordination geometries cannot be explained by the VSEPR model.’ The Sb-O and Sb-Finteractions in all four compounds span a wide range from normal covalent bonds (1.9-2.1 A)to long secondary intermolecular contact ( 3.0 A), and present a complicated bonding. TheSb-O bonds may be described in terms of primary bonds (—2. 1 A), secondary bonds (‘-‘3.0 A)and intermediate bondsQ-’2.6 A).The relative weakness of intermediate bonds and secondary contacts is reflected in thefact that all three materials are soluble in HSO3F. The appreciable solubility of Sb(SO3F)seems to facilitate further oxidation of Sb(III) to Sb(V) to form, possibly, Sb(SO3F)5. As astarting point, the possible formation of anionic fluorosulfato-antimonate(V) complexes isstudied. If antimony is oxidized with S206F in the presence of an equalmolar amount ofCsSO3F, the salt Cs[Sb(SO3F)6]is obtained. Its structure is determined by single crystal X-ray148diffraction. The [Sb(SO3F)6]anion is highly symmetrical. Secondary contacts to Cs involveonly the oxygen atoms. The acidity of the hypothetical HSO3F/Sb(SO)5system is inferredfrom a structural study of superacid anions in the solid state.In order to compare the structure of [Sb(SO3F)6]to that of other superacid anions,single crystals of CsSO3F, Cs[H(SO3F)2],Cs[Au(SOF)41,and Cs2[Pt(SO3F)61are preparedand their molecular structures are determined by single crystal X-ray diffraction. Thestructures of the superacid anions are correlated to the weak nucleophilicity of anions andhence the acid strength of the corresponding conjugate superacids. For these symmetricalcomplex ions, strong bonding of the SO3F group to the central atom through a bridging oxygenatom results in lengthening of the corresponding S-O bond and shortening of the peripheral So and S-F bonds. The S-F bond lengths observed in [Sb(SO3F)6](1.486(3) A) is the shortestamong reported S-F bond length for anionic and neutral sulfur-oxygen-fluorine species.Appreciable pit—*dit bonding is suggested for both S-O and S-F bonds. Such bonding mayeffectively reduce the electron density on peripheral oxygen and fluorine atoms, and thereforecontribute to the weakening of nucleophilicity of the complex anions.6.2. Proposals for Further StudiesFrom the highly symmetrical structure and short, strong peripheral bonds of thesuperacid anion [Sb(SO3F)6],the anion is expected to be very weakly nucleophilic. The anionmay be used to stabilize highly electrophilic cations. If the corresponding Lewis acidSb(SO3F)5can be obtained and the conjugate superacid HSO3F/Sb(SO)5can be prepared,both should have a very interesting chemistry.Isolation of pure Sb(SO3F)5 is desirable. It is conceivable that Sb(SO3F) is anintermediate in the oxidation of antimony metal to Sb(SO3F)5. Therefore, it is possible tosynthesize Sb(SO3F)5by a two-step process:2Sb + 3S206F HSO3F 2Sb(SO3F) [6-1]149Sb(SO3F)+S206F S206F2 2Sb(SO3F) [6-2]If reaction [6-2] proceeds as expected, the use of excess S206F,instead of HSO3F, shouldfacilitate the isolation of pure Sb(SO3F)5. Its mixture with HSO3F should constitute a highlyacidic conjugate superacid.Alternatively, it is also possible to obtain the HSO3F/Sb(SO)5system by the in situoxidation of elemental metal by excess S206F in the presence of HSO3F. Two conjugatesuperacid systems, HSO3F/Ta(SO)5(solv) and HSO3F/Nb(SO)5(solv), were obtained in thismanner.2 The method should also be applicable to prepare HSO3F/Sb(SO)5(solv) conjugatesuperacid. The resulting HSO3F/Sb(SO)5csoIv) system can then be studied by aconductometric study and by the Hammett Acidity Function measurements.The detection of H3O in the HSO3F/ bF5 system (the “Magic acid”), and thesubsequent isolation and structure characterization of [H30j[Sb211, strongly suggests thepresence of HF as an intermediate, which will then react with glass. It is suggested thatfundamental studies of the “Magic acid” system (electrical conductivity measurements,H0 determinations, ‘9F NMR, vibrational spectroscopy) as well as many of the applications (thegeneration and study of inorganic cation and organic carbocations should be conducted inglass-free equipment (fluoropolymers and polymer-coatings of NMR tubes) to achieveconsiderably higher acidity of the “Magic Acid”.150References1. Gillespie, R.J., Hargittai, I. The VSEPR Model ofMolecular Geometry; Allyn and Bacon:Boston, 1991.2. Cicha, W. V.; Aubke, F. J. Am. Chem. Soc. 1988, 111, 4328.151AppendixA.FrequencyRangeofVibrationalBandsof theSO3FGroupinDifferentCoordinationModes.(AsymmetricalBi- andTndentatemodearenotincluded.Hetchedareasindicate“diagnosticbands”)‘BondingorFrequencyRange(cm1)coordination>-stretchingbandsdeformationbands‘movesVas(SO3)Vsym(SO3)v(S-F)Ip(SO3F)covalentIIItridentateas(S03)sym(SO3)EEJ> cv)C)Vas(S03)“sym(S03)v(S-F)as(S03)p(SO3F)Purelyy////ionicösym(S03)Vas(S02)(SO2)__V////iv(S0)v(S-F)(OSF)y(SO2F)ionicIIV///Aperturbedt(SO2F)Vsym(SO2)y(S02)v(S-O)8(S02)‘y(S02)y(SO2F)cYcovalentIV//////ArnmonodentateVas(S02)Vsyi(SO2)v(S-F)OSF)t(SO2F)Vas(S02)ö(S02)i(SO2)SO2F)t(SO2F)covalent1EJ0OEJEEJbidentatev(S-O)Vsym(S02)v(S-F)Y{OSF)140012001000800600400Appendix BElement Bond Length Valence Element Bond Length ValenceE dsb.E (A) VSbE E dsb.E (A) VSbE[SbF3] [SbF2( O3F)]F 1.90 0.955 F 1.896 0.9655F 1.94 0.857 F 2.828 0.0778F 1.94 0.857 F 1.927 0.8879F 2.63 0.133 F 2.687 0.1138F 2.60 0.144 0 2.946 0.0721F 2.60 0.144 0 2.342 0.3689V=3.09 V*=2.67 0 2.204 0.5356[SbF(SOF)j V=3.022 V*=2.7580 2.129 0.6560 [SbF(SO3F)2]0 2.55 0.2103 F 1.893 0.97330 2.642 0.1640 F 3.098 0.03750 2.112 0.6868 0 2.475 0.25750 2.834 0.0976 0 2.113 0.68500 2.615 0.1764 0 2.131 0.65240 2.052 0.8077 0 2.566 0.20140 3.009 0.0608 0 2.995 0.06320 2.977 0.0663 0 3.055 0.0537V=2.926 V*=2.151 V=2.924 V*=2.311Sb-E bond valence: VE =exp(RE- dsbE)/bwhere RSbF = 1.883 A, Rsb.o =1.973 A, b0.37 AValence of antimony:VSbE = VSb_EV*sb.E = VSb_E(all Sb-0 and Sb-F interatomic interaction are considered)(Only primary Sb-O and Sb-F bonds are considered)Calculated bond valence of Sb(III) in [SbF11( O3F)11(n=O,1,2,3).153Appendix CList of Crystallographic Data and Structure Parameters for [H301[Sb2FiiITable C-i Crystal Data.Empirical Formula F1H3OSb2Formula Weight 471.51Crystal Color, Habit colorless, prismCrystal Dimensions 0.30 x 0.30 x 0.35 mmCrystal System orthorhombicLattice Type PrimitiveNo. of Reflections Used for Unit Cell Determination (20) 25 ( 29.2 - 32.4°)Omega Scan Peak Width at Half-height 0.35°Lattice Parameters a = 12.744(2) Ab= 39.371(2)Ac= 11.407(3)AV= 5723(1) A3Space Group Pbca (#61)Z value 24Dcaic 3.283 g/cm3F000 5088.00p.(MoKa) 57.95 cm1Table C-2 Intensity Measurements.Diffractometer Rigaku AFC6SRadiation MoKcz (X = 0.71069 A) graphite monochromatedTake-off Angle 6.0°Detector Aperture 6.0 mm horizontal; 6.0 mm verticalCrystal to Detector Distance 285 mmTemperature 21.0°CScan TypeScan Rate 1 6.0°/mm (in 2) (up to 9 scans)Scan Width (0.82 + 0.35 tan0)°15429mw, 60.00No. of Reflections Measured Total: 9186CorrectionsLorentz-polarization Absorption trans. factors: 0.7000 - 1.0000Secondary Extinction coefficient: 1.17142 x 1 0Decay 3.22% declineTable C-3 Structure Solution and Refinement.Structure Solution Direct Methods (SHELXS86)Refinement Full-matrix least-squaresFunction Minimized w(IFoI - IFcI)2Least Squares Weights 1/2 (Fo) = 4Fo2/E (Fo2)p-factor 0.000Anomalous Dispersion All non-hydrogen atomsNo. Observations (I>3.00\sigma(I)) 4110No. Variables 380Reflection/Parameter Ratio 10.82Residuals: R; Rw 0.03 6 ; 0.032Goodness of Fit Indicator 2.13Max Shift/Error in Final Cycle 0.00Maximum peak in Final Diff. Map 1.11 e/A3Minimum peak in Final Diff. Map -0.96 e/A3Table C-4 Atomic coordinates and Beq.atom X Y Z BegSb(1) 0.46438(4) 0.05248(1) 0.13656(5) 3.86(1)Sb(2) 0.20221(5) 0.01976(2) 0.00068(6) 4.71(2)Sb(3) 0.50719(4) 0.18277(1) 0.10926(6) 3.77(1)Sb(4) 0.68504(5) 0.25490(2) -0.01397(6) 4.35(1)Sb(5) 0.38055(4) 0.12917(2) 0.48880(5) 3.85(1)Sb(6) 0.21358(5) 0.13366(2) 0.77216(5) 4.43(2)155atom X Y Z BeqF(1) 0.3388(4) 0.0239(1) 0.0883(5) 5.7(1)F(2) 0.5783(4) 0.0779(1) 0.1805(5) 6.6(2)F(3) 0.3796(5) 0.0890(1) 0.1119(8) 10.8(2)F(4) 0.4141(6) 0.0487(2) 0.2837(6) 11.1(3)F(S) 0.5286(4) 0.01 14(1) 0.1510(6) 7.8(2)F(6) 0.4997(5) 0.0528(2) -0.0163(5) 8.4(2)F(7) 0.0771(4) 0.0182(2) -0.0794(6) 9.0(2)F(8) 0.1734(5) 0.0620(2) 0.0612(7) 10.2(2)F(9) 0.1501(5) 0.0002(2) 0.1344(6) 10.6(2)F(10) 0.2503(5) -0.0220(2) -0.0440(7) 9.9(2)F(11) 0.2744(5) 0.0387(2) -0.1192(6) 9.8(2)F(12) 0.6317(4) 0.2113(1) 0.0567(5) 5.3(1)F(13) 0.3944(4) 0.1574(1) 0.1589(5) 5.7(1)F(14) 0.5851(5) 0.1752(2) 0.2414(6) 10.1(2)F(15) 0.4580(5) 0.2216(1) 0.1736(6) 8.0(2)F(16) 0.4480(4) 0.1948(2) -0.0290(5) 7.6(2)F(17) 0.5737(5) 0.1471(2) 0.0419(8) 10.5(2)F(18) 0.7304(4) 0.2950(1) -0.0790(5) 7.0(2)F(19) 0.5850(5) 0.2751(2) 0.0728(7) 10.2(2)F(20) 0.7761(5) 0.2555(2) 0.1099(5) 8.2(2)F(21) 0.7791(5) 0.2279(2) -0.0939(6) 8.4(2)F(22) 0.5886(5) 0.2463(2) -0.1289(6) 9.8(2)F(23) 0.2596(3) 0.1349(1) 0.6020(4) 4.9(1)F(24) 0.4932(4) 0.1233(1) 0.3883(5) 6.2(2)F(25) 0.3349(6) 0.1685(2) 0.4216(7) 11.0(3)F(26) 0.4523(5) 0.1539(2) 0.5946(6) 11.7(3)F(27) 0.4099(6) 0.0904(2) 0.5660(6) 11.1(2)F(28) 0.2883(5) 0.1071(2) 0.3954(6) 10.0(2)F(29) 0.1769(5) 0.1327(2) 0.9285(5) 8.2(2)F(30) 0.3029(5) 0.1702(2) 0.7903(5) 8.6(2)156atom x y z BegF(31) 0.1113(5) 0.1638(2) 0.7273(5) 9.2(2)F(32) 0.1327(6) 0.0986(2) 0.7319(7) 10.1(2)F(33) 0.3285(5) 0.1063(2) 0.7953(5) 7.6(2)0(1) 0.2031(4) 0.1231(1) 0.1731(5) 4.7(2)0(2) 0.4530(5) 0.0507(2) 0.7477(5) 5.1(2)0(3) 0.4455(5) 0.2139(1) 0.7462(5) 4.9(2)H(1) 0.2509 0.1339 0.1302 5.6820H(2) 0.1571 0.1381 0.2011 5.6820H(3) 0.1699 0.1080 0.1287 5.6820H(4) 0.4641 0.0292 0.7271 6.1700H(5) 0.5100 0.0629 0.7327 6.1700H(6) 0.4384 0.0516 0.8240 6.1700H(7) 0.4723 0.2040 0.6829 5.8610H(8) 0.3807 0.2063 0.7584 5.8610H(9) 0.4441 0.2363 0.7357 5.8610Beq = (8/3)t2U11(aa*)2+U22(bb*) +U33(cc*)2+ 2U12aa* bb*cosy + 2U13aa* cc*cosf +2U3bb* cc*cosoc)Table C-5 Anisotropic Displacement Parameters.atom U11 U22 U33 U12 U13 U23Sb(1) 0.0473(3) 0.0412(3) 0.0582(4) -0.0022(3) 0.0017(3) -0.0093(3)Sb(2) 0.0448(3) 0.0679(4) 0.0664(4) -0.0 102(3) 0.0007(3) 0.0048(4)Sb(3) 0.0419(3) 0.0409(3) 0.0605(4) -0.0020(3) -0.0033(3) 0.0101(3)Sb(4) 0.0475(3) 0.0523(4) 0.0653(4) -0.0111(3) -0.0009(3) 0.0075(3)Sb(5) 0.0391(3) 0.0678(4) 0.0393(3) 0.0034(3) 0.0024(3) -0.0022(3)Sb(6) 0.0542(4) 0.0656(4) 0.0486(4) 0.0047(3) 0.0121(3) 0.0081(3)F(1) 0.049(3) 0.052(3) 0.115(5) -0.008(3) -0.015(3) -0.005(3)F(2) 0.075(4) 0.084(4) 0.090(4) -0.033(3) -0.010(3) -0.015(4)F(3) 0.075(4) 0.041(3) 0.30(1) 0.012(3) -0.018(6) -0.017(5)F(4) 0.156(7) 0.174(7) 0.093(5) -0.071(6) 0.058(5) -0.049(5)F(S) 0.081(4) 0.058(3) 0.157(6) 0.013(3) -0.036(4) 0.005(4)157atom U11 U22 U33 U12 U13 U23F(6) 0.123(5) 0.137(6) 0.057(4) -0.046(5) 0.000(4) 0.002(4)F(7) 0.070(4) 0.156(7) 0.117(6) -0.022(4) -0.032(4) 0.023(5)F(8) 0.080(4) 0.101(5) 0.205(8) 0.033(4) -0.026(5) -0.071(6)F(9) 0.085(5) 0.220(9) 0.097(5) -0.053(5) 0.006(4) 0.061(6)F(10) 0.115(5) 0.091(5) 0.170(7) -0.008(5) -0.036(5) -0.035(5)F(11) 0.086(5) 0.172(7) 0.116(6) -0.014(5) 0.019(4) 0.064(5)F(12) 0.047(3) 0.060(3) 0.094(4) -0.003(3) 0.004(3) 0.026(3)F(13) 0.056(3) 0.061(3) 0.101(4) -0.016(3) 0.009(3) 0.01 1(3)F(14) 0.111(5) 0.142(6) 0.131(6) -0.045(5) -0.056(5) 0.089(5)F(15) 0.104(5) 0.067(4) 0.131(6) -0.019(4) 0.048(4) -0.035(4)F(16) 0.077(4) 0.149(6) 0.061(4) -0.029(4) -0.019(3) 0.025(4)F(17) 0.079(4) 0.062(4) 0.257(9) 0.007(4) 0.060(5) -0.012(5)F(18) 0.086(4) 0.070(4) 0.110(5) -0.023(3) 0.000(4) 0.035(4)F(19) 0.128(6) 0.068(4) 0.189(8) 0.008(4) 0.075(6) 0.021(5)F(20) 0.112(5) 0.102(5) 0.096(5) -0.044(4) -0.034(4) 0.019(4)F(21) 0.106(5) 0.088(5) 0.124(5) 0.000(4) 0.054(4) 0.001(4)F(22) 0.122(5) 0.111(5) 0.138(6) -0.059(5) -0.077(5) 0.055(5)F(23) 0.048(3) 0.094(4) 0.044(3) 0.0 12(3) 0.008(2) -0.002(3)F(24) 0.056(3) 0.113(5) 0.065(4) 0.012(3) 0.023(3) 0.009(3)F(25) 0.158(7) 0.125(6) 0.134(6) 0.067(6) 0.070(6) 0.048(5)F(26) 0.065(4) 0.248(9) 0.131(6) -0.050(5) 0.020(4) -0.112(7)F(27) 0.162(7) 0.152(7) 0.109(6) 0.097(6) 0.080(5) 0.078(5)F(28) 0.062(4) 0.205(8) 0.112(5) -0.021(5) 0.010(4) -0.086(6)F(29) 0.113(5) 0.146(6) 0.053(4) 0.030(5) 0.026(4) 0.028(4)F(30) 0.135(6) 0.102(5) 0.089(5) -0.055(4) 0.011(4) -0.020(4)F(31) 0.107(5) 0.158(7) 0.085(5) 0.077(5) 0.023(4) 0.019(5)F(32) 0.131(6) 0.125(6) 0.130(6) -0.059(5) 0.025(5) -0.005(5)F(33) 0.095(4) 0.118(5) 0.075(4) 0.044(4) 0.009(3) 0.030(4)158atom U11 U22 U33 U12 U13 U230(1) 0.039(3) 0.070(4) 0.071(4) 0.003(3) 0.000(3) -0.01 1(4)0(2) 0.073(4) 0.071(4) 0.051(4) 0.000(4) 0.012(3) 0.000(4)0(3) 0.068(4) 0.060(4) 0.05 8(4) -0.011(3) 0.004(3) 0.0 10(3)The general temperature factor expression:exp(2t2(a*2U11h2 + b*2U2k+ c*2U3312+ 2a*b*U12hk+2a*c*U13h1+ 2b*c*U3k1))Table C-6 Bond Lengths(A).atom atom distance atom atom distance atom atom distanceSb(1) F(1) 2.032(4) Sb(1) F(2) 1.834(5) Sb(1) F(3) 1.821(6)Sb(1) F(4) 1.803(6) Sb(1) F(S) 1.820(5) Sb(1) F(6) 1.801(6)Sb(2) F(1) 2.013(5) Sb(2) F(7) 1.839(6) Sb(2) F(9) 1.833(6)Sb(2) F(8) 1.839(6) Sb(2) F(10) 1.827(6) Sb(2) F(11) 1.808(6)Sb(3) F(12) 2.034(4) Sb(3) F(13) 1.839(5) Sb(3) F(14) 1.830(6)Sb(3) F(15) 1.809(5) Sb(3) F(16) 1.811(5) Sb(3) F(17) 1.811(6)Sb(4) F(12) 2.016(5) Sb(4) F(18) 1.839(5) Sb(4) F(19) 1.799(6)Sb(4) F(20) 1.829(6) Sb(4) F(21) 1.842(6) Sb(4) F(22) 1.829(6)Sb(S) F(23) 2.023(4) Sb(S) F(24) 1.852(5) Sb(S) F(25) 1.824(7)Sb(5) F(26) 1.799(6) Sb(S) F(27) 1.802(6) Sb(S) F(28) 1.810(6)Sb(6) F(23) 2.028(4) Sb(6) F(29) 1.845(5) Sb(6) F(30) 1.846(6)Sb(6) F(31) 1.835(6) Sb(6) F(32) 1.785(7) Sb(6) F(33) 1.838(6)0(1) H(1) 0.89 0(1) H(2) 0.89 0(1) H(3) 0.890(2) H(4) 0.89 0(2) H(S) 0.89 0(2) H(6) 0.89Table C-7 Bond Angles (°).atom atom atom angle atom atom atom angleF(1) Sb(1) F(2) 179.5(2) F(1) Sb(1) F(3) 8S.9(2)F(1) Sb(1) F(4) 85.8(3) F(1) Sb(1) F(S) 83.5(2)F(1) Sb(1) F(6) 86.4(3) F(2) Sb(1) F(3) 94.6(3)F(2) Sb(1) F(4) 94.1(3) F(2) Sb(1) F(S) 96.0(3)159atom atom atom angle atom atom atom angleF(2) Sb(1) F(6) 93.6(3) F(3) Sb(1) F(4) 89.9(4)F(3) Sb(1) F(5) 169.4(3) F(3) Sb(1) F(6) 89.6(4)F(4) Sb(1) F(S) 90.1(4) F(4) Sb(1) F(6) 172.2(3)F(5) Sb(1) F(6) 88.9(3) F(1) Sb(2) F(7) 177.3(3)F(1) Sb(2) F(8) 85.0(2) F(1) Sb(2) F(9) 86.2(2)F(1) Sb(2) F(10) 85.5(2) F(1) Sb(2) F(11) 84.4(3)F(7) Sb(2) F(8) 92.5(3) F(7) Sb(2) F(9) 94.9(3)F(7) Sb(2) F(10) 97.0(3) F(7) Sb(2) F(11) 94.6(3)F(8) Sb(2) F(9) 89.7(4) F(8) Sb(2) F(10) 170.4(3)F(8) Sb(2) F(11) 90.8(4) F(9) Sb(2) F(10) 88.6(4)F(9) Sb(2) F(11) 170.5(3) F(10) Sb(2) F(11) 89.3(4)F(12) Sb(3) F(13) 179.1(2) F(12) Sb(3) F(14) 84.8(2)F(12) Sb(3) F(15) 85.6(2) F(12) Sb(3) F(16) 85.7(2)F(12) Sb(3) F(17) 86.4(2) F(13) Sb(3) F(14) 94.7(3)F(13) Sb(3) F(15) 93.6(2) F(13) Sb(3) F(16) 94.8(2)F(13) Sb(3) F(17) 94.3(3) F(14) Sb(3) F(15) 89.6(3)F(14) Sb(3) F(16) 170.4(3) F(14) Sb(3) F(17) 88.2(4)F(15) Sb(3) F(16) 89.3(3) F(15) Sb(3) F(17) 171.9(3)F(16) Sb(3) F(17) 91.6(4) F(12) Sb(4) F(18) 178.6(2)F(12) Sb(4) F(19) 85.3(2) F(12) Sb(4) F(20) 85.2(2)F(12) Sb(4) F(21) 85.8(2) F(12) Sb(4) F(22) 84.4(2)F(18) Sb(4) F(19) 93.8(3) F(18) Sb(4) F(20) 95.8(3)F(18) Sb(4) F(21) 95.2(3) F(18) Sb(4) F(22) 94.7(3)F(19) Sb(4) F(20) 91.1(4) F(19) Sb(4) F(21) 171.0(3)F(19) Sb(4) F(22) 90.0(4) F(20) Sb(4) F(21) 88.7(3)F(20) Sb(4) F(22) 169.4(3) F(21) Sb(4) F(22) 88.6(3)F(23) Sb(S) F(24) 178.4(2) F(23) Sb(5) F(25) 86.0(3)F(23) Sb(S) F(26) 84.2(2) F(23) Sb(S) F(27) 86.6(2)F(23) Sb(S) F(28) 86.2(2) F(24) Sb(S) F(25) 95.4(3)F(24) Sb(S) F(26) 95.1(3) F(24) Sb(S) F(27) 92.0(3)F(24) Sb(S) F(28) 94.5(3) F(25) Sb(S) F(26) 89.1(4)160atom atom atom angle atom atom atom angleF(25) Sb(5) F(27) 172.5(3) F(25) Sb(5) F(28) 87.4(4)F(26) Sb(S) F(27) 91.4(4) F(26) Sb(5) F(28) 170.0(3)F(27) Sb(S) F(28) 90.9(4) F(23) Sb(6) F(29) 177.9(2)F(23) Sb(6) F(30) 84.9(2) F(23) Sb(6) F(31) 85.6(2)F(23) Sb(6) F(32) 86.5(3) F(23) Sb(6) F(33) 85.5(2)F(29) Sb(6) F(30) 93.7(3) F(29) Sb(6) F(31) 95.9(3)F(29) Sb(6) F(32) 95.0(3) F(29) Sb(6) F(33) 92.9(3)F(30) Sb(6) F(31) 88.0(3) F(30) Sb(6) F(32) 171.4(3)F(30) Sb(6) F(33) 87.1(3) F(31) Sb(6) F(32) 91.0(4)F(31) Sb(6) F(33) 170.2(3) F(32) Sb(6) F(33) 92.5(3)Sb(1) F(1) Sb(2) 149.4(3) Sb(3) F(12) Sb(4) 148.3(3)Sb(S) F(23) Sb(6) 145.9(2)H(1) 0(1) H(2) 109.5 H(1) 0(1) H(3) 109.5H(2) 0(1) H(3) 109.5 H(4) 0(2) H(S) 109.6H(4) 0(2) H(6) 109.5 H(S) 0(2) H(6) 109.5H(7) 0(3) H(8) 109.S H(7) 0(3) H(9) 109.5H(S) 0(3) H(9) 109.6 0(1) H(1) F(13) 136.80(1) H(1) F(3) 99.3 0(1) H(1) F(29) 103.9F(13) H(1) F(3) 75.1 F(13) H(1) F(29) 119.3F(3) H(1) F(29) 99.4 0(1.) H(2) F(14) 168.00(1) H(2) F(24) 105.1 F(14) H(2) F(24) 84.90(1) H(3) F(8) 146.0 0(1) H(3) F(24) 109.40(1) H(3) F(29) 104.1 F(8) H(3) F(24) 103.1F(8) H(3) F(29) 90.0 F(24) H(3) F(29) 81.80(2) H(4) F(S) 123.3 0(2) H(4) F(9) 122.40(2) H(4) F(7) 118.8 F(S) H(4) F(9) 86.9F(S) H(4) F(7) 108.5 F(9) H(4) F(7) 87.80(2) H(S) F(32) 156.6 0(2) H(6) F(6) 144.80(2) H(6) F(11) 117.8 F(6) H(6) F(11) 96.1161atom atom atom angle atom atom atom angle0(3) H(7) F(19) 125.5 0(3) H(7) F(26) 135.4F(19) H(7) F(26) 99.1 0(3) H(8) F(30) 145.20(3) H(8) F(21) 104.9 F(30) H(8) F(21) 98.20(3) H(9) F(15) 163.2 0(3) H(9) F(22) 93.4F(15) H(9) F(22) 91.6Table C-S. Torsion Angles(°).atom atom atom atom angle atom atom atom atom angleSb(1) F(1) Sb(2) F(8) -43.2(6) Sb(1) F(1) Sb(2) F(9) -133.2(7)Sb(1) F(1) Sb(2) F(10) 137.8(6) Sb(1) F(1) Sb(2) F(11) 48.1(6)Sb(2) F(1) Sb(1) F(3) 24.3(6) Sb(2) F(1) Sb(1) F(4) 114.5(6)Sb(2) F(1) Sb(1) F(5) -154.9(6) Sb(2) F(1) Sb(1) F(6) -65.6(6)Sb(3) F(12) Sb(4) F(19) 39.9(6) Sb(3) F(12) Sb(4) F(20) 131.4(6)Sb(3) F(12) Sb(4) F(21) -139.5(6) Sb(3) F(12) Sb(4) F(22) -50.5(6)Sb(4) F(12) Sb(3) F(14) -134.0(6) Sb(4) F(12) Sb(3) F(15) -44.0(6)Sb(4) F(12) Sb(3) F(16) 45.6(6) Sb(4) F(12) Sb(3) F(17) 137.5(6)Sb(S) F(23) Sb(6) F(30) 64.7(5) Sb(S) F(23) Sb(6) F(31) 153.2(6)Sb(S) F(23) Sb(6) F(32) -115.5(6) Sb(5) F(23) Sb(6) F(33) -22.8(5)Sb(6) F(23) Sb(5) F(25) -133.8(6) Sb(6) F(23) Sb(S) F(26) -44.3(6)Sb(6) F(23) Sb(S) F(27) 47.4(6) Sb(6) F(23) Sb(5) F(28) 138.5(6)Table C-9. Non-bonded Contacts out to 3.60 A.atom atom distance ADC atom atom distance ADCF(1) F(S) 3.499(8) 65505 F(2) 0(1) 2.913(8) 8F(2) F(28) 3.037(8) 8 F(2) F(17) 3.149(9) 1F(2) F(24) 3.158(8) 1 F(2) F(8) 3.247(10) 8F(2) F(10) 3.471(9) 65505 F(3) 0(1) 2.71 1(8) 1F(3) F(13) 2.752(7) 1 F(3) F(17) 3.462(9) 1F(3) F(28) 3.51(1) 1 F(4) F(10) 3.059(9) 4162atom atom distance ADC atom atom distance ADCF(4) F(7) 3.06(1) 4 F(4) F(28) 3.08(1) 1F(4) F(24) 3.325(9) 1 F(S) 0(2) 2.713(8) 65605F(S) F(9) 2.930(9) 8 F(S) F(6) 2.980(9) 65505F(S) F(10) 3.098(10) 65505 F(S) F(11) 3.213(9) 6550SF(S) F(7) 3.553(9) 4 F(6) 0(2) 2.758(8) 55401F(6) F(10) 3.48(1) 65505 F(6) F(32) 3.488(9) 8F(7) 0(2) 2.797(9) 45508 F(7) F(7) 3.03(1) 5F(7) F(9) 3.049(8) 5 F(7) F(27) 3.557(9) 45508F(8) 0(1) 2.750(8) 1 F(8) F(29) 3.167(10) 55401F(8) F(24) 3.379(8) 45508 F(9) 0(2) 2.722(9) 55404F(9) F(11) 3.342(10) 4 F(10) F(28) 3.46(1) 55404F(11) 0(2) 2.777(8) 55401 F(11) F(33) 2.917(9) 55401F(11) F(32) 3.42(1) 55401 F(12) F(25) 3.098(8) 8F(13) 0(1) 2.791(7) 1 F(13) F(18) 2.950(7) 4SS02F(13) F(25) 3.122(9) 1 F(13) F(24) 3.200(8) 1F(14) 0(1) 2.722(9) 8 F(14) F(24) 2.890(8) 1F(14) F(18) 3.000(9) 7 F(14) F(22) 3.43(1) 7F(15) 0(3) 2.674(7) 55407 F(15) F(22) 3.073(9) 7F(15) F(21) 3.156(9) 45502 F(15) F(18) 3.163(9) 45502F(16) 0(3) 2.672(8) S5401 F(16) F(30) 2.934(8) 55401F(16) F(18) 3.060(8) 45502 F(16) F(20) 3.077(9) 45502F(16) F(31) 3.308(9) 8 F(17) F(23) 2.922(8) 8F(17) F(31) 3.18(1) 8 F(17) F(28) 3.237(9) 8F(17) F(2S) 3.46(1) 8 F(18) F(29) 3.393(9) 55602F(18) 0(1) 3.414(8) 2 F(19) 0(3) 2.695(9) 55407F(19) F(26) 3.28(1) 55407 F(19) F(31) 3.33(1) 55602F(19) F(22) 3.51(1) 7 F(20) 0(3) 2.967(8) 55602F(20) F(30) 3.157(9) 55602 F(20) F(21) 3.441(9) 7F(20) F(25) 3.525(10) 8 F(21) 0(3) 2.797(8) 8F(21) F(2S) 3.14(1) 8 F(21) F(30) 3.207(9) 8163atom atom distance ADC atom atom distance ADCF(22) 0(3) 2.641(8) 55401 F(22) F(31) 3.45(1) 8F(24) 0(1) 2.765(7) 8 F(24) F(29) 3.159(8) 55608F(26) F(31) 2.897(9) 55608 F(26) 0(3) 2.931(9) 1F(26) F(29) 2.993(9) 55608 F(27) 0(2) 2.654(9) 1F(28) 0(1) 2.830(10) 1 F(29) 0(1) 2.835(8) 55601F(30) 0(3) 2.553(8) 1 F(31) 0(3) 2.907(8) 45608F(32) 0(2) 2.976(9) 45608 F(33) 0(2) 2.757(8) 1F(2) H(3) 2.74 8 F(2) H(2) 2.90 8F(3) H(1) 2.42 1 F(3) H(3) 2.78 1F(S) H(4) 2.12 65605 F(S) H(6) 2.53 6S605F(6) H(6) 1.98 55401 F(6) H(S) 2.89 55401F(7) H(4) 2.26 4SS08 F(7) H(S) 2.63 45508F(8) H(3) 1.97 1 F(9) H(4) 2.14 55404F(11) H(6) 2.25 55401 F(13) H(1) 2.07 1F(14) H(2) 1.85 8 F(15) H(9) 1.81 55407F(15) H(7) 2.94 55407 F(16) H(8) 2.61 55401F(18) H(1) 2.87 2 F(19) H(7) 2.08 55407F(19) H(9) 2.62 55407 F(20) H(8) 2.51 55602F(20) H(9) 2.79 55602 F(21) H(8) 2.43 8F(21) H(9) 2.67 8 F(21) H(7) 2.83 8F(22) H(9) 2.43 55401 F(24) H(3) 2.34 8F(24) H(2) 2.40 8 F(26) H(7) 2.23 1F(26) H(8) 2.93 1 F(27) H(S) 2.53 1F(29) H(3) 2.48 55601 F(29) H(1) 2.49 S5601F(30) H(8) 1.77 1 F(30) H(7) 2.82 1F(31) H(7) 2.59 45608 F(32) H(S) 2.14 45608F(33) H(6) 2.59 1 F(33) H(S) 2.96 1164The ADC (atom designator code) specifies the position of anatom in a crystal. The 5-digitnumber shown in the table isa composite of three one-digit numbers and one two-digitnumber:TA (first digit) + TB (second digit) + TC (thirddigit) + SN (last two digits). TA, TB and TCare the crystallattice translation digits along cell edges a, b and c.A translation digit of 5indicates the origin unit cell.If TA = 4, this indicates a translation of one unit celllength alongthe a-axis in the negative direction. Eachtranslation digit can range in value from 1 to 9 andthus±4 lattice translations from the origin (TA=5,TB=5, TC5) can be represented.The SN, or symmetry operator number, refers to the numberof the symmetry operator used togenerate the coordinatesof the target atom. A list of symmetry operators relevantto thisstructure are given below.For a given intermolecular contact, the first atom (originatom) islocated in the origin unit cell and its positioncan be generated using the identity operator(SN=1). Thus,the ADC for an origin atom is always 55501. The positionof the second atom(target atom) can be generated usingthe ADC and the coordinates of the atom in theparametertable. For example, an ADC of 47502 refers to the targetatom moved throughsymmetry operator two, then translated-i cell translations along the a axis, +2 celltranslationsalong the b axis, and 0 cell translations along the c axis.An ADC of 1 indicates anintermolecular contact between twofragments (eg. cation and anion) that reside in thesameasymmetric unit.Symmetry Operators:(1) X, Y, Z (2) 1/2+X, 1/2-Y, -z(3) -X, 1/2+Y, 1/2-Z (4) 1/2-X, -Y, 1/2+Z(5) -X, -Y, -z (6) 1/2-X, 1/2+Y,Z(7) X, 1/2-Y, i/2+Z (8) i/2+X, Y, 1/2-Z165Appendix DList of Crystallographic Data and Structure Parameters for ISbF2( O3F)1,ISbF(SO3F)21,and ISb(SO3F)1.Table D-1. Crystal Data.Compound [SbF2( O3F)] [SbF(SO3F)2J [Sb(SO3F)]Empirical Formula F3OSSb F3O6S2b F3O9SbFormula Weight 258.80 338.86 418.92Crystal Color, Habit colorless, prism colorless, prism colorless, prismCrystal Dimensions (mm) 0.30x0.30x0.30 0.25x0.40x0.40 0.20 x 0.25x0.40Crystal System orthorhombic monoclinic hexagonalLattice Type Primitive Primitive PrimitiveNo. of Reflections Used 25 25 25for Unit Cell Determination (57.159.80) (68.5-69.7°) (50.7-59.1°)(29 range)Omega Scan Peak Width 0.34° 0.37° 0.37°at_Half-heightLattice Parameters a= 13.403 5(6)A a=1 0.7302(8)A a=9.57 1 8(9)Ab=7.1852(6)A b=4.899(1)Ac=5.0239(9)A c=13.671(1)A c=17.283(1)Af3=1 11 .253(7)°V=483.8( 1)A3 V=669.7(3)A V=137 1 .3(3)ASpace Group Pna21 (#33) P21/c (#14) P65 (#170)Zvalue 4 4 6Dcaic 3.553 g/cm3 3.361 g cm3 3.043 g/cm3F000 472 632 1188i(Mo-Kcc) 61.40 cnr1 47.96 cm1 37.85 cnr’Table D-2. Intensity MeasurementsCompound [SbF2( O3F)j [SbF(SO3F)2J [SbF(SO3F)]Diffractometer Rigaku AFC6SRadiation Mo-Ka (. = 0.7 1069 A) graphite monochromatedTake-off Angle 6.0°166Detector Aperture 6.0 mm horizontal; 6.0 mm verticalCrystal to Detector 28.5 cmDistanceTemperature 21.0°CScan Type 2-29Scan Rate 32.0°/mm (in 2) 32.0°/mm (in 2) 32°/mm (in 2(8 rescans) (8 rescans) (up to 9 scans)Scan Width (1.31 + 0.35 tanO)° (1.63 + 0.35tan O)° (1.42 + 0.35 tanO)°2em, 100° 100.1° 100°No. of Reflections Total: 2905 Total: 7745, Total: 5441;Measured Unique: 7003 Unique: 4926(Rmt = 0.02 1) (R11t= 0.032)CorrectionsLorentz-polarization trans. factors: trans. factors: trans. factors:Absorption 0.84 - 1.00 0.54 - 1.00 0.809 - 1.000Secondary Extinction coefficient: coefficient:2.93(3) x105 0.296(11) x 10.6Decay (10.4% decline)Table D-3. Structure Solution and RefinementCompound [SbFz(SO3F)] [SbF(SO3F)2] [Sb(SO3F)]Structure Solution Direct Methods Direct Methods(S1R88) (S1R92)Refinement Full-matrix least-squaresFunction Minimized Z w (IFol - IFcI)2Least Squares Weights l/a2(Fo)=4Fo/Fo)p-factor 0.00Anomalous Dispersion All non-hydrogen atomsNo. Observations (I>3a(I)) 1807 4572 2675No. Variables 73 110 144Reflection/Parameter Ratio 24.75 41.56 18.6Residuals: R; Rw 0.025 ; 0.026 0.028 ; 0.027 0.030 ; 0.027Goodness of Fit Indicator 1.34 1.86 1.39167Max Shift/Error in Final Cycle 0.0009 0.10 0.0003Maximum peak in Final Diff. Map 1.38 e/A3 0.72 ek3 1.22 e/A3Minimum peak in Final Diff. Map -1.11 e/A3 -0.68 ek3 -1.23 e/A3Table D-4 Atomic coordinates and Beq.atom x y z Beq[SbF2( O3F)JSb(1) 0.71090(1) 0.21402(2) 0.8137 1.485(2)S(1) 0.45037(5) 0.2256(1) 0.6064(2) 1.73(1)F(1) 0.4461(3) 0.3085(4) 0.326(1) 5.65(9)F(2) 0.6973(2) 0.0281(4) 0.5485(6) 2.89(5)F(3) 0.7240(2) 0.3954(4) 0.5335(6) 2.83(5)0(1) 0.4350(2) 0.0332(4) 0.5735(7) 2.41(5)0(2) 0.5449(2) 0.2854(4) 0.710(1) 3.51(7)0(3) 0.3716(2) 0.3274(5) 0.7413(8) 3.46(7)[SbF(SO3F)2JSb(1) 0.248637(11) 0.0.13796(3) 0.241477(9) 1.470(3)S(1) 0.0.57252(4) 0.0.24031(10) 0.38861(3) 1.38(1)S(2) 0.08697(4) 0.33616(11) 0.40414(3) 1.48(1)F(1) 0.25221(12) -0.2368(3) 0.27610(1 1) 2.07(4)F(2) 0.61238(13) 0.3524(3) 0.50090(10) 2.66(5)F(3) -0.00097(14) 0.0883(3) 0.40533(12) 2.86(5)0(1) 0.43215(14) 0.1646(4) 0.36963(12) 2.32(5)0(2) 0.57961(15) 0.4693(4) 0.32515(12) 2.19(5)0(3) 0.6589(2) 0.0191(4) 0.39564(14) 2.75(6)0(4) 0.19217(14) 0.2111(4) 0.37341(12) 2.24(5)0(5) 0.00027(14) 0.5118(4) 0.32445(11) 2.09(5)0(6) 0.13756(14) 0.4364(4) 0.50816(11) 2.33(5)168atom x y z Beq[Sb(SO3F)]Sb(1) 0.61969(3) 0.36227(3) 0.3712 1.642(4)S(1) 0.4012(1) 0.3144(1) 0.21052(6) 1.55(1)S(2) 0.6125(1) 0.7171(1) 0.36511(7) 1.62(1)S(3) 0.4073(1) 0.3153(1) 0.53117(7) 2.09(2)F(1) 0.2404(3) 0.1542(4) 0.2107(2) 4.26(7)F(2) 0.7872(3) 0.8491(4) 0.3484(2) 3.58(6)F(3) 0.2248(4) 0.1993(5) 0.5346(3) 4.62(7)0(1) 0.4361(3) 0.3405(4) 0.2942(2) 1.82(5)0(2) 0.3639(4) 0.4278(5) 0.1777(2) 2.63(7)0(3) 0.5117(4) 0.2853(4) 0.1690(2) 2.32(6)0(4) 0.6365(4) 0.5866(4) 0.3952(2) 2.22(6)0(5) 0.5323(4) 0.6837(4) 0.2932(2) 2.69(7)0(6) 0.5613(4) 0.7828(4) 0.4251(2) 2.40(6)0(7) 0.4350(3) 0.2805(3) 0.4500(2) 2.04(5)0(8) 0.4768(5) 0.2580(4) 0.5860(2) 3.18(7)0(9) 0.4309(5) 0.4716(4) 0.5404(2) 3.19(7)For [SbF2( 03F)1: Beq = (8/3)it2{U11(aa*)2+U22(bb*) +U33(bb*)2+2Uiaa*bb*cosy+2Uiaa*cc*cosf3 +2U3bb*cc*cosx)For [SbF(S03F)2J: Beq = (8/3)1cZEU(a*a*)(aa)For [Sb(S03F)1: Beq = (8/3)1t2U11aa*) + U22 (bb*)2 + U33 (cc*)2 + 2U12aa* bb*cos y+2U13aa* cccos 3 + 2U3 bb*cc*coscx)Table D-5 Bond Lengths(A)atom atom distance atom atom distance[SbF2( 03F)]Sb(1) F(2) 1.896(3) Sb(1) F(2) 2.828(3)Sb(1) F(3) 1.927(3) Sb(1) F(3)b 2.687(2)Sb(1) 0(2) 2.342(3) Sb(1) 0(3)° 2.204(3)169atom atom distance atom atom distanceS(1) F(1) 1.529(6) S(1) 0(1) 1.408(3)S(1) 0(2) 1.435(3) S(1) 0(3) 1.453(3)[SbF(S03F)2JSb(1) F(1) 1.893(1) S(1) F(2) 1.538(1)Sb(1) 0(1) 2.113(1) S(1) 0(1) 1.480(1)Sb(1) 0(2)1 2.475(2) S(1) 0(2) 1.437(2)Sb(1) O(3) 3.055(2) S(1) 0(3) 1.407(2)Sb(1) F(1) 3.098(2) S(2) F(3) 1.542(2)Sb(1) 0(4) 2.131(1) S(2) 0(4) 1.473(1)Sb(1) 0(5)2 2.566(1) S(2) 0(5) 1.435(2)Sb(1) 0(6) 2.995(2) S(2) 0(6) 1.414(2)[Sb(S03F)]Sb(1) 0(1) 2.129(3) Sb(1) 0(2)i 2.550(3)Sb(1) 0(3)ii 2.642(3) Sb(1) 0(4) 2.112(3)Sb(1) 0(5)i 2.834(3) Sb(1) 0(6)iii 2.615(3)Sb(1) 0(7) 2.052(3) Sb(1) 0(8)iv 3.009(4)Sb(1) 0(9)iii 2.977(3) S(1) F(1) 1.536(3)S(1) 0(1) 1.477(3) S(1) 0(2) 1.419(3)S(1) 0(3) 1.417(3) S(2) F(2) 1.537(3)S(2) 0(4) 1.474(3) S(2) 0(5) 1.412(3)S(2) 0(6) 1.421(3) S(3) F(3) 1.533(3)S(3) 0(7) 1.496(3) S(3) 0(8) 1.417(3)S(3) 0(9) 1.407(3)170Table D-6 Bond Angles(°)*atom atom atom angle atom atom atom angle[SbF2( 03F)1F(2) Sb(1) F(2) 153.8(1) F(2) Sb(1) F(3) 88.4(2)F(2) Sb(1) F(3)b 73.7(1) F(2) Sb(1) 0(2) 84.7(1)F(2) Sb(1) O(3)C 83.3(1) F(2) Sb(1) F(3) 74.1(1)F(2) Sb(1) F(3)b 111.54(10) F(2) Sb(1) 0(2) 109.35(9)F(2) Sb(1) 0(3) 75.6(1) F(3) Sb(1) F(3)b 147.9(1)F(3) Sb(1) 0(2) 77.1(1) F(3) Sb(1) 0(3)C 83.2(1)F(3)b Sb(1) 0(2) 125.89(9) F(3)b Sb(1) 0(3)C 68.62(9)0(2) Sb(1) 0(3)C 157.1(2) F(1) S(1) 0(1) 105.6(2)F(1) S(1) 0(2) 104.5(3) F(1) S(1) 0(3) 101.9(2)0(1) S(1) 0(2) 117.8(1) 0(1) S(1) 0(3) 116.3(2)0(2) S(1) 0(3) 108.7(2) Sb(1) F(2) Sb(1)d 144.5(1)Sb(1) F(3) Sb(1) 155.0(1) Sb(1) 0(2) S(1) 148.6(2)Sb(1)f 0(3) S(1) 136.0(2)[SbF(S03F)2]F(1) Sb(1) 0(1) 85.66(6) F(1) Sb(1) 0(2)1 79.52(6)F(1) Sb(1) O(3) 139.87(5) F(1) Sb(1) 0(4) 86.43(7)F(1) Sb(1) 0(5)2 77.20(5) F(1) Sb(1) 0(6) 96.47(5)F(1) Sb(1) F(1)5 157.35(7) 0(1) Sb(1) 0(2)1 74.41(5)0(1) Sb(1) 0(3) 93.36(5) 0(1) Sb(1) 0(4) 75.71(6)0(1) Sb(1) 0(5)2 147.66(5) 0(1) Sb(1) 0(6) 141.46(5)0(1) Sb(1) F(1)5 81.72(6) 0(2)’ Sb(1) 0(3) 61.80(6)0(2)1 Sb(1) 0(4) 147.75(5) 0(2)’ Sb(1) 0(5)2 127.56(5)0(2)’ Sb(1) 0(6) 68.25(5) 0(2)’ Sb(1) F(1)5 114.63(5)0(4) Sb(1) 0(3) 132.21(6) 0(4) Sb(1) 0(5)2 76.04(5)0(4) Sb(1) 0(6) 142.78(5) 0(4) Sb(1) F(1)5 72.30(6)0(5)2 Sb(1) 0(3) 117.38(5) 0(5)2 Sb(1) 0(6) 68.58(4)0(5)2 Sb(1) F(1)5 104.21(4) 0(6) Sb(1) 0(3) 60.87(5)0(6) Sb(1) F(1)5 105.13(5) 0(3) Sb(1) F(1)5 60.04(4)171F(2) S(1) 0(1) 99.30(8) F(3) S(2) 0(4) 102.2(1)F(2) S(1) 0(2) 105.5(1) F(3) S(2) 0(5) 104.45(9)F(2) S(1) 0(3) 105.6(1) F(3) S(2) 0(6) 106.0(1)0(1) S(1) 0(2) 111.3(1) 0(4) S(2) 0(5) 112.7(1)atom atom atom angle atom atom atom angle0(1) S(1) 0(3) 115.0(1) 0(4) S(2) 0(6) 112.13(9)0(2) S(1) 0(3) 117.7(1) 0(5) S(2) 0(6) 117.5(1)Sb(1) 0(1) S(1) 138.1(1) Sb(1) 0(4) S(2) 142.5(1)Sb(1)4 0(2) S(1) 133.8(1) Sb(1)7 0(5) S(2) 135.8(1)Sb(1)’ 0(3) S(1) 141.4(1) Sb(1)8 0(6) S(2) 152.7(1)Sb(1) F(1) Sb(1)6 157.35(7)[Sb(S03F)j0(1) Sb(1) 0(2)1 71.3(1) 0(1) Sb(1) O(3)ii 145.6(1)0(1) Sb(1) 0(4) 82.1(1) 0(1) Sb(1) 0(5)i 136.9(1)0(1) Sb(1) O(6)iii 75.9(1) 0(1) Sb(1) 0(7) 82.3(1)0(1) Sb(1) O(8)iv 91.2(1) 0(1) Sb(1) O(9)iii 142.0(1)O(2)i Sb(i) O(3)ii 126.3(1) O(2)i Sb(1) 0(4) 145.1(1)0(2)1 Sb(1) O(5)i 65.9(1) O(2)i Sb(1) O(6)iii 120.77(10)0(2)1 Sb(1) 0(7) 72.1(1) O(2)i Sb(1) O(8)iv 65.9(1)O(2)i Sb(1) O(9)iii 110.2(1) O(3)ii Sb(1) 0(4) 68.0(1)O(3)ii Sb(1) O(5)i 65.90(10) O(3)ii Sb(1) O(6)iii 108.6(1)O(3)ii Sb(1) 0(7) 77.4(1) O(3)ii Sb(1) 0(8)iv 122.46(9)O(3)ii Sb(1) O(9)iii 65.71(10) 0(4) Sb(1) 0(5)1 133.1(1)0(4) Sb(1) O(6)iii 71.7(1) 0(4) Sb(1) 0(7) 82.5(1)0(4) Sb(1) 0(8)i’ 138.4(1) 0(4) Sb(1) O(9)iii 104.7(1)0(5)1 Sb(1) 0(6)iii 131.88(9) O(5)i Sb(1) 0(7) 79.7(1)O(5)i Sb(1) O(8)iv 76.8(1) O(5)i Sb(1) (J(9)iii 63.1(1)O(6)iii Sb(1) 0(7) 148.1(1) O(6)iii Sb(1) O(8)iV 66.94(10)O(6)iii Sb(1) O(9)iii 71.2(1) 0(7) Sb(1) 0(8)iV 137.3(1)0(7) Sb(1) O(9)iii 135.3(1) O(8)iv Sb(1) O(9)iii 58.67(10)F(1) S(1) 0(1) 101.3(2) F(1) S(1) 0(2) 104.8(2)172atom atom atom angle atom atomatom angleF(1) S(1) 0(3) 106.2(2) 0(1) S(1) 0(2) 112.6(2)0(1) S(1) 0(3) 113.7(2) 0(2) S(1) 0(3) 116.5(2)F(2) S(2) 0(4) 101.3(2) F(2) S(2) 0(5) 105.4(2)F(2) S(2) 0(6) 104.3(2) 0(4) S(2) 0(5) 114.6(2)0(4) S(2) 0(6) 110.6(2) 0(5) S(2) 0(6) 118.3(2)F(3) S(3) 0(7) 98.1(2) F(3) S(3) 0(8) 106.2(2)F(3) S(3) 0(9) 106.5(2) 0(7) S(3) 0(8) 111.8(2)0(7) S(3) 0(9) 113.0(2) 0(8) S(3) 0(9) 118.6(2)Sb(1) 0(1) S(1) 137.2(2) Sb(1)V 0(2) S(1) 145.3(2)Sb(1)iV 0(3) S(1) 151.4(2) Sb(1) 0(4) S(2) 145.8(2)Sb(1)V 0(5) S(2) 150.0(2) Sb(1)Vi 0(6) S(2) 149.9(2)Sb(1) 0(7) S(3) 138.8(2) Sb(1)ii 0(8) S(3) 140.7(2)Sb(1)Vi 0(9) S(3) 159.6(2)* Here and elsewhere superscripts refer to the symmetry operations:[SbF2( 03F)]:(a) 3/2-x, l/2+y, 1/2+z (b) 3/2-x, -l/2+y, 1/2+z (c) 1/2+x, l/2-y, z(d) 3/2-x, -l/2+y, -1/2+z (e) 3/2-x, 1/2+y, -112+z (f) -1/2+x, l/2-y, z(g) x, y, 1+z[SbF(SO3F)21x:(1)1-x, y-1/2, 1/2-z (2) -x, y-1/2, ‘/2+z (3) x, 14-y, z-!/2 (4) 1-x, V2+y, V2-z(5) x, l+y, z (6) x, y-l, z (7) -x, 1/2+y, 1/2-Z (8) x, ‘4-y, ‘/2+z[Sb(S03F)J:(1) y, -x+y, 1/6+z (ii) 1-x+y, 1-x, 1/3+z (iii) 1+x-y, x, -1/6+ziv) l-y, x-y, -1/3+z (v) x-y, x, -116+z (vi) y, 1-x+y, 1/6+z173Table D-7 Anisotropic Displacement Parametersatom U1 1 U22 U33 U12 U13U23[SbF2( 03F)]Sb(1) 0.01533(6) 0.01853(6) 0.02255(7) -0.00130(5) -0.0001(1) 0.0015(2)S(1) 0.0142(2) 0.0231(3) 0.0282(4) 0.0025(2) 0.0027(2) 0.0003(3)F(1) 0.130(3) 0.049(1) 0.036(2) 0.013(2) 0.010(3) 0.021(2)F(2) 0.038(1) 0.038(1) 0.033(1) 0.0074(9) -0.007(1) -0.012(1)F(3) 0.0237(9) 0.040(1) 0.044(1) -0.0009(8) -0.0025(9) 0.024(1)0(1) 0.0243(10) 0.027(1) 0.040(2) 0.0010(8) 0.001(1) -0.005(1)0(2) 0.0134(8) 0.030(1) 0.090(3) -0.0026(9) -0.002(1) 0.000(2)0(3) 0.0143(8) 0.043(1) 0.074(3) -0.0018(9) 0.007(1) -0.031(2)[SbF(SO3F)2jSb(1) 0.01854(4) 0.01910(5) 0.01915(4) -0.00112(5) 0.00796(3) -0.00061(4)S(1) 0.01433(14) 0.0215(2) 0.0166(2) -0.00072(14) 0.00576(12) -0.00115(14)S(2) 0.01564(15) 0.0259(2) 0.01612(15) 0.00249(15) 0.00743(12) 0.00062(14)F(1) 0.0246(5) 0.0214(6) 0.0333(6) -0.0019(5) 0.0111(5) 0.0019(5)F(2) 0.0276(6) 0.0523(9) 0.0191(5) -0.0074(6) 0.0058(4) -0.01 14(6)F(3) 0.0384(7) 0.0359(8) 0.0378(7) -0.0089(6) 0.0180(6) 0.0063(6)0(1) 0.0170(5) 0.0480(10) 0.0234(6) -0.0099(6) 0.0077(4) -0.0073(7)0(2) 0.0297(7) 0.0274(8) 0.0283(7) 0.0001(6) 0.0132(6) 0.0070(6)0(3) 0.0328(8) 0.0288(8) 0.0448(9) 0.0118(7) 0.0161(7) 0.0054 (7)0(4) 0.0224(6) 0.0437(9) 0.0220(6) 0.0070(6) 0.0117(5) -0.0045(6)0(5) 0.0238(6) 0.0313(8) 0.0224(6) 0.0054(6) 0.0063(5) 0.0061(6)0(6) 0.0222(6) 0.0470(10) 0.0187 (6) 0.0043 (7) 0.0067(5) -0.0075(6)[Sb(S03F)JSb(1) 0.0247(1) 0.0253(1) 0.01647(6) 0.01558(9) 0.00067(8) -0.00001(8)S(1) 0.0191(3) 0.0225(3) 0.0163(4) 0.0096(3) -0.0018(3) -0.0002(3)S(2) 0.0243(4) 0.0189(3) 0.0208(4) 0.0124(3) 0.0016(3) 0.0006(3)S(3) 0.0294(4) 0.0391(5) 0.0154(4) 0.0206(4) 0.0030(4) 0.0005(4)F(1) 0.030(1) 0.047(2) 0.048(2) -0.008(1) -0.002(2) -0.001(2)174atom U11 U22 U33 U12 U13 U23F(2) 0.030(1) 0.033(1) 0.060(2) 0.005(1) 0.014(1) 0.005(1)F(3) 0.028(1) 0.082(2) 0.044(2) 0.012(2) 0.015(1) 0.004(2)0(1) 0.027(1) 0.028(1) 0.0147(10) 0.014(1) -0.0010(9) 0.0021(9)0(2) 0.046(2) 0.054(2) 0.020(1) 0.040(2) 0.004(1) 0.007(1)0(3) 0.037(2) 0.033(1) 0.028(1) 0.025(1) 0.000(1) -0.007(1)0(4) 0.044(2) 0.026(1) 0.024(1) 0.024(1) -0.003(1) 0.000(1)0(5) 0.049(2) 0.041(2) 0.026(1) 0.033(2) -0.006(1) 0.000(1)0(6) 0.035(1) 0.029(1) 0.031(1) 0.020(1) 0.001(1) -0.007(1)0(7) 0.028(1) 0.030(1) 0.017(1) 0.012(1) 0.0043(9) -0.0033(10)0(8) 0.052(2) 0.046(2) 0.030(2) 0.029(2) -0.002(1) 0.013(1)0(9) 0.062(2) 0.054(2) 0.028(1) 0.046(2) -0.010(2) -0.012(2)The general temperature factor expression:For [SbF2( 03F)1:exp[_21t(a*2U11h2 + b*2U2k+ c*2U3312+ 2a*b*U12hk+ 2a*c*U13h1 + 2b*c*U3k11For [Sb(S03F)]:exp[2ic2(a* 2U11h2 b*2U2k+ c*2U3312+ 2a*b*U12hk+ 2a*c*U13h1+ 2b*c*U3k1]Table D-8. Torsion Ang1es()atom atom atom atom angle atom atom atom atom angle[SbF2( 03F)JSb(1) F(2) Sb(1)d F(2)d -168.5(1) Sb(1) F(2) Sb(1)d F(3)d -118.8(3)Sb(1) F(2) Sb(1)d 0(2)d -49.1(3) Sb(1) F(2)a Sb(1)a F(3)g 40.9(2)Sb(1) F(2)a Sb(1)a F(3)a -1 12.1(2) Sb(1) F(2)a Sb(1)a 0(2)a 170.8(3)Sb(1) F(3) Sb(1)e F(2)e 137.6(3) Sb(1) F(3) Sb(1)e F(3)e -163.8(2)Sb(1) F(3) Sb(1)e 0(2)e 67.0(4) Sb(1) F(3)b Sb(1) F(2)g -9.7(3)Sb(1) F(3)b Sb(1)b F(2)b 150.6(3) Sb(1) F(3)b Sb(1)b 0(2)b -124.5(3)Sb(1) 0(2) S(1) F(1) -102.8(6) Sb(1) 0(2) S(1) 0(1) 14.0(7)Sb(1) 0(2) S(1) 0(3) 149.0(5) S(1) 0(2) Sb(1) F(2) 24.7(6)175atom atom atom atom angle atom atom atom atom angleS(1) 0(2) Sb(1) F(2)a -178.1(5) S(1) 0(2) Sb(1) F(3) 114.2(6)S(1) 0(2) Sb(1) F(3)e -40.8(7) S(1) 0(2) Sb(1) 0(3)c 83.0(6)F(2) Sb(1) F(2)a Sb(1)a 168.5(1) F(3) Sb(1) F(3)b Sb(1)b 163.8(2)[SbF(S03F)2]Sb(1) 0(1) S(1) F(2) 149.5(2) Sb(1) 0(2)’ S(1)’ F(2)’ 97.3(1)Sb(1) 0(1) S(1) 0(2) 38.8(2) Sb(1) 0(2)’ S(1)’ 0(1)’ -156.0(1)Sb(1) 0(1) S(1) 0(3) -98.3(2) Sb(1) 0(2)’ S(1)’ 0(3)’ -20.2(2)Sb(1) 0(4) S(2) F(3) 97.0(2) Sb(1) 0(5)” S(2)” F(3)” 35.6(2)Sb(1) 0(4) S(2) 0(5) -14.6(2) Sb(1) 0(5)” S(2)” 0(4)” 145.7(1)Sb(1) 0(4) S(2) 0(6) -149.9(2) Sb(1) 0(5)” S(2)” 0(6)” -81.6(2)S(1) 0(1) Sb(1) F(1) 119.6(2) S(2) 0(4) Sb(1) F(1) -122.9(2)S(1) 0(1) Sb(1) 0(2)’ 39.3(2) S(2) 0(4) Sb(1) 0(1) 150.7(2)S(1) 0(1) Sb(1) 0(4) -153.0(2) S(2) 0(4) Sb(1) 0(2)’ 173.3(1)S(1) 0(1) Sb(1) 0(5)” 177.2(1) S(2) 0(4) Sb(1) 0(5)” -45.2(2)S(1) 0(2) Sb(1) F(1)* 47.3(1) S(2) 0(5) Sb(1) F(1)# -65.3(1)S(1) 0(2) Sb(1) 0(1)* 135.7(1) S(2) 0(5) Sb(1) 0(1)# -125.0(1)S(1) 0(2) Sb(1) 0(4)* 113.0(1) S(2) 0(5) Sb(1) 0(4)# -154.7(2)[Sb(S03F)]Sb(1) 0(1) S(1) F(1) 118.6(3) Sb(1) 0(1) S(1) 0(2) -130.0(3)Sb(1) 0(1) S(1) 0(3) 5.2(3) Sb(1) 0(2)a S(1)a F(1)a 84.5(4)Sb(1) 0(2)a S(1)a 0(1)a -24.7(5) Sb(1) 0(2)a S(1)a 0(3)a -158.6(3)Sb(1) 0(4) S(2) F(2) -104.1(4) Sb(1) 0(4) S(2) 0(5) 8.8(5)Sb(1) 0(4) S(2) 0(6) 145.7(4) Sb(1) 0(6)o S(2)c F(2)c -161.3(4)Sb(1) 0(6)c S(2)c 0(4)c -53.0(4) Sb(1) 0(6)c S(2)c 0(5)c 82.1(4)Sb(1) 0(7) S(3) F(3) 175.0(3) Sb(1) 0(7) S(3) 0(8) -73.9(3)Sb(1) 0(7) S(3) 0(9) 63.1(3) S(1) 0(1) Sb(1) 0(2)a -80.4(3)S(1) 0(1) Sb(1) 0(3)b 151.9(2) S(1) 0(1) Sb(1) 0(4) 122.5(3)S(1) 0(1) Sb(1) 0(5)a -88.1(3) S(1) 0(1) Sb(1) 0(6)c 49.5(3)176atom atom atom atom angle atom atom atom atom angleS(1) 0(1) Sb(1) 0(7) -154.0(3) S(1) 0(2) Sb(1)e 0(1)e -116.3(4)S(1) 0(2) Sb(1)e 0(4)e -74.0(5) S(1) 0(2) Sb(1)e 0(5) 57.9(4)S(1) 0(2) Sb(1)e 0(6)g -176.3(4) S(1) 0(2) Sb(1)e 0(7)e -28.6(4)S(1) 0(3) Sb(1)d 0(1)d -109.4(4) S(1) 0(3) Sb(1)d 0(4)d -77.8(4)S(1) 0(3) Sb(1)d 0(7)d -164.8(4) S(2) 0(4) Sb(1) 0(1) -27.3(4)S(2) 0(4) Sb(1) 0(2)a -67.5(5) S(2) 0(4) Sb(1) 0(3)b 170.1(4)S(2) 0(4) Sb(1) 0(5)a -178.9(3) S(2) 0(4) Sb(1) 0(6)c 50.4(4)S(2) 0(4) Sb(1) 0(7) -1 10.6(4) S(2) 0(5) Sb(1)e 0(1)e -124.6(4)S(2) 0(5) Sb(1)e 0(2) -132.6(4) S(2) 0(5) Sb(1)e 0(4)e 11.7(5)S(2) 0(5) Sb(1)e 0(6)g 116.8(4) S(2) 0(5) Sb(1)e 0(7)e -57.7(4)S(2) 0(6) Sb(1)f 0(1)f -122.0(4) S(2) 0(6) Sb(1)f 0(2)h -64.3(4)S(2) 0(6) Sb(1)f 0(4)f 151.8(4) S(2) 0(6) Sb(1)f 0(5)h 19.7(5)S(2) 0(6) Sb(1)f 0(7)f -170.5(3) S(3) 0(7) Sb(1) 0(1) -137.3(3)S(3) 0(7) Sb(1) 0(2)a 149.9(3) S(3) 0(7) Sb(1) 0(3)b 14.7(3)S(3) 0(7) Sb(1) 0(4) -54.3(3) S(3) 0(7) Sb(1) 0(5)a 82.1(3)S(3) 0(7) Sb(1) 0(6)c -90.2(3)Table D-9 Non-bonded Contactsatom atom distance ADC atom atom distance ADC[SbF2( 03F)]Sb(1) 0(1) 2.946(3) 65502 S(1) F(3) 3.177(2) 45504S(1) 0(1) 3.365(3) 65502 S(1) F(2) 3.489(3) 65502F(1) 0(2) 2.978(4) 66402 F(1) 0(3) 3.107(7) 55401F(1) 0(1) 3.191(5) 65402 F(1) 0(2) 3.371(8) 55401F(1) F(2) 3.390(6) 65402 F(1) F(3) 3.448(5) 66402F(1) F(3) 3.477(5) 45504 F(2) F(3) 2.952(4) 64403F(2) 0(1) 3.005(4) 65402 F(2) 0(3) 3.124(5) 65402F(2) 0(1) 3.208(4) 65502 F(3) 0(3) 2.786(4) 664020(1) 0(2) 2.940(5) 65402 0(1) 0(1) 3.095(3) 65502177atom atom distance ADC atom atom distance ADC0(1) 0(1) 3.095(3) 65402 Sb(1) Sb(1) 4.5073(4) 65503Sb(1) Sb(1) 5.0239(9) 55601 Sb(1) Sb(1) 6.7217(3) 4[SbF(S03F)2]Sb(1) 0(6) 2.995(2) 55404 Sb(1) F(1) 3.098(2) 56501Sb(1) 0(3) 3.055(2) 65502 Sb(1) 0(3) 3.477(2) 2S(1) 0(6) 3.316(2) 66603 S(1) F(1) 3.419(1) 65502S(1) F(2) 3.517(2) 66603 S(2) 0(6) 3.252(2) 56603S(2) F(2) 3.374(1) 66603 S(2) 0(3) 3.542(2) 65603S(2) F(1) 3.583(1) 56501 S(2) F(1) 3.598(1) 2F(1) F(2) 2.918(2) 65603 F(1) 0(4) 3.181(2) 54501F(1) 0(5) 3.249(2) 54501 F(1) 0(1) 3.489(2) 54501F(2) F(2) 2.805(3) 66603 F(2) 0(6) 2.920(2) 66603F(2) 0(4) 3.051(2) 66603 F(2) 0(1) 3.094(2) 66603F(2) 0(1) 3.223(3) 65603 F(2) 0(4) 3.515(2) 65603F(3) F(3) 2.722(3) 55603 F(3) 0(5) 3.035(3) 54501F(3) 0(6) 3.198(2) 56603 F(3) 0(6) 3.378(2) 55603F(3) 0(6) 3.588(3) 54501 0(2) 0(3) 2.883(3) 565010(2) 0(6) 3.099(2) 66603 0(2) 0(3) 3.181(2) 655020(2) 0(2) 3 .255(2) 65502 0(3) 0(6) 3.065(2) 656030(3) 0(4) 3.184(2) 65603 0(3) 0(6) 3.396(3) 666030(5) 0(6) 3.153(2) 56603 0(5) 0(5) 3.184(2) 20(6) 0(6) 2.946(3)[Sb(S03F)]Sb(1) 0(8) 3.009(4) 65402 S(1) 0(7) 3.349(3) 55406S(1) 0(9) 3.483(4) 66404 S(2) 0(8) 3.420(4) 55406S(2) 0(3) 3.472(3) 56505 S(3) 0(2) 3.446(4) 66504S(3) 0(8) 3.489(3) 55406 F(1) F(2) 3.286(4) 54406F(1) 0(7) 3.419(5) 55406 F(1) 0(4) 3.465(5) 65402178atom atom distance ADC atom atom distance ADCF(1) F(1) 3.518(2) 55406 F(2) F(3) 3.019(5) 66402F(2) F(3) 3.169(4) 66406 F(2) F(2) 3.405(2) 56505F(3) 0(8) 3.343(6) 55406 .F(3) 0(5) 3.379(5) 56503F(3) F(3) 3.530(2) 55406 0(1) 0(7) 3.250(4) 554060(2) 0(7) 2.737(4) 55406 0(2) 0(9) 2.920(5) 664040(2) 0(8) 3.050(5) 66404 0(2) 0(3) 3.554(4) 554060(3) 0(4) 2.695(4) 65402 0(3) 0(8) 2.959(5) 654020(3) 0(7) 2.971(4) 65402 0(3) 0(9) 3.062(5) 664040(3) 0(9) 3.270(5) 65402 0(5) 0(9) 3.044(5) 664020(5) 0(7) 3.188(5) 55406 0(5) 0(8) 3.426(6) 554060(6) 0(8) 3.119(5) 55406 0(7) 0(8) 3.461(4) 55406specifies the position of an atom in a crystal. The 5-digitThe ADC (atom designator code)number shown in the table is anumber: TA (first digit) + TB (second digit) + TC (third digit) + SN (last two digits). TA, TBand TC are the crystal lattice translation digits along cell edges a, b and c. A translation digit of5 indicates the origin unit cell. If TA = 4, this indicates a translation of one unit cell lengthalong the a-axis in the negative direction. Each translation digit can range in value from 1 to 9and thus ±4 lattice translations from the origin (TA5, TB5, TC=5) can be represented.The SN, or symmetry operator number, refers to the number of the symmetry operator used togenerate the coordinates of the target atom. A list of symmetry operators relevant to thisstructure are given below.For a given intermolecular contact, the first atom (origin atom) is located in the origin unit celland its position can be generated using the identity operator (SN1). Thus, the ADC for anorigin atom is always 55501. The position of the second atom (target atom) can be generatedusing the ADC and the coordinates of the atom in the parameter table. For example, an ADC of47502 refers to the target atom moved through symmetry operator two, then translated -1 cellcomposite of three one-digit numbers and one two-digit179translations along the a axis, +2 cell translations along the b axis, and 0 cell translations alongthe c axis. An ADC of 1 indicates an intermolecular contact between two fragments (eg. cationand anion) that reside in the same asymmetric unit.Symmetry Operators:[SbF2( O3F)lx (1) x, y, z (2) -x, -y, 1/2+z(3) 112-x, l/2+y, 1/2+z (4) 1/2+x, l/2-y, z[SbF (SO3F)2}x (1) x, y, z (2) -x, V2+y, 1/2-z (3) -x, -y, -z (4) x, ‘4-y, Yz+z[SbF(SO3F)1x (1) x, y, z (2) -x, x-y, 2/3+z (3) -x+y, -x, 113+z(4) -x, -y, V2-I-z (5) y, -x+y, 1/6+z (6) x-y, x, 5/6+z180AppendixEListof CrystallographicDataandSelectedStructureParametersforCsSO3F,Cs[H(SO3F)21,Cs[Au(SO3F)41,Cs2[Pt(SO3F)6j,andCs[Sb(SO3F)61TableE-1CrystalData.CompoundCsSO3FCs[H(SO3F)2]Cs[Au(SO3F)41Cs2[Pt(SO3F)6]Cs[Sb(SO3F)61FormulaWeight231.96332.03726.101055.24848.99CrystalColor, Habitcolorless,prismcolorless,prismyellow,needleyellow,prismColorless,cubicCrystal Dimensions(mm)0.15x0.20x0.350.30x0.30x0.450.10x0.15x0.450.20x0.30x0.300.35x0.35x0.35Crystal SystemmonoclinicmonoclinicmonoclinictrigonalTrigonalLatticeTypePrimitiveC-centeredC-centeredPrimitiveR-centeredNo.of ReflectionsUsedfor2525252525Unit CellDetermination(20)(52.9-58.6°)(42.9-48.1°)(31.1-41.5°)(31.8-40.2°)(42.1-44.6°)OmegaScanPeakWidth0.35°0.38°0.33°0.36°0.37°atHalf-heightLatticeParametersa=7.7243(6)Aa13.371(2)Aa17.725(2)Aa=9.070(1)Aa=12.0317(7)Ab=8.1454(6)Ab=7.731(2)Ab=5.822(2)Ac=7.7839(7)Ac=9.485(2)Ac14.624(2)Ac=7.6028(7)Ac=12.026(2)Af=110.832(7)°=128.375(7)°=102.120(9)°V=457.72(7)A3V=768.6(3)A3V=1475.5(5)A3V=541.64(6)A3V=1507.6(2)A3SpaceGroupP21/a(#14)C2/c(#15)C2/c(#15)P321(#150)R3(#148)Zvalue44413Dcalc(g/cm3)3.3662.8693.2683.2352.805F00041661613204821200j.t(MoKoc)(cm-i)84.4453.83131.03104.6939.1500TableE-2.IntensityMeasurements.CompoundCsSO3FCs[H(SO3F)2]Cs[Au(SO3F)4]ICs2[Pt(SO3F)6JICs[Sb(SO3F)61DiffractometerRigakuAFC6SRadiationMoKcx(2k.=0.71069A),graphitemonochromatedTake-offAngle6.0°Detector Aperture6.0mmhorizontal,6.0mmverticalCrystal toDetector Distance285mmTemperature21°CScanTypeScanRate32°/mm(in2)(upto9scans)ScanWidth(1.21+0.35tan)°(1.26+0.35tanO)°(1.21+0.35tanO)°(1.31+0.35tanO)°(1.42+0.35tanO)°2Om100°75°70°75°100°No.of ReflectionsTotal:5221Total:2200;Total:3599,Total:2154,Total:3763;MeasuredUnique:5006Unique:2130Unique:3506Unique:1912Unique:3502(Rmt=0.027)(R1=0.019)(Rint=0.026)(Rint=0.133)(Pint=0.042)CorrectionsLorentz-polarizationAbsorption(trans.factors)0.723-1.0000.92-1.000.373-1.0000.616-1.000)0.739-1.000SecondaryExtinction1.39(2)x1064.06(6)x106(coefficientDecay11.5%decline00TableE-3StructureSolutionandRefinement.CompoundCsSO3FCs[H(SO3F)2]Cs[Au(SO3F)4]Cs2[Pt(SO3F)6]Cs[Sb(SO3F)6]PattersonMethodsPattersonMethodsDirectMethodsDirectMethodsPattersonMethodsStructureSolution(DIRDIF92I(DIRDIF92(S1R92)(S1R92)(DIRDIF92PATTY)jPATFY)PATTY)RefinementFull-matrixleast-squaresFunctionMinimizedw(Fo-IFcI)2LeastSquaresWeightsl/(Fo)=4Fo21a(Fo)p-factor0.000AnomalousDispersionAllnon-hydrogenatomsNo.Observations(I>3G(I))2321136216717381485No.Variables56531225151ReflectionlParameterRatio41.4525.713.70.14.4729.12Residuals:R;Rw0.029;0.0270.027;0.0260.030;0.0290.048;0.0450.039;0.037Goodnessof FitIndicator1.731.771.632.312.16MaxShift/Error inFinal0.00090.00050.00020.0030.0003CycleMaximumpeakinFinal0.90e7A30.46e/A30.93e/A32.63e/A31.51e/A3Diff. MapMinimumpeakinFinal-0.92e/A3-0.51e/A3-1.58eiA3-1.96e/A3-2.17e/A3Diff. Map00Table E-4. Atomic coordinates and equivalent isotropic thermal parameters.2Atom x y z Be/BCsSO3FCs( 1) 0.29378(2) 0.62899(2) 0.28431(2) 2.152(3)S(1) 0.27984(8) 0.12745(8) 0.25185(9) 1.746(10)F(1) 0.1314(3) 0.2213(3) 0.0897(3) 4.61(6)0(1) 0.4085(3) 0.0694(3) 0.1663(3) 2.73(5)0(2) 0.3591(3) 0.2465(3) 0.3945(3) 3.01(5)0(3) 0.1875(4) -0.0043(3) 0.3070(4) 3.23(5)Cs[H(SO3F)2]Cs(1) 1/2 0.61572(3) 1/4 3.090(5)S(1) 0.33046(6) 0.15138(9) 0.28020(9) 2.79(1)F(1) 0.3997(3) -0.0144(3) 0.2969(3) 6.55(6)0(1) 0.4229(2) 0.2824(3) 0.3495(3) 4.88(5)0(2) 0.2837(3) 0.1186(4) 0.3749(4) 5.82(8)0(3) 0.2290(2) 0.1621(3) 0.0847(3) 4.33(5)H(1) 1/4 1/4 0 7(1)Cs[Au(SO3F)4]Au(1) 1/4 1/4 1/2 2.723(6)Cs(1) 1/2 0.3605(1) 3/4 4.49(1)S(1) 0.3147(1) -0.1234(3) 0.6460(1) 4.18(4)S(2)b 0.4006(6) 0.205(1) 0.4432(7) 4.7(2)S(2a)c 0.412(1) 0.261(8) 0.435(2) 7.2(5)F(1) 0.2412(3) -0.161(1) 0.6823(4) 7.9(2)F(2)b 0.4083(4) -0.062(2) 0.4374(6) 8.9(3)F(2a)c 0.406(1) 0.543(5) 0.439(2) 9.1(8)0(1) 0.2828(3) -0.0600(7) 0.5453(3) 4.1(1)0(2) 0.3517(3) 0.0604(9) 0.6978(3) 5.7(1)0(3) 0.3474(4) -0.343(1) 0.6469(4) 7.0(2)0(4) 0.3183(3) 0.2250(8) 0.4096(3) 4.3(1)0(5) 0.4316(3) 0.247(1) 0.5343(4) 8.3(2)184Atom x y z B/B0(6) 0.4409(4) 0.256(1) 0.3725(4) 9.0(2)Cs2[Pt(SO3F)6]Pt(1) 0 0 0 1.609(8)Cs(1) 1/3 -1/3 0.3331(1) 3.55(1)S(1) 0.3432(5) 0.164(2) 0.2204(5) 5.5(1)F(1) 0.459(1) 0.218(4) 0.055(1) 10.6(4)0(1) 0.194(1) 0.160(1) 0.1495(10) 3.2(2)0(2) 0.313(2) -0.009(2) 0.256(2) 7.1(4)0(3) 0.432(1) 0.292(1) 0.338(1) 5.1(3)Cs[Sb(SO3F)6]Cs(1) 0 0 0 3.688(7)Sb(1) 0 0 1/2 1.869(4)S(1) 0.23450(10) 0.17073(10) 0.33273(9) 4.64(2)F(1) 0.2413(3) 0.2824(2) 0.3919(3) 6.87(7)0(1) 0.1546(2) 0.0589(2) 0.4097(2) 3.00(4)0(2) 0.3558(3) 0.1830(3) 0.3234(3) 6.04(7)0(3) 0.1648(4) 0.1553(4) 0.2342(3) 7.9(1)a Beg = (8/3)p2SSUL,a*Ia*J(af.aJ), b population = 0.73(1), C population = 0.27Table E-5. Bond lengths (A) with estimated standard deviations in length bond lengthCsSO3FCs(1)_F(1)a 3.252(2) Cs(1)_0(1)a 3.329(2)Cs(1)—0(1 )b 3.220(2) Cs(1 )—0(2) 3.223(3)Cs(1)0(2)C 3.265(2) CS(1)0(2)d 3.115(2)Cs(1)_0(3)e 3.151(2) Cs(1)___0(3)c 3.316(3)Cs(1)—0(3) 3.119(2) S(1)—F(1) 1.569(2)S(1)—O(1) 1.458(2) S(1)—0(2) 1.437(2)S(1)—0(3) 1.436(2)185bond length bond lengthCs[H(SO3F)21Cs(1)_F(1)a 3.303(2) Cs(1)—O(1) 3.131(2)Cs( 1 )—O( 1 )b 3.354(3) Cs( 1 )_O(2)c 3.196(3)Cs( 1 )O(2)b 3.530(3) Cs( 1 )(3)d 3.464(2)S(1)—F(1) 1.531(2) S(1)—O(1) 1.406(2)S(1)—O(2) 1.399(3) S(1)—O(3) 1.471(2)O(3)—H(1) 1.210(2)Cs[Au(SO3F)4]Au(1)—O(1) 1.968(4) Au(1)—O(4) 1.976(4)Cs( 1 )_F(2a)a 3.56(3) Cs( 1)—O(2) 3.115(5)Cs( 1 )_O(3)b 3.295(6) Cs( 1 )—O(5) 3.202(5)Cs(1)_O(6)a 3.177(7) S(1)—F(1) 1.523(6)S(1)—O(1) 1.508(4) S(1)—O(2) 1.393(5)S(1)—O(3) 1.402(6) S(2)—F(2) 1.56(1)S(2)—O(4) 1.44(1) S(2)—O(5) 1.35(1)S(2)—O(6) 1.41(1) S(2a)—F(2a) 1.65(4)S(2a)—O(4) 1.64(2) S(2a)—O(5) 1.42(3)S(2a)—O(6) 1.14(3)Cs2[Pt(SO3F)6]Pt(1)—O(1) 1.987(8) Cs(1)_F(1)a 3.371(9)Cs(1)—O(2) 3.10(1) Cs(1)_O(3)b 3.184(9)S(1)—F(1) 1.555(9) S(1)—O(1) 1.44(1)S(1)—O(2) 1.48(2) S(1)—O(3) 1.36(1)Cs{Sb(SO3F)6jCs( 1 )__O(2)a 3.241(3) Cs( 1 )—O(3) 3.413(4)Sb(1)—O(1) 1.955(2) S(1)—F(1) 1.486(3)S(1)—O(1) 1.516(2) S(1)—O(2) 1.396(3)S(1)—O(3) 1.409(4)186Superscripts refer to symmetry operations:for CsSO3F; (a) 1/2-x, l/2+y, -z (b) -1/2+x, l/2-y, z (c) 1/2-x, l/2+y, 1-z (d) 1-x, l-y, 1-z(e) 1/2+x, 1/2-y,z(f)x, 1+y,z;for Cs[H(SO3F)2]; (a) x, l+y, z (b) 1-x, l-y, 1-z (c) 1/2+x, l/2+y, z (d) 112-x, l/2-y, -z;for Cs[Au(SOF)41:(a) x, l-y, 1/2+z (b) x, l+y, z;forCs2[Pt(SO3F)6];(a) x-y, -y, -z (b) y, -1+x, 1-z;for Cs[Sb(SOF)]:(a) 2/3-x, l/3-y, 1/3-z.Table E-6. Bond Angles(°) with estimated standard deviations in parentheses.atoms angle atoms angleCsSO3FF( 1 )aCS( 1 )—0( 1 ) 41.97(5) F( 1 )aCS( 1 )—0( 1 )b 107.53(6)F(1 )a_CS( 1 )—0(2) 113.64(6) F( 1)a_Cs( 1 )__0(2)c 147.75(6)F(1 )aCS( 1 )_0(2)d 105.48(6) F( 1 )aCS( 1 )_0(3)e 69.47(7)F(1)a___Cs( 1)_0(3)c 166.87(6) F( 1 )a_CS( 1)—0(3) 87.91(7)0( 1)a___Cs( 1 )—O( 1)” 65.57(6) 0(1 )a_Cs( 1 )—0(2) 96.32(6)O(1)a__..Cs( 1 )_0(2)c 133.43(6) 0( 1)a_Cs( 1 )_0(2)d 147.21(6)0(1)a_Cs( 1)_0(3)e 95.40(6) 0(1 )aCs(1)_0(3)c 143.82(6)0(1 )a_CS( 1 )—0(3) 99.49(7) 0(1)’Cs( 1 )—0(2) 68.41(6)0(1)t’_Cs( 1 )_0(2)c 79.42(6) 0(1 )b_Cs( 1 )—0(2)” 146.83(6)0(1)’—Cs( 1 )___0(3)c 129.04(6) 0(1 )b_CS( 1)_0(3)c 80.20(6)0(1)b_C5( 1)—0(3) 105.17(6) 0(2)—Cs( 1 )_0(2)c 98.31(5)0(2)_Cs(1)_O(2)d 95.31(6) O(2)Cs(1)__O(3)e 67.49(6)0(2)—Cs( 1 )_0(3)c 58.58(6) 0(2)—Cs( 1 )—0(3) 158.42(6)0(2)c___Cs( 1 )_0(2)’ 74.49(5) 0(2)c__Cs( 1 )_0(3)e 131.01(7)0(2)’_Cs( 1 )_0(3)c 42.74(6) 0(2)c_Cs( 1 )—0(3) 60.12(6)0(2)dCs( 1 )_0(3)e 61.42(7) 0(2)d_Cs( 1 )_0(3)c 66.75(6)0(2)d_CS( 1 )—0(3) 79.14(7) 0(3)e_Cs( 1 )_0(3)c 97.40(6)0(3)c_Cs( 1)—0(3)” 125.00(7) 0(3)c_Cs(1 )—0(3) 100.48(5)F(1)—S(1)—0(1) 102.3(1) F(1)—S(1)—0(2) 106.3(1)F(1)—S(1)—0(3) 107.8(2) 0(1)—S(1)—0(2) 113.6(1)0(1)—S(1)—0(3) 112.7(1) 0(2)—S(1)—0(3) 113.2(1)187atoms angle atoms angleCs(1)8—F(1)—S(1) 107.2(1) cs(1)e___o(1)__cs(1y 114.43(6)Cs(1)e___O(1)_S(1) 138.0(1) Cs(1)__O(1)_g(1) 107.1(1)Cs( 1 )—O(2)——-Cs( 1 )h 114.98(7) Cs( 1 )—0(2)——Cs( 1 )d 84.69(6)Cs(1)—0(2)——S(1) 117.6(1) Cs(l)h_0(2)__.Cs(l)dI 85.61(6)Cs(1)h___0(2)—S(1) 102.9(1) Cs(1)d_O(2)___S(1) 148.0(1)Cs( 1)b___O(3) —Cs( 1) 87.50(6) Cs( 1)b__O(3)_Cs( 1)h 82.60(6)Cs(1)b___O(3)—S(1) 142.7(1) Cs(1)’—O(3) ___CS(1)b 116.45(8)Cs(1)’—0(3) —S(1) 122.0(1) CS(1)h_O(3)—S(1) 100.7(1)Cs[H(SO3F)2]F(ly_cs(1)_F(ly 60.1(1) F(1)a___Cs(1)_O(1) 115.76(8)94.83(6) 171.97(6)60.61(6) F(1)a___cs(1)___o(2y 115.57(8)F(1)3—Cs( 1)___0(2)h 63.66(7) F( 1)a___Cs( 1)—0(2) 59.01(6)60.51(6) F(1)3Cs(1)—0(3’ 117.27(6)F(1)a___Cs( 1)—O(3)’ 127.96(6) 0(1 )—Cs( I )—0( 1) 127.40(6)0(1 )—Cs( 1 )—0( 1 ) 69.2(1) 0(1 )—Cs( 1 )—0( 1 )“ 77.24(7)0( 1)—Cs( 1 )_0(2)c 115.55(7) 0(1 )—Cs( 1 )_0(2)” 65.18(8)0(1 )—Cs(1 )—0(2) 124.44(6) 0(1 )—Cs( 1 )_0(2)” 113.08(6)0(1)__CS(1)_0(3)d 59.78(5) 0(1)—Cs(1)——-0(3)’ 58.86(7)0( 1)—Cs( 1 )—0( 1 )b 152.84(8) 0(1)1—Cs( 1 )—0(2) 82.98(7)0( 1)—Cs( 1)0(2)h 96.83(7) 0( 1)’—Cs( 1)—0(2) 40.41(6)0( 1)—Cs(1 )_0(2)b 119.23(6) 0(1 )L—Cs( 1)__0(3)d 68.43(6)0( 1)—Cs( 1)—0(3)’ 131.20(6) 0(2)Cs(1)_0(2)h 179.2(1)0(2)c_Cs(1)_0(2)I 114.25(6) 0(2)c_Cs(1)_0(2)b 65.24(8)0(2)c___Cs( 1 )_0(3)d 120.99(8) 0(2)c_Cs( 1 )—0(3)’ 59.59(6)0(2)t—Cs( 1 )_0(2)” 108.85(9) 0(2)1—Cs( 1 )—0(3) 74.46(7)0(2)—Cs( 1 )—0(3)’ 171.61(6) 0(3)d_Cs( 1 )—0(3)’ 103.37(8)F(1)—S(1)-——0(1) 104.8(2) F(1)—S(1)—0(2) 105.3(2)F(1)—S(1)-—0(3) 101.7(1) 0(1)—S(1)-—0(2) 116.3(2)188atoms angle atoms angleO(1)—S(1)———O(3) 113.8(1) O(2)—S(1)-—--O(3) 113.0(2)Cs(1)—F(1)—S(1) 168.8(1) Cs(1)—O(1)——-Cs(1)” 102.76(7)Cs(1)—O(1)—S(1) 144.1(1) CS(1)’O(l)S(1) 105.2(1)Cs(1)k_O(2)_Cs(1)b 114.76(8) CS(1)k_O(2)_S(1) 131.6(2)Cs(1)b__O(2)_S(1) 97.4(1) Cs(1)’—O(3)—S(1) 136.0(1)Cs(1)d___O(3)__H(1) 100.2(1) S(1)—O(3)——H(1) 117.1(2)O(3)_H(1)O(3)d 180.0Cs[Au(SO3F)4JO(1)_Au(1)_O(1)c 180.0 O(1)—Au(1)—O(4) 88.8(2)O( 1)—Au( 1 )O(4)c 91.2(2) O(4)—Au( 1 )_O(4)c 180.0F(2a)a__Cs( 1 )_F(2a)d 161.9(9) F(2a)a.__Cs( 1 )—O(2) 76.6(4)F(2a)a__Cs( 1 )O(2)c 114.1(4) F(2a)Cs( 1 )___O(3)b 78.4(4)F(2a)a_Cs( I )—O(3) 92.1(4) F(2a)a__Cs( 1)—O(5) 130.9(4)F(2a)a_Cs( 1)O(5y 53.9(4) F(2a)’_Cs( 1 )_O(6)a 357(5)F(2a)—Cs( 1)_O(6)d 126.2(5) O(2)—Cs( 1)_O(2)e 111.8(2)O(2)—Cs( 1)_O(3)” 67.2(2) O(2)—Cs( 1 )—O(3)’ 167.3(1)O(2)—Cs(1)—--O(5) 61.1(1) O(2)__Cs(1)___O(5)e 104.5(1)O(2)—Cs( 1 )_O(6)a 99.9(2) O(2)—Cs( I )O(6)” 128.2(1)O(3)t’—Cs(1)-—-O(3) 116.8(2) O(3)b___Cs(1)_O(5) 63.4(2)O(3)”_Cs( 1 )_O(5)e 131.6(2) O(3)’_Cs( 1 )_O(6)a 63.5(2)O(3)b_CS( 1 )_O(6)d 73.1(2) O(5)—Cs( 1 )_O(5)e 156.1(3)O(5)—Cs( 1 )_O(6)a 126.8(2) O(5)—Cs( 1)O(6)” 72.0(2)90.6(3) F(1)—S(1)—-—O(1) 101.7(3)F(1)—S(1)———O(2) 105.1(4) F(1)—S(1)-——O(3) 104.3(4)O(1)—S(1)--—O(2) 112.4(3) O(1)—S(1)—-—O(3) 107.5(3)O(2)—S( 1 )—O(3) 123.3(3) F(2)—S(2)—O(4) 99.0(6)F(2)—S(2)—O(5) 102.2(7) F(2)—S(2)—O(6) 96.1(6)O(4)—S(2)—O(5) 119.5(7) O(4)—S(2)——O(6) 111.4(8)O(5)—S(2)-—O(6) 121.5(8) F(2a)—S(2a)—O(4) 93(2)189atoms angle atoms angleF(2a)—S(2a)—O(5) 91(2) F(2a)—S(2a)—O(6) 95(2)O(4)—S(2a)—O(5) 103(1) O(4)—S(2a)—O(6) 114(2)O(5)—S(2a)—O(6) 140(2) Cs( 1 )—F(2a)—S(2) 102.2(10)Cs(1)—F(2a)—S(2a) 94(1) Au(1)—O(1)—S(1) 125.2(3)Cs( 1)—O(2)—S( 1) 147.2(4) Cs( 1) 141.2(3)Au(1)—O(4)—S(2) 119.8(4) Au(1)—O(4)—S(2a) 124(1)Cs(1)—O(5)—S(2) 177.9(6) Cs( 1)—O(5)—S(2a) 162(1)Cs( l)d__O(6)_S(2) 147.3(5) Cs( 1)d_O(6)_S(2a) 133(2)Cs2[Pt(SO3F)6]O(1)_Pt(1)_O(1)c 90.5(4) O(1)_Pt(1)_O(1)e 72.0(5)O(1)—Pt(1)——-O(1) 146.5(5) o(1)pt(l)—o(1y 117.3(5)F( 1)a__Cs( 1 )—F( 1 ) 49.7(3) F( 1 )a_CS( 1 )—O(2) 52.9(5)F(1)a___Cs( 1 )___O(2)h 83.8(6) F( 1)a(I )—O(2)’ 102.5(5)F(1y—cs(1)o(3’ 158.5(6) F(1)a___Cs(1)_O(3)J 114.4(3)F( 1)a_CS( 1 )_O(3)c 135.7(5) O(2)—Cs( 1 )_O(2)h 116.5(2)O(2)—Cs( 1)_O(3)b 137.9(4) O(2)—Cs( l)—O(3) 74.8(4)O(2)—Cs( 1)_O(3)k 88.0(3) O(3)°—Cs( 1 )—O(3)’ 64.9(3)F(1)—S(1)—O(1) 100.6(9) F(1)—S(1)—O(2) 102(1)F(1)—S(1)—O(3) 104.5(10) O(1)—S(1).—---O(2) 111.6(8)O(1)—S(1)—O(3) 114(1) O(2)—S(1)—O(3) 120(1)Cs(1)’—F(l)—S(l) 172(1) Pt(1)—O(1)———S(1) 135.3(7)Cs(1)—O(2)—S(1) 167.7(8) Cs(1)m—O(3)—S(1) 133.6(9)Cs[Sb(SO3F)6]O(2)a__Cs( 1 )_O(2)b 180.0 o(2y—cs( 1 )_O(2)c 1 19.865(7)o(2y.—cs( 1 )—O(2)’ 60.135(8) O(2)2—Cs( 1 )—O(3) 58.1 1(9)O(2)a_Cs( 1 )_O(3)e 1 16.68(7) O(2)a_CS( I )—O(3) 89.31(10)O(2y_Cs( 1 )—O(3) 121.89(9) O(2)a__Cs( 1 )_O(3)h 63.32(7)O(2)a__Cs( 1 )—O(3) 90.69(10) O(3)—Cs( 1 )_O(3)e 58.59(9)O(3)—Cs( 1 )_O(3) 180.0 O(3)—Cs( 1 )__O(3)h 121.41(9)190bond length bond lengthO(1)_Sb(1)___O(1)e 92.15(9) O(1)—Sb(1)———O(1) 180.0O(1)_Sb(1)_O(1)k 87.85(9) F(1)—S(1)—O(1) 103.5(1)F(1)—S(1)—O(2) 111.1(2) F(1)—S(1)—O(3) 106.4(2)O(1)—S(1)—O(2) 108.0(2) O(1)—S(1)-----O(3) 109.0(2)O(2)—S(1)——O(3) 117.9(2) Sb(1)—O(1)-—-S(1) 136.6(1)Cs(1)’—O(2)—S(1) 155.5(2) Cs(1)—O(3)—S(1) 155.6(2)Superscripts refer to the symmetry operations:for CsSO3F: (a) 1/2-x, l!2+y, -z (b) -1/2+x, l/2-y, z (c) 1/2-x, l/2+y, 1-z(d) 1-x, l-y, 1-z(e) 1/2+x, 1/2-y,z(f)x, 1+y,z(g) 1/2-x, -l/2+y, -z (h) 1/2-x, -l/2+y, 1-z (i) x, -l+y, z;for Cs[H(SO3F)2j: (a) x, l+y, z (b) 1-x, l-y, 1-z (c) 1/2+x, l/2+y, z (d) 1/2-x, l/2-y, -z(e) 1-x, l+y, 1/2-z (f) x, l-y, -1/2+z (g) 1-x, y, 1!2-z (h) 1/2-x, l/2+y, 1/2-z(i) 1/2+x, 1/2-y, 1/2+z U) x, -l+y, z (k) -1/2+x, -l/2+y, z;for Cs[Au(SO3F)4]: (a) x, l-y, 1/2+z (b) x, l+y, z (c) 1/2-x, l/2-y 1-z (d) 1-x, l-y, 1-z(e) 1-x,y, 3/2-z (f) 1-x, l+y, 3/2-z (g) x, -l+y, z;forCs2[Pt(SO3F)6]: (a) x-y,-y, -z (b) y, -1+x, 1-z (c) -y, x-y, z (d) -x+y, -x, z (e) y, x, -z(f) -x, -x+y, -z (g) y, -1+x, -z (h)-y, -1+x-y, z (i) 1-x+y, -x, z(j) x-y, -z, 1-z (k) 1-x, -x+y, 1-z (1) l+y, x, z (m) l+y, x, 1+z;for Cs[Sb(SO3F)61: (a) 2/3-x, l/3-y, 1/3-z (b) -2/3+x, -1/3+y-1/3+z(c) -1!3+x-y, -2/3+x, 1/3-z (d) l/3-y, -1/3+x-y, -1/3+z (e) -y, x-y, z(f) -x+y, -x, z (g) -x, -y, -z (h) y, -x+y, -z (i) x-y, x, -z (J) -x, -y 1-z(k) y, -x+y, 1-z (1) 2/3+x, l/3+y, 1/3+z.191


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