{"http:\/\/dx.doi.org\/10.14288\/1.0060611":{"http:\/\/vivoweb.org\/ontology\/core#departmentOrSchool":[{"value":"Science, Faculty of","type":"literal","lang":"en"},{"value":"Chemistry, Department of","type":"literal","lang":"en"}],"http:\/\/www.europeana.eu\/schemas\/edm\/dataProvider":[{"value":"DSpace","type":"literal","lang":"en"}],"https:\/\/open.library.ubc.ca\/terms#degreeCampus":[{"value":"UBCV","type":"literal","lang":"en"}],"http:\/\/purl.org\/dc\/terms\/creator":[{"value":"Dekleva, Thomas William","type":"literal","lang":"en"}],"http:\/\/purl.org\/dc\/terms\/issued":[{"value":"2010-05-02T22:14:54Z","type":"literal","lang":"en"},{"value":"1983","type":"literal","lang":"en"}],"http:\/\/vivoweb.org\/ontology\/core#relatedDegree":[{"value":"Doctor of Philosophy - PhD","type":"literal","lang":"en"}],"https:\/\/open.library.ubc.ca\/terms#degreeGrantor":[{"value":"University of British Columbia","type":"literal","lang":"en"}],"http:\/\/purl.org\/dc\/terms\/description":[{"value":"This thesis describes the results of re-investigations into the solution behavior and interaction with molecular hydrogen of several triarylphosphine and -arsine complexes of ruthenium(ll) and ruthenium(III)\r\nThe complex RuCl\u2082(PPh\u2083)\u2083 was found to exist in N,N-dimethyl-acetamide (DMA) solutions in equilibrium with, a triply chloro-bridged bis(phosphine) dimer, I (L = DMA). Addition of chloride ion caused\r\n[Figure 1]\r\nsubstitution of the solvent to form an anionic dimer, I (L = CI ), and this is discussed, with respect to the stability of this bridging arrangement.\r\nIn the presence of added base, Proton Sponge\u00ae (1,8-bis(dimethyl-\r\namino)naphthalene) , the complexes RuX\u2082YL\u2082 (X = Y = CI, Br, or X = CI,\r\nBr, Y = 0\u2082CR; L = PPh\u2083, Ptol\u2083, or AsPB\u2083), [RuCl\u2082 (PPh\u2083)\u2082]\u2082,\r\n[RuCl(DMA)(PPh\u2083)\u2082(0\u2082CCH\u2082)]\u2082, and HRuCl(nbd)(PPh\u2083)\u2082 were found to react\r\nwith H\u2082 in DMA or toluene to give complexes of the form [H\u2082RuXL\u2082]\u2082\r\n(X = CI, Br). The ruthenium(III) product. [H\u2082RuCl(Ptol\u2083)\u2082]\u2082 has been\r\ncharacterized by analytical, molecular weight, \u00b9H- and \u00b3\u00b9P-n.m.r. methods and chemical reactions, and the data indicate an asymmetric dichloro-bridged dimer, II. The reaction of II with Ptol\u2083 in DMA to form HRuCl(Ptol\u2083)\u2083 has been studied kinetically; the results suggest that II is in equilibrium with the ruthenium(ll) dimer, [HRuClCPtol\u2083)\u2082]\u2082.\r\n\r\nThe reaction between RuCl\u2082(PPh\u2083)\u2083 and H\u2082 in DMA to form\r\nHRuCl(PPh\u2083)\u2083 has also been re-investigated. In the presence of a\r\nlarge excess of PPh\u2083, the reaction is believed to proceed by way of a\r\nbis(phosphine) monomer species, consistent with previous findings.\r\nHowever, in the presence of excess chloride, where the precursor\r\nexists as I (L = CI\u207b), spectrophotometry evidence indicates the\r\npresence of a long-lived intermediate. Investigations .of the v\r\ncorresponding bis (phosphine) complex, [RuCl\u2082(PPh\u2083)\u2082]\u2082, have made it\r\npossible to formulate the nature of the intermediate. Based mainly on \u00b3\u00b9P-n.m.r. and hydrogen uptake data, the intermediate is believed to be H\u2083Ru\u2082Cl\u2083(PPh\u2083)\u2084, a cogener of II. This allows for an overall scheme for the tris(phosphine) system under the conditions of excess chloride:\r\n\r\n[Figure 2] \r\nA similar scheme can be invoked to explain the reactivity of the bis-(phosphine) system.\r\nInvestigations of the corresponding reactivity toward H\u2082 of other bis(phosphine) systems for comparison led to the discovery of a new method of preparing carboxylato complexes. Based on a presumed, but not detected, alkyl intermediate, it was possible to prepare the dimer [RuCl(DMA)(PPh\u2083)\u2082(O\u2082CCH\u2082]\u2082, containing a bridging succinic acid linkage, and a series of RuCl(0\u2082CR)(PPh\u2083)\u2083 complexes. These have been characterized\r\nand their reactivity towards in toluene investigated. At concentrations sufficiently high for n.m.r. studies, the tris(phosphine) species react with to form HRuCl(PPh\u2083)\u2083 by a pathway involving initial formation of HRu(\u2082CR) (PPh\u2083)\u2083. The bis (phosphine) system, [RuCl(DMA)(PPh\u2083)\u2082(O\u2082CCH\u2082)]\u2082, forms the tetrahydride dimer, II, but the mechanism of formation could not be elucidated.\r\nThe nature of HRuCl(nbd)(PPh\u2083)\u2082 has be en examined; the species possesses the coplanar arrangement of metal, hydride, and olefin deemed requisite for olefin insertion reactions. Indeed, reaction with CO gives an acyl-dicarbonyl derivative, III, which results from consecutive olefin and CO insertion reactions. The HRuCl(nbd)(PPh\u2083)\u2082 complex reacts\r\n[Figure 3]\r\n\r\ncleanly with hydrogen in the absence of added base in toluene to form [H\u2082RuCl(PPh\u2083)\u2082]\u2082. Studies show that the reaction proceeds by a disproportionate\r\nreaction to form HRuCl(PPh\u2083)\u2083 and subsequent conproportionation with an unobserved phosphine deficient species to form the final product.","type":"literal","lang":"en"}],"http:\/\/www.europeana.eu\/schemas\/edm\/aggregatedCHO":[{"value":"https:\/\/circle.library.ubc.ca\/rest\/handle\/2429\/24282?expand=metadata","type":"literal","lang":"en"}],"http:\/\/www.w3.org\/2009\/08\/skos-reference\/skos.html#note":[{"value":"THE SOLUTION BEHAVIOR AND REACTIVITY OF SOME TRIARYLPHOSPHINE COMPLEXES OF RUTHENIUM By THOMAS WILLIAM DEKLEVA B.S. Clarkson College of Technology, 1978 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n the FACULTY OF GRADUATE STUDIES i n the Department of Chemistry We accept t h i s t h e s i s as conforming to the req u i r e d standard THE UNIVERSITY OF BRITISH COLUMBIA J u l y 1983. \u00a9 Thomas W i l l i a m Dekleva In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree a t the U n i v e r s i t y of B r i t i s h Columbia, I agree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and study. I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e copying o f t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the head of my department or by h i s or her r e p r e s e n t a t i v e s . I t i s understood t h a t copying o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be allowed without my w r i t t e n p e r m i s s i o n . Department o f CHEMISTRY The U n i v e r s i t y o f B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date July 26. 1983 6 (3\/81) ABSTRACT This t h e s i s describes the r e s u l t s of r e - i n v e s t i g a t i o n s i n t o the s o l u t i o n behavior and i n t e r a c t i o n w i t h molecular hydrogen of s e v e r a l t r i a r y l p h o s p h i n e and - a r s i n e complexes of r u t h e n i u m ( l l ) and ruthenium(III) The complex R u C l ^ P P h ^ ) ^ was found to e x i s t i n N,N-dimethyl-acetamide (DMA) s o l u t i o n s i n e q u i l i b r i u m with, a t r i p l y chloro-bridged bis(phosphine) dimer, I (L = DMA). A d d i t i o n of c h l o r i d e i o n caused 3 P h 3 p v \/ \\ x 0 1 L m...i.Ru,\u2014\u2014ci\u00bb\u2014Ru\u2022\u2022\u2022\u2022\u00bb\u00bb\u00bbPPh F h 3 ? ^ \/ ' ' C l ^ > > ^ P P h 3 (I) s u b s t i t u t i o n of the solvent to form an a n i o n i c dimer, I (L = CI ), and t h i s i s discussed, w i t h respect to the s t a b i l i t y of t h i s b r i d g i n g arrangement. I n the presence of added base, Proton Sponge\u00ae (1,8 - b i s ( d i m e t h y l -amino)naphthalene) , the complexes RuX,-,YL2 (X = Y = CI, Br, or X = CI, Br, Y = 0 2CR; L = PPh^, P t o l ^ , or AsPb^) , \u2022.[RuCl 2(PPh 3) 2] 2, {RuCl(DMA)(PPh 3) 2(0 2CCH 244 r 2, and HRuCl(nbd)(PPh 3) 2 were found to r e a c t w i t h H 2 i n DMA or toluene to give complexes of the form [H 2RuXL 2J 2 (X = CI, B r ) . The ruthenium(III) product. [ H 2 R u C l ( P t o l 3 ) 2 ] 2 has been 1 31 c h a r a c t e r i z e d by a n a l y t i c a l , molecular weight, H- and P-n.m.r. methods and chemical r e a c t i o n s , and the data i n d i c a t e an asymmetric d i c h l o r o - b r i d g e d dimer, I I . The r e a c t i o n of I I with P t o l ^ i n DMA to form HRuCl(Ptol 3), 3 has been studied k i n e t i c a l l y ; the r e s u l t s suggest that I I i s i n e q u i l i b r i u m w i t h the r u t h e n i u m ( l l ) dimer, [ H R u C l C P t o l ^ ) 2 ] 2 > - i i i -H P Ru-\\ \/ V H. P (II) The re a c t i o n between R u C l 0 ( P P h 0 ) 0 and H_ i n DMA to form HRuCl(PPh^)^ has also been re-investigated. In the presence of a large excess of PPh^, the reaction i s believed to proceed by way of a bis(phosphine) monomer species, consistent with previous f i n d i n g s . However, i n the presence of excess chloride, where the precursor ex i s t s as I (L = CI ), spectrophotometry evidence i n d i c a t e s the presence of a lo n g - l i v e d intermediate. Investigations .of the v corresponding b i s (phosphine) complex, [ RuCl 2(PPh 3) 2 n a v e made i t possible to formulate the nature of the intermediate. Based mainly on 31 P-n.m.r. and hydrogen uptake data, the intermediate i s believed to be H^Ru2Cl^(PPh^)^, a cogener of I I . This allows f o r an o v e r a l l scheme f o r the tris(phosphine) system under the conditions of excess chloride: 2 RuCl 0(PPh\u201e)_ + CI\" \u2022\u00ab w Ru 0Cl c(PPh\u201e)~ + 2 PPh, 2 $ i 2 5 3 4 3 Ru 0Cl_(PPhJ \" + H\u201e - HRu\u201eCl.(PPhJ ,\" + HC1 HRu 2Cl^(PPh 3)^\" + H 2 *~ H 3 R u 2 C l 3 ( P P h 3 ) ^ + C l \" H 3 R u 2 C l 3 ( P P h 3 ) ^ H 2 R u 2 C l 2 ( P P h 3 ) ^ + HC1 PPho H 2 R u 2 C l 2 ( P P h 3 ) ^ + PPh 3 2-^ 2 HRuCl(PPh 3) 3 - i v -A s i m i l a r scheme can be invoked to explain the r e a c t i v i t y of the b i s -(phosphine) system. Investigations of the corresponding r e a c t i v i t y toward of other bis(phosphine) systems f o r comparison l e d to the discovery of a new method of preparing carboxylato complexes. Based on a presumed, but not detected, a l k y l intermediate, i t was possible to prepare the dimer [RuCl(DMA) (PPh 3) 2(0 2CCH 2-}-}^, containing a bridging succinic acid linkage, and a series of RuCl(0 2CR)(PPh^)^ complexes. These have been character-iz e d and t h e i r r e a c t i v i t y towards i n toluene investigated. At concentrations s u f f i c i e n t l y high f o r n.m.r. studies, the tris(phosphine) species react with to form HRuCl(PPh 3) 3 by a pathway i n v o l v i n g i n i t i a l formation of HRu(02CR) (PPh^) y The bis (phosphine) system, [RuCl(DMA)(PPh 3) 2(0 2CCH 2 44 2 \u00bb forms the tetrahydride dimer, I I , but the mechanism of formation could not be elucidated. The nature of HRuCl(nbd)(PPh^) 2 has be en examined; the species possesses the coplanar arrangement of metal, hydride, and o l e f i n deemed r e q u i s i t e f o r o l e f i n i n s e r t i o n reactions. Indeed, reaction with CO gives an acyl-dicarbonyl d e r i v a t i v e , I I I , which r e s u l t s from consecutive o l e f i n and CO i n s e r t i o n reactions. The HRuCl(nbd)(PPh^) 2 complex reacts P C l ^ l CO CO I ^ C - R R = C H j| 7 9 P = PPh 3 P ( i l l ) c l e a n l y with hydrogen i n the absence of added base i n toluene to form [H 2RuCl(PPh 3) 2 ]2\u00bb Studies show that the reaction proceeds by a dispro-p o r t i o n a t e reaction to form H R u C l t P P h ^ and subsequent conproportion-- V -a t i o n with an unobserved phosphine d e f i c i e n t species to form the f i n a l product. - v i -TABLE OF CONTENTS;-; Page A b s t r a c t ............................................. ... \u2022\u2022 i i T a b l e o f c o n t e n t s - \u2022 v i L i s t o f t a b l e s .................................. x i i i L i s t o f f i g u r e s x v i A b b r e v i a t i o n s and symbols x x i v Acknowledgements x x v i i C h a p t e r 1. I n t r o d u c t i o n 1 C h a p t e r 2. E x p e r i m e n t a l 9 2.1 M a t e r i a l s 9 2.1.1 S o l v e n t s ...... . 9 2.1 .2 Gases. .......... 9 2.1-..3 O t h e r m a t e r i a l s 10 2.1.4 Ruthenium compounds.............. 10 2.1 ...4.1. D i c h l o r o t r i s ( t r i . p h e n y l p h o s p h i n e ) r u t h e n i u m ( l I ) . . 11 2.1.4.-2 D i c h l o r o t r i s ( t r i v g - t o l y l p h o s p h i n e ) s r u t h e n i u m ( l l ) 11 2.1..4.3 D i b r o m o t r i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( I I ) . . . 11 2.1.4.4- T r i c h l o r o b i s ( t r i p h e n y l p h o s p h i n e ) ( d i m e t h y l -a c e t a m i d e ) r u t h e n i u m ( I I I ) - D M A s o l v a t e 12 2.1 ..4.5 T r i c h l o r o b i s ( t r i ^ p _ - t o l y l p hosphine )\u2022( d i m e t h y l -a e e t a m i d e ) r . u t h e n i u m ( l I l ) * D M A s o l v a t e 12 2.1.4.6 T r i c h l o r o b i s ( t r i p h e n y l a r s i n e ) ( m e t h a n o l ) -r u t h e n i u m ( l l l ) 13 2.I..4....7 T r i b r o m o b i s ( t r i p h e n y l p h o s p h i n e ) ( m e t h a n o l ) -r u t h e n i u m ( l l l ) 13 - v i i -2.1 ..4.8 TribromGbis(triphenylarsine) (methanol)-ruthenium.(lll) 2.1.4.9 Dichlor.o (benzoato) bis (triphenyl phosphine)-ruthenium(III) ................. 14 2.1,.4...10' - The dichlorobis(triphenylphosphine)-ruthenium(TI) dimer.............. 14-2.1..4.11 Reaction' between [RuCl^PPh^) 2] 2 and Proton Sponge\u00ae ............ 15 2..I...4..12 DiT.y.-ehl'orotetrahydrido.tetrakis(triphenyl-phosphine)diruthenium(lll)\u20222DMA solvate 16 2.1'.,'..4'.13 .Di-u-chlorotetrahydridotetrakis(triphenyl-phosphine:) diruthenium(U'I) 17 2.1,.4 ..14 Dir-y-chlorotetrahydridptetraki s (\"tri-p_- t o l y l -phosphine)diruthenium(lll). ............. ^ 2.1 .4....15 Chlorohydridotri s(triphenyl phosphine )-ruthenium(ll)\u2022 toluene solvate.., 18 2.1 . 4 . 1 6 Chlorohydridotri s(trir-\u00a3-tolyl phosphine )-ruthenium(ll) ^9 2.1 ...4..17 u.-rSuccinato=dichlorobis(dimethylacetamide) -tetrakis(triphenylphosphine)diruthenium(ll)... 20 2.1.4.18 Carboxylatochlorotris(triphenylphosphine) ruthenium('II.) ^0 2.1 ..4..I.9 Dicarbonyldi:chlorotetrakis(triphenyl-phosphine)dirut'henium(ir) dicarboxylate 21 2.1.4-..20- Bis (carboxylase), bis (triphenyl phosphine)-ruthenium(ll) 21 2...I..4.2I Carboxy.la.tohydridotris( triphenylphosphine)-ruthenium ( l i ) . , . ^ - v i i i -2.1 .4..22'. D i h y d r i d ' o t e t r a k i s ( t r i - p _ - t o l y l p h o s p h i n e ) -r u t h e n i u m ( l l ) 24 2.1.4.23 Attempted pr e p a r a t i o n of d i h y d r i d o t r i s -(triphenylphosphine)ruthenium(II) 26 2.1 .4-.24' C h l o r o h y d r i d o ( n o r b o r n a d i e n e ) b i s ( t r i p h e n y l -phosphine)ruthenium(II) 27 2.1.4.25 D i c h l o r o ( n o r b o r n a d i e n e ) b i s ( t r i - p _ - t o l y l -phosphine)ruthenium(ll) 27 2.1 ..4.. 26- Chlorodicar.bonyl(nor.bornenoyl)bis(triphenyl-phosphine)ruthenium(II) 27 31 1 2.1..4...27 ' Other .complexes;- generation of a P{ H}-n.m.r. s h i f t t a b l e 28 2.2 Instrumentation.............................. 38 2.3 Procedure.for.monitoring .reactions of complexes 31 wit h using P-n.m.r. 40 2.4 Gas uptake apparatus and measurement 42 Chapter 3.. The nature of .dichloro.- and . d i b r o m o t r i s ( t r i p h e n y l -phosphine).ruthenium(ll) i n s o l u t i o n . . 46 3.1- I n t r o d u c t i o n . 46 3.2 Experimental, 50 3.2.1- Sample prep a r a t i o n and. manipulation 50 3.2.2 C a l c u l a t i o n s . 54 3.2..2...1 Determination of ...... . 54 3.2.2.2 Experiments concerning d i s s o c i a t i o n of phosphine l i g a n d s 56 3.2..2.3 Determination of by Job's method 57 3.2.3 3 1P{ 1H}-N.m.r s t u d i e s 59 - i x -3.3 R e s u l t s : 60 3.4 D i s c u s s i o n 83 Chapter- 4. C h a r a c t e r i z a t i o n 1 and r e a c t i v i t y of d i - y - c h l o r o - \u2022. tetrahydridot.etrakis(-triaryl.phosphine)di- ; ruthenium (III)..,.....,... ,. 102 4.1' I n t r o d u c t i o n ...... ..'.\u2022\u2022\u2022.. \u2022... \u00bb................................. 102 4 .2 Data . -. 107 4.2.1 Precursors'.for uptake experiments \u2022 107 4 . 2 . 2 'Gas uptake and e v o l u t i o n 110 4 . 2 . 3 . Pre p a r a t i o n , of complexes 110 4\u201e2i.4 \u2022\u2022. N..-.m\u00abr.- spectroscopy 118 4.2.4.I 1H-N.m.r. . 118 4. .2 .4v2. 31P-N.,m.r. ..... . 121 4 \u201e 2 . 5 : Chemical r e a c t i o n s 125 A . 2 . 5 \u2022 1 .Hydrogen c h l o r i d e 125 4 .2 .5 . i2 2,2\u00bb-Bipyridine ........ .. 129 4.2.-5.3 Carbon monoxide ..................... 130 4 . 2 . 5 . 4 Phosphines.. ......... 1 32 4 .3 D i s c u s s i o n ............... 137 Chapter '.5... -The re a c t i o n , of \u2022 d i c h l o r o t r i s ( t r i p h e n y l p h o s p h i n e ) -ruthenium.(ll) with., molecular hydrogen i n dimethylacetamide s o l u t i o n 156 5.1 I n t r o d u c t i o n 156 5.2 A reinvestigation.-, of .the: r e a c t i o n of R u C l ^ P P h ^ ^ w i t h .H^ i n the. presence- of excess PPh^ i n DMA to form. HRuCl(PPh 3) 3 158 5.2...1. Introduction'and aim of work.............. 158 - X -5 . 2 . 2 E x p e r i m e n t a l a n d r e s u i t s 161 5 . 2 . 3 D i s c u s s i o n . . . . . . 1 6 6 5 . 3 T h e r e a c t i o n o f R u G l ^ P P h ^ ) ^ w i t h H 2 i n t h e p r e s e n c e , o f . e x c e s s . c h l o r i d e i n DMA t o f o r m H R u C l ( P P h 3 ) 3 \u2022 1 7 0 5 . 3 . 1 . I n t r o d u c t i o n a n d a i m o f w o r k . . . . . 1 7 0 5 . 3 . 2 P r e l i m i n a r y s t u d i e s . . . . . . . . . . . . . 174-5 . 3 . 3 R e s u l t s a n d i n t e r p r e t a t i o n o f t h e k i n e t i c d a t a o b t a i n e d f o r t h e r e a c t i o n i n d r y DMA w i t h a d d e d P P h 3 t o f o r m H R u C l t P P h ^ 1 8 8 5 - 4 I n v e s t i g a t i o n s i n t o * t h e r e a c t i v i t y o f [ R u G l 2 ( P P h 3 > 2 ] 2 w i t h m o l e c u l a r h y d r o g e n i n t h e a b s e n c e o f a d d e d P P h 3 -.. 2 0 0 5.4. . . 1 V i s i b l e s p e c t r o s c o p y a n d g a s u p t a k e s 201 5 . 4 . 2 N . m . r . s t u d i e s .... 2 0 9 5.4-2....1 I n t o l u e n e - d g 2 0 9 5 . 4 . . 2 . 2 S t u d i e s i n D M A \/ t o l u e n e - d g m i x t u r e s 214-5 i 4 > 3 . D i s e u s M o n 2 2 5 C h a p t e r 6 v P r e p a r a t i o n o n r e a c t i v i t y o f some c h l o r o c a r b o x y l a t o -c o m p l e x e s o f r u t h e n i u m ( I I ) . . . . . 2 3 5 6 . 1 I n t r o d u c t i o n 2 3 5 6 . 2 P r e p a r a t i o n o f c o m p l e x e s 2 3 9 6 . 2 . 1 S y n t h e s e s - ' \u00a9 f p a r e n t c o m p l e x e s . . . . . . . . . . 2 3 9 6 . 2 . 2 R e a c t i o n s , 241 6 . . 2 . 2 . 1 R e a c t i o n s w i t h C O . . 241 6 . 2 . 2 . 2 ' R e a c t i o n w i t h P M e 3 2 4 2 6 , . 2 . 2 . 3 R e a c t i o n w i t h H C 1 . . . 2 4 3 - x i -6.3 Characterization of the complexes .., 244 6.3.1\" Elemental analyses ... 244 6..3.2 Infrared spectra .................. 244 6.3.3 1H-N.m.r. 251 6.3.4 31P{1H}-N.-m.r. ... , 255 6.4 Furthe-r.general discussion................. 261 6.5 Reactions- of the .[P.uCl(DMA) ( ? p v< 3) 2^ \u00b02 C C H2\"^2 . and RuCl:(02CRHPPhy).3 -systems with hydrogen 270 6.5-1 ' Visible., spectroscopy, and gas -uptakes 271 6.5-2 N.m.r,. studies 277 6.5.2.1 = On.' [RuCl^DMA^(PPh 3) 2(0 2CCH 2-)^ \u2022\u2022\u2022 \u2022 277 6..5-2..2 \u2022< On- RuCl(.0oCC,H-) (PPh\u201e) _. 283 2 o 5 3 3 6.5.3 Discussion \u2022 of-the.hydrogenation reactions 293 6.6: Discussion, of the i d e n t i t y and.reactivity with hydrogen, of the \u2022 IIRuC.'! (PPh.^) ^ complex i n benzene or toluene 295 Chapter 7- Characterization and ..-reactions, of\u2022-. chlorohydrido-(norbornadiene )bis.( t r i phenyl phosphine) -ruthenium ( I I ) . 302 7.1 Introduction .......................... . 302 7.2 Preparation and-characterization'.. 303 7.3 Reactions. ........... . 305 7.3-1 Reactions with H;2 ....... 305 7.3.'2' Reaction with. GO 313 7.3.3' Reaction with GO^....... 323 7.3.4 Attempted preparation, of HRu^GGI^) (nbd) ( P P h ^ . 323 7-4 Discussion. ..................... 324-- x i i -Chapter 8 . . General summary and recommendations f o r future work. 3 3 5 References 34-3 Appendices 3 5 7 - x i i i -L I S T OF T A B L E S T a b l e 31 1 I I - 1 P { H } - N . m . r . . s h i f t d a t a f o r some c a r b o n y l Page, c o m p l e x e s , 29 31 I I - 2 A c o m p a r i s o n o f P c h e m i c a l s h i f t s a n d c r y s t a l l o -g r a p h i c a l l y d e t e r m i n e d b o n d l e n g t h s f o r some r u t h e n i u m - p h o s p h i n e c o m p l e x e s 37 I I I - 1 S p e c t r a l c h a n g e s a t 4-80 nm a c c o m p a n y i n g t h e a d d i t i o n . o f P P h ^ t o s o l u t i o n s o f R u C l ^ P P h ^ ) ^ i n t o l u e n e . . 61 I I I - 2 S p e c t r a l c h a n g e s a t 4 7 5 nm a c c o m p a n y i n g t h e a d d i t i o n o f P P h 0 t o s o l u t i o n s o f R u B r \u201e ( P P h 0 ) 0 i n t o l u e n e . . . 61 I I I - 3 S p e c t r a l c h a n g e s a t 4 7 8 nm a c c o m p a n y i n g t h e a d d i t i o n o f P P h 0 t o s o l u t i o n s o f R u C l 0 ( P P h J 0 i n DMA ' 68 I I I - 4 S p e c t r a l c h a n g e s a t 4 7 8 nm u s e d f o r J o b ' s m e t h o d o f c o n t i n u o u s v a r i a t i o n f o r d e t e r m i n a t i o n o f K . . . . 71 4 I I I - 5 C a l c u l a t e d . f o r m a t i o n c o n s t a n t s , K , a n d K r , f o r 4 5 R u \u201e C l c ( P P h J . \" u s i n g t h e d a t a i n T a b l e I I I - 4 \"72 <\u2022 b 3 4 I I I - 6 D e t e r m i n a t i o n o f . . . . . . . . . . ' 7 6 I I I - 7 : S p e c t r a l cHang .es ' a t ; -6 -10 n m , \" a c c o m p a n y i n g t h e a d d i t i o n o f P P h _ t o s o l u t i o n s ' o f R u B r 0 ( P P h 0 ) \u201e i n DMA 77 I I I - 8 E f f e c t s o f s m a l l e r r o r s i n [ P P h ^ ] , A b s , a n d A ^ o n c a l c u l a t e d v a l u e s o f K^--- . - 7 8 I I I - 9 3 1 P { ' - H j - N . m . r . p a r a m e t e r s f o r [ R u C l ^ P P h ^ ) 2 ] 2 i n t o l u e n e a n d DMA 81 - x i v -111-10- Degree of d i s s o c i a t i o n f o r R u X ^ P P h ^ at 30\u00b0C i n toluene .as a function, of concentration 88 31 1 III -11 P{ H}-N.m..r. s p e c t r a l parameters f o r compounds co n t a i n i n g the t r i - u - c h l o r o d i r u t h e n i u m framework.. 95 III-1-2 Selected, base parameters.... 99 IV- 1 E..s..r. parameters of some monomeric ruthenium ( i l l ) compounds at -196\u00b0C. 109 IV-2 Hydrogen uptake data f o r ruthenium bis(phosphine) and -(arsine.). precursors.....*. 111 IV-3 Gas e v o l u t i o n data to confirm the stoichiometry [H 2RuClP. 2] 2 (P = PPh 3\u201e P t o l ) 1 U IV-4- N.m.r. parameters f o r [ H 2 R u X L 2 ] 2 complexes... 119 IV-5' K i n e t i c data f o r the r e a c t i o n between [ H 2 R u C l ( P t o l 3 ) 2 ] 2 and P t o l i n DMA at 30\u00b0C 135 IV-6 V a r i a t i o n of i n i t i a l r a t e w i t h t o t a l [Ru] using the. data, of reference 1 4-6.. 154 V-1 E f f e c t of adding PPh^ to DMA; volume c o r r e c t i o n and.hydrogen \u2022solubility....................... 162 V-2 Reaction of RuCl 2(PPh ). i n DMA with Hg. Dependence on concentrations on concentrations of PPh 3 and E ^ . 163 V-3 I n i t i a l r e s u l t s f o r the f i n a l e x t i n c t i o n c o e f f i c i e n t s at 520 nm f o r r e a c t i o n 5.15 as a function,.of [H 2 ] 175 V- 4 P r e l i m i n a r y r e s u l t s using pure DMA f o r reaction,. 5.15 a t 30\u00b0C 180 V-5 Rate ;data f o r r e a c t i o n 5.15 i n the presence of added. PPh^. . 183 V-6 E f f e c t on k ^ of adding H o0 t o . r e a c t i o n 5.15 187 - X V -V-7 K i n e t i c data f o r the reaction between and Ru0Cl_('PPh\u201e) ~ i n the presence of PPh Q i n DMA to form HRuCl(PPh 3) 3 189 VI-1 Elemental, analyses for some succinic acid derivatives..... 247 VI-2 Infrared data for carboxylate derivatives 249 1 VI-3 H-N.m.r. data f o r carboxylate . derivatives 252 31 VI-4 P-N-.m.r.. data f o r carboxylate d e r i v a t i v e s . . 256 VI-5 Hydrogen uptake stoichiometries f o r chloro-carboxylate systems when PPh^ :. Ru > 3 273 31 1 VI-6 P{ H}^N..m.r. parameters for the complexes with the apparent .stoichiometry Ru^Cl^O^GR) (PPh^)^.... 290 VI-7 Reported properties f o r the Schram dimer, [HRuCl(TPh 3) 3]. 2, and Wilkinson's product, HRuCl(PPh 0.) 0'C,H, ., 296 3 3 o 6 1 13 1 VII-1 Measured H and. G{ H}-rn..m.r. parameters f o r RuSl.(G0\u00bbC- 7H 9)(C0). 2(PPh 3) 2 i n 319 VII-2 Coupling constants. J(H-H) f o r RuCl(C0..C 7H 9)(C0) 2(PPh- 3) 2 320 - x v i -LIST OF FIGURES Figure\" . Page 1 2.1-': H i g h - f i e l d region of the H-n.m.r. spectrum showing the hydride of H ^ u t P P h ^ i n C^D^ 25 2.2 I n f r a r e d spectrum of. HRu^CCgH^) (PPh^) 2\u00bb (C.HcC00H) '\u2022- 34 6 5 2.3 P l o t of c r y s t a l l o g r a p h i c a l l y determined bond 31 lengths vs.. P chemical. s h i f t s 36 2.i Schematic r e p r e s e n t a t i o n of the anaerobic c e l l s . . 39 2.5 Schematic r e p r e s e n t a t i o n of a constant pressure gas uptake apparatus................... , 43 3.1 Absorbance changes accompanying the a d d i t i o n of PPh^ to s o l u t i o n s of. R u C l ^ P P h ^ i n toluene 62 3.2 P l o t s of K. (calculated^ .-'Iv-s-;--.'rAt..J.(-as'siamed.) - for:\":the 1 o d i s s o c i a t i o n of RuCl.^CPPh^)^ i n toluene 63 3.3 P l o t s of K 0 ( c a l c u l a t e d ) , vs.. A (assumed) f o r the 2 \u2014 o d i s s o c i a t i o n of R u C l ^ P P h ^ ) ^ i n toluene 64 3.4 Absorbance changes accompanying the a d d i t i o n of PPh 0 to s o l u t i o n s of R u B r 0 ( P P h J 0 i n toluene ' 65 3.5 P l o t s of K. ( c a l c u l a t e d ) vs. A (assumed) f o r the 1 \u2014 o d i s s o c i a t i o n of RuBrg^Ph^)^ i n toluene 66 3.6 P l o t s of K n ( c a l c u l a t e d ) vs. A (assumed) f o r the 2 \u2014 o d i s s o c i a t i o n of RuBr^CPPh-^^ i n toluene 67 3.7 Absorbance changes accompanying the a d d i t i o n of PPh^ to s o l u t i o n s of R u C l ^ P P h ^ i n DMA 68 3.8 P l o t s of K\u201e ( c a l c u l a t e d ) vs. A (assumed) f o r the 1 \u2014 o d i s s o c i a t i o n of R u C l 0 ( P P h Q ) , i n DMA 69 - x v i i -3 . 9 Plots of K\u201e. (calculated) vs:. A (assumed) for the 2 \u2014 o dissociation of R u C l ^ P P h ^ in DMA... 7 0 3 . 1 0 Plots of absorbance vs. ruthenium concentration when DMA solutions of RuClgtPPh^)^ were diluted with DMA and DMA solutions of AsPh.Cl 2H_Q 73 4 <\u2022 3 . 1 1 Continuous variation .plots for the complex formed \".; between [RuCl 2(PPh 3) 2 J 2 and chloride i n DMA 74-3 . 1 2 Absorbance. changes accompanying the reaction given-in equation 3 . .9 . . . . . . 75 3 . 1 3 31P.{1H}-N.m..rv spectra of Ru2Cl^(DMA) ( P P h ^ as a function of temperature............... 8 0 3.U- 31P{1H}-N.m..,r.. spectra of Ru_Cl_(PPhJ7 in DMA\/ <~ J 3 4 toluener-dg as a function of temperature.... 82 3 . 1 5 . P I ots \u2022 of K'v ^ calculated) -vs.-*\"A \" (assumed) for the dissociation of RuCl^PPh^)^ in benzene 85 3 . 1 6 . Plots of K .\u201e (calculated)., vs.. A (assumed) for the 2 \u2014 o dissociation of RuC-l^PPh^)^ in benzene 86 3 . 1 7 Mole^ratio plot for the reaction of chloride with . R-uG-I^-PP^)^ using- the data in reference 6 a 93 4 . 1 - Observed e..s.^ r. signal for one sample of [H 2RuGlCPPh 3) 2] 2 116 4 . 2 Visible spectra of [B^RuClCPPh^)2]? 1 1 7 4 - 3 1H-N.m.r. spectrum of [H 2RuCl(Ptol 3) 2J 2 at 25\u00b0C.. . 121 1 4 . 4 High-field region of the H^n.m.r. spectrum of [H 2RuCT(Ptol 3) 2] 2 in CD2C'l2 at 400 MHz as a . function-of temperature.. 122 4 . 5 3 1P- N.m.r.. spectra .of [.HgRuCKPtol^)2 ] 2 at 30\u00b0C .. 124 - X V l l l -4.6 3 1 P { ' 1 H } . N . m . r . s p e c t r a o f [ H 2 R u C l ( P t o l 3 ) 2 ) 2 a s a f u n c t i o n o f . t e m p e r a t u r e i n t o l u e n e - d Q 1 2 6 o 4 . 7 3 1 P ^ N i i - m . . r . s p e c t r a o f [ H 2 R u C l ( P t o l 3 ) 2 l 2 -in.CDgClg. a t - 9 5 \u00b0 C . . 1 2 7 31 1 4 . 8 S i m u l a t e d 3 P { H}=r n . m . r . s p e c t r u m o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 i n s l o w e x c h a n g e . 1 2 8 31 1 4 .9 P { H } - N . . m . r . s p e c t r u m o f t h e r e a c t i o n p r o d u c t s o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 . . w i t h D M A - H C 1 . 1 2 9 31 1 4.10 P { H} - N . m . r . s p e c t r u m o f t h e r e a c t i o n p r o d u c t s o f [ H 2 R u C l ( P P h 3 ) 2 ] 2 w i t h CO i n C ^ 131 4 .11 S p e c t r a l c h a n g e s a c c o m p a n y i n g t h e r e a c t i o n o f [ H 2 R u C r ( P t o l 3 ) 2 ] 2 w i t h P t o l 3 i n DMA. u n d e r H 2 1 3 3 4...12 D e p e n d e n c e o f o n [ P t o l . ^ ] f o r t h e r e a c t i o n o f [ H 2 R u C l ( ' P t o l 3 ) 2 ] 2 w i t h P t o l 3 i n DMA 1 3 4 4.13 D e p e n d e n c e , o f k v o n [H_ J f o r t h e r e a c t i o n o f . o b s L 2 [ H 2 R u C l ( ' P t o l 3 ) 2 ] 2 w i t h - P t o l i n DMA 1 3 6 4 . 1 4 \u2022 C r y s t a l s t r u c t u r e o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 a n d s e l e c t e d b o n d a n g l e s a n d d i s t a n c e s 1 3 8 4 . 1 5 P r o p o s e d s l o w e x c h a n g e s t r u c t u r e f o r t . [ H 2 R u C l ' ( P t o l 3 ) 2 ] 2 , . i n c l u d i n g p o s i t i o n s o f t h e h y d r i d e s a n d n . m . r . a s s i g n m e n t s . . 1 4 2 31 4 . 1 6 S i m u l a t e d P ^ n . . m . . r . s p e c t r a o f W i l k i n s o n ' s t e t r a n u e l e a r s p e c i e s . . . . . . ; . . . ' ; 1 . . . . . . . . . . 1 4 5 5 . 1 ' D e p e n d e n c e o f k o n [ P P h 0 ] i n DMA 1 5 9 o b s 1 3 5 . 2 D e p e n d e n c e o f k ^ o n [H~ 2 ] i n DMA a t 2 5 \u00b0 C 1 5 9 5 . 3 R e p r e s e n t a t i v e s p e c t r a l c h a n g e s a c c o m p a n y i n g t h e r e a c t i o n o f R u C l 2 ( P P h 3 ) ; 3 i n t h e p r e s e n c e o f e x c e s s P P h 3 w i t h . H 2 i n DMA. . . , 1 6 4 - x i x -5.4 Dependence o f k ^ o n P
o n e e q u i v a l e n t o f D M A - H C 1 . p e r d i m e r i n D M A \/ t o l u e n e - d g . . 224. 5 . 3 0 P r o p o s e d s t r u c t u r e f o r t h e A B C D . c o m p l e x 2 2 9 6 . 1 I n f r a r e d s p e c t r a o f s u c c i n i c a c i d d e r i v a t i v e s . . . . 245 6 . 2 I n f r a r e d s p e c t r a o f R u C l C O g C C ^ ) (PPh .^ ) , R u C l j 0 o C C . H j ( P P h J o > ; a n d R u C l ( 0 o C C H , ) ( P P h J . . . . 2 4 6 2 . 2 o p 3 2 2 j5 5 3 6 . 3 1 H - N . m . r . s p e c t r u m o f [ R u C l C - P M e ^ ) ^ ( O ^ C H ^ H ^ i n C 6 D 6 2 5 K 6 . 4 3 1 P { 1 H } . - : N . m . r . s p e c t r u m o f R u C l ^ C C ^ ) ( P P h ^ ) ^ i n D M A \/ t o l u e n e - d g . . . . . 2 6 0 6 . 5 3 1 P { 1 H } - N . m . r . s p e c t r a o f [ R u C l ( D M A ) ( P P h 3 ) 2 ( 0 2 C C H 2 4 } - 2 i n CD C l 2 2 6 0 6 . 6 I n f r a r e d s p e c t r u m o f W a n g ' s ' o r t h o m e t a l l a t e d p r o d u c t 2 6 2 31 1 6 . 7 P { H } - N . m . . r . s p e c t r u m o f a s o l u b l e d i a c i d p r o d u c t i n t o l u e n e - d 2 6 4 o 31 1 6 . 8 P{\" H } - N . . m . r . s p e c t r u m o f W a n g ' s o r t h o m e t a l l a t e d p r o d u c t . i n a c e t o n e - d ^ \/ D M A , 2 6 5 31 1 6 . 9 Two P { H } - n . m . . r . s p e c t r a o f r e a c t i o n m i x t u r e s r e s u l t i n g w h e n H R u C l C ' P P h ^ ) ^ a n d e x c e s s m a l e i c a c i d w e r e s h a k e n o r s t i r r e d i n DMA . . 2 6 8 - x x i i -6 . 1 0 V i s i b l e s p e c t r a l c h a n g e s a c c o m p a n y i n g t h e r e a c t i o n b e t w e e n . . R u C l ( 0 _ C C , H r ) ( P P h o ) o a n d H\u201e i n t o l u e n e 2 7 2 2 O o j ; 2 6 . 1 1 S p e c t r a l c h a n g e s a c c o m p a n y i n g t h e . r e a c t i o n b e t w e e n H 2 a n d H R u C l ( P t o l 3 ) i n t o l u e n e 276-31 1 6 . 1 2 P { H}-N..m.r.. s p e c t r a o f t h e s o l u t i o n s g e n e r a t e d w h e n [ R u C l ( D M A ) ( P P h 3 ) 2 ( 0 2 C C H 2 - H ~ 2 w a s s h a k e n w i t h H 0 i n t o l u e n e - d 0 2 8 0 2 o 31 1 6 . 1 3 P { H}-rN.m.r.. s p e c t r u m o f t h e s o l u t i o n r e s u l t i n g w h e n . R u ( 0 2 C C H 3 ) 2 ( P P h 3 ) 2 a n d ( R u C l 2 ( P P h 3 ) 2 ] 2 w e r e m i x e d i n to luene-rdg 2 8 2 6 .14- H i g h - f i e l d . H - n . m . . r . s p e c t r a f o r t h e r e a c t i o n b e t w e e n . R u C l C O ^ C ^ ) ( P P h 3 ) 3 a n d H 2 i n 2 8 4 6 . 1 5 P-N . m . r . . s p e c t r a o f - t ' o l u e n e - : d g \/ - s o l u t i o n s o f R u C l ( 0 \u201e C C , H r ) ( P P h J \u201e a f t e r b e i n g s h a k e n w i t h H \u201e . . . 2 8 6 2 o o i 3 2 6 . 1 6 3 1 P { 1 H}-N : v m . . r . s p e c t r a o f . R u ^ l ^ O ^ C ^ ) ( P P h 3 ) . . 2 8 9 6 . 1 7 1 H - N . m . r . . s p e c t r a o f H R u C l . ( P t o l 3 ) ^ u n d e r H 2 301 7 . 1 1 H - N . m . . r . s p e c t r u m o f H R u C l ( n b d ) ( P P h 3 ) 2 3 0 4 7 . 2 H y d r o g e n u p t a k e p l o t s f o r t h e r e a c t i o n b e t w e e n H 2 a n d H R u C l ( n b d ) ( P P h 3 ) 2 i n DMA a n d t o l u e n e 3 0 6 7 . 3 A b s o r b a n c e c h a n g e s w i t h t i m e f o r t h e r e a c t i o n b e t w e e n H R u C l ( n b d ) ( P P h 3 ) 2 a n d H 2 i n t o l u e n e 3 0 7 7 . 4 H-N .m . r . . s p e c t r a l c h a n g e s w h e n H R u C l ( n b d ) ( P P h 3 ) 2 w a s s h a k e n w i t h H 2 i n C ^ D ^ 3 0 9 31 1 7 . 5 P { H}.-rN.m..r.. s p e c t r a l c h a n g e s f o r t h e r e a c t i o n b e t w e e n H R u C l ( n b d ) ( P P h 3 ) 2 a n d H 2 i n 3 1 2 31 1 7 . 6 P { H}.-N.m..r. s p e c t r a l c h a n g e s f o r t h e r e a c t i o n b e t w e e n H R u C l ( n b d ) ( P P h ? ) 9 i n t o l u e n e - d H a t - 6 0 \u00b0 C . 3 1 4 - x x i i i -7 . 7 C h a n g e s i n \" \" p - n . m . r . s p e c t r u m a t 3 0 \u00b0 C w h e n H R u C l ( n M ) ' ( P P h J 0 w a s s h a k e n w i t h CO i n ' C . D , 3 1 6 3 2 6 6 7..8 I n f r a r e d s p e c t r u m o f R u C l ( C 0 . C ^ ) ( C 0 ) 2 ( P P h 3 ) 2 3 1 7 7.9 1 H - N . . m . r . s p e c t r u m o f R u C l ( C 0 . . C 7 H 9 ) ( C 0 ) 2 ( P P h 3 ) 2 . . . 3 1 8 7 . 1 0 A p p a r e n t , s k e l e t a l a r r a n g e m e n t o f t h e a c y l m o i e t y i n R u C l ( C 0 . C 7 H 9 ) ( C 0 ) 2 ( P P h 3 ) 2 321 7 . 1 1 1 3 C { 1 H } - N . m . r . spectrum o f RuCKCO-.C^) ( C 0 ) 2 ( P P h 3 ) 2 . 3 2 2 - x x i v -A B B R E V I A T I O N S AND S Y M B O L S T h e f o l l o w i n g l i s t o f a b b r e v i a t i o n s a n d s y m b o l s w i l l b e e m p l o y e d i n t h i s t h e s i s . S. a n g s t r o m ( s ) A b s a b s o r b a n c e , . A . , i n i t i a l a b s o r b a n c e o A f i n a l a b s o r b a n c e oo a t m a t m o s p h e r e ; 1 a t m = 760 mm H g : b r b r o a d d d a y ( s ) ; d o u b l e t DMA : .N,.- N ^ d i m e t h y l a c e t a m i d e , C H C O . N ( C H ) 2 DMA* H G I N , , N - d i m e t h y l a c e t a m i d e h y d r o c h l o r i d e e . s . r . e l e c t r o n s p i n r e s o n a n c e g g r a m g . l . c . g a s - l i q u i d c h r o m a t o g r a p h y h h o u r ( s ) H z . . h e r t z , c y c l e s p e r s e c o n d i . r . i n f r a r e d , ( s p e c t r o s c o p y o r s p e c t r u m ) J c o u p l i n g c o n s t a n t , , i n H z k r a t e c o n s t a n t K e q u i l i b r i u m c o n s t a n t -1 -1 k , p s e u d o f i r s t o r d e r r a t e c o n s t a n t , M s o b s -L l i g a n d l i t . l i t e r a t u r e v a l u e ( s ) l o g n a t u r a l l o g a r i t h m m m u l t i p l e t M m o l a r . , , m o l e s p e r l i t e r Me m e t h y l , -CE^ m i n m i n u t e mL m i l l i l i t e r m . p . m e l t i n g p o i n t n b d n o r b o r n a d i e n e nm n a n o m e t e r s n . m . r . . n u c l e a r m a g n e t i c r e s o n a n c e o ( s u b s c r i p t ) i n i t i a l ; , a t z e r o t i m e P p h o s p h i n e . , u s u a l l y P P h ^ o r P t o l ^ '\u2022\u2022 P h ,. '. : \u2022. p h e n y l , - C ^ P P h ^ t r i p h e n y l p h o s p h i n e , P ( G ^ E ^ ) ^ ppm p a r t s . p e r m i l l i o n P P N C I \u2022 U - N i t r i d o b i s C ' t f i p h e n y l - p h o - s p h o r u s ) c h l o r i d e [N(PPh 3) 2][Cl]' (a P . S . P r o t o n S p o n g e 1, 8 - b i s ( d i m e t h y l a m i n o ) -n a p h t h a l e n e p . s . i . p o u n d s p e r s q u a r e i n c h P t o l 0 t r i ( p - t o l y l ) p h o s p h i n e . , P ( \u00a3 - C , H , C H _ ) _ P ^ t o t a l p r e s s u r e q q u a r t e t R a l k y l o r a r y l g r o u p s s e c o n d ( s ) ; s i n g l e t S s o l v e n t t t i m e ; t r i p l e t T ( s u b s c r i p t ) t o t a l - x x v i -THF t e t r a h y d r o f u r a n , , OCHgCH CHgCHg X a n i o n i c l i g a n d 6 c h e m i c a l s h i f t i n ppm d o w n f i e l d f r o m \u2022 s t a n d a r d A d i f f e r e n c e X, A w a v e l e n g t h , w a v e l e n g t h o f max imum a b s o r b a n c e max V f r e q u e n c y , cm V a s y m m e t r i c s t r e t c h i n g f r e q u e n c y V s y m m e t r i c s t r e t c h i n g f r e q u e n c y s [ ] c o n c e n t r a t i o n , M 1 { H} - - b r o a d b a n d - p r o t o n d e c o u p l e d ; i n g e n e r a l , n u c l e i e n c l o s e d i n b r a c k e t s a r e d e c o u p l e d - 1 -1 e m o l a r e x t i n c t i o n c o e f f i c i e n t , M cm - x x v i i -ACKNOWLEDGEMENTS. I w i s h t o t h a n k P r o f e s s o r B . R . J a m e s f o r h i s e n c o u r a g e m e n t t h r o u g h o u t t h e c o u r s e o f t h i s w o r k . I w o u l d a l s o l i k e t o t a k e t h i s o p p o r t u n i t y t o t h a n k t h e m e m b e r s o f t h e g r o u p f o r m a k i n g t h e s e y e a r s e n j o y a b l e a n d p a r t i c u l a r l y I . T h o r b u r n f o r h e l p f u l d i s c u s s i o n s t h r o u g h o u t . I w i s h t o t h a n k P r o f e s s o r M . F r y z u k f o r o b t a i n i n g t h e P - n . m . r . s p e c t r a s h o w n i n F i g u r e 4 . 7 o f t h i s w o r k , a n d e x p r e s s my g r a t i t u d e t o t h e m e m b e r s o f t h e a n a l y t i c a l . , e l e c t r i c a l . , g l a s s b l o w i n g , m e c h a n i c a l , a n d n . m . r . s t a f f s f o r t h e i r e x p e r t i s e . F i n a l l y , f i n a n c i a l s u p p o r t f r o m t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a ( 1 9 7 8 - 1 9 8 0 ) a n d t h e 1 I z a a c - . W a l t o n - K - I l l a m . M e m o r i a l F o u n d a t i o n ( 1 9 8 0 - 1 9 8 2 ) b y w a y o f t h e i r P r e - D o c t o r a l F e l l o w s h i p s i s g r a t e f u l l y a c k n o w l e d g e d . -1-C H A P T E R 1. I N T R O D U C T I O N . T h e ' i m p o r t a n c e 1 o f t h e i n t e r a c t i o n s b e t w e e n h y d r o g e n a n d t r a n s i t i o n m e t a l c o m p l e x e s f o r b o t h s t o i c h i o m e t r i c a n d c a t a l y t i c r e a c t i o n s i n o r g a n i c a n d o r g a n o m e t a l l i c c h e m i s t r y i s r e f l e c t e d i n t h e v a s t l i t e r a t u r e w h i c h d e a l s w i t h t h i s s u b j e c t . M o l e c u l a r h y d r o g e n , H ^ , i n t e r a c t s w i t h t h e s e c o m p l e x e s , u s u a l l y c a u s i n g r u p t u r e o f t h e H - H b o n d a n d f o r m a t i o n o f m e t a l h y d r i d e b o n d s . I n s i t u a t i o n s w h e r e c o n c o m i t a n t a c t i v a t i o n o f o r g a n i c s u b s t r a t e s c a n o c c u r , c a t a l y t i c h y d r o g e n a t i o n o f t e n r e s u l t s . B y s t u d y i n g r e a c t i o n k i n e t i c s , a s w e l l a s t h e i n t e r m e d i a t e a n d p r o d u c t h y d r i d e s , m e c h a n i s t i c d e t a i l s o f h o m o g e n e o u s l y c a t a l y z e d h y d r o g e n a t i o n r e a c t i o n s c a n b e e l u c i d a t e d . S e v e r a l e x c e l l e n t m o n o g r a p h s a r e a v a i l a b l e w h i c h g i v e f a i r l y c o m p r e h e n s i v e t r e a t m e n t o f t h e a c t i v a t i o n o f h y d r o g e n a n d i t s a d d i t i o n t o u n s a t u r a t e d s u b s t r a t e s 5 ~ 8 S e v e r a l s t u d i e s i n t h i s l a b o r a t o r y h a v e c e n t e r e d a r o u n d d e t e r m i n a t i o n o f t h e m e c h a n i s m s i n v o l v e d w i t h o l e f i n h y d r o g e n a t i o n r e a c t i o n s i n DMA u s i n g t h e c a t a l y s t s H R u C l C P P h ^ ) y a n d m o r e r e c e n t l y [ H R u C l C P P h ^ ) ^ ] 2 * B o t h s y s t e m s . have b e e n e x t e n s i v e l y r e v i e w e d 1 ' 9 , a l t h o u g h some a d d i t i o n a l i n t r o d u c t i o n t o t h e b i s ( p h o s p h i n e ) s y s t e m i s p r e s e n t e d i n S e c t i o n 4...1 o f t h i s t h e s i s . T h e c h e m i s t r y o f t h e s e s y s t e m s h a s b e e n d e s c r i b e d i n t e r m s o f m o n o m e r i c r u t h e n i u m h y d r i d e o r a l k y l s p e c i e s w h i c h a r e p r e s u m e d t o b e s t a b i l i z e d b y t h e c o o r d i n a t i o n o f s o l v e n t DMA., w h i c h i s k n o w n t o b e a g o o d d o n o r l i g a n d 1 0 . - 2 -T h e r e s u l t s o f a s t u d y i n t o t h e r e a c t i o n b e t w e e n R u C l _ ( P P h _ ) _ a n d H 2 i n DMA t o f o r m H R u C l C P P h ^ ) ^ ( e q u a t i o n 1 . 1 ) w e r e f i r s t p r e s e n t e d R u C l 2 ( P P h 3 ) 3 + H 2 ^ H R u C l ( P P h 3 ) 3 + H C 1 ( 1 . 1 ) 6 b i n 1 9 7 3 , b u t i n c l u d e d some k i n e t i c d a t a t h a t c o u l d n o t b e e x p l a i n e d . T h e s p e c i f i c d e t a i l s o f t h i s s y s t e m a r e p r e s e n t e d i n C h a p t e r 5 . A n a t t e m p t t o m o r e f u l l y u n d e r s t a n d t h i s t r a n s f o r m a t i o n o f f e r e d t h e i m p e t u s f o r m o s t o f t h e w o r k p r e s e n t e d i n t h i s t h e s i s . A s a r e s u l t o f t h e s e s t u d i e s , i t h a s b e e n f o u n d n e c e s s a r y t o r e - f o r m u l a t e t h e s o l u t i o n c h e m i s t r y o f R u C l g C P P h ^ a n d [ R u C l 2 ( P P h 3 ) 2 ] 2 i n D M A 6 3 \" 1 1 \/ \\ 7 a , 1 2 ( C h a p t e r 3), t h e n a t u r e o f t h e h y d r i d e s p e c i e s p r e v i o u s l y c h a r a c t -e r i z e d - a s [ H R u C l ( P P h 3 ) 2 ] 2 ( C h a p t e r 4)., a n d t h e i d e n t i t y o f t h e c o m p l e x i d e n t i f i e d 7 0 ' 1 3 a s t h e o r t h o m e t a l l a t e d s p e c i e s . , [ R u C l ( o - C ^ P P h p ( P P h ^ ] 2 ( C h a p t e r 6 ) . . T h e r e s u l t s a l s o i n d i c a t e t h a t t h e c o o r d i n a t i n g a b i l i t y o f DMA i s w e a k e r f o r t h e s e c o m p l e x e s t h a n w a s p r e v i o u s l y c o n s i d e r e d , s o t h a t . , , a t l e a s t u n d e r n o n c a t a l y t i c c o n d i t i o n s , . , t h e b i s ( p h o s p h i n e ) s p e c i e s e x i s t p r i m a r i l y a s c h l o r o b r i d g e d d i m e r s . T h e v a r i o u s a s p e c t s o f o r g a n o m e t a l l i c c h e m i s t r y w h i c h a r e m o s t r e l e v a n t t o e a c h p a r t i c u l a r p o r t i o n o f t h i s t h e s i s a r e d i s c u s s e d g e n e r a l l y i n t h e i n d i v i d u a l c h a p t e r s . . H o w e v e r , s i n c e t h e o v e r a l l t h e m e i n v o l v e s a d d i t i o n o f H 2 t o r u t h e n i u m c o m p l e x e s , , a b r i e f i n t r o d u c t i o n o f t h i s a s p e c t o f t r a n s i t i o n m e t a l c h e m i s t r y i s i n c l u d e d h e r e . H y d r o g e n a c t i v a t i o n h a s b e e n r e c o g n i z e d t h u s f a r a s o c c u r r i n g p r i m a r i l y i n t w o w a y s , , d e p e n d i n g o n t h e m e t a l c o m p l e x b e i n g u s e d : o x i d a t i v e a d d i t i o n v i a h o m o l y t i c c l e a v a g e o f t h e H - H b o n d , a n d h e t e r o -l y t i c c l e a v a g e o f t h e b o n d i n t o a h y d r i d e a n d a p r o t o n . T h e d i f f e r e n c e -3-b e t w e e n t h e s e i n v o l v e s m a i n l y t h e p o l a r i z a t i o n o f t h e t r a n s i t i o n s t a t e . O x i d a t i v e a d d i t i o n ( h o m o l y t i c s p l i t t i n g ) o f i s a r e a d i l y d e m o n s t r a t e d mode o f a c t i v a t i o n . C o n s i d e r i n g a h y d r i d e l i g a n d a s a f o r m a l l y -1 u n i t ( s e e a l s o b e l o w ) . , , t h i s c o n c e r t e d p r o c e s s i n v o l v e s i n c r e a s i n g t h e f o r m a l o x i d a t i o n s t a t e a n d c o o r d i n a t i o n n u m b e r b y t w o , a n d i s p a r t i c u l a r l y 8 I common f o r a d d i t i o n s t o s q u a r e p l a n a r d c o m p l e x e s ( e s p e c i a l l y R h a n d I r \" ' \" ) , s i n c e t h i s r e s u l t s i n t h e f a v o r e d o c t a h e d r a l d ^ c o n f i g u r a t i o n ( e q u a t i o n 1 .2 ) . . , O x i d a t i v e a d d i t i o n o f i s o f t e n r e v e r s i b l e ' a n d t h e I r I C l ( C O ) ( P P h 3 ) 2 + H 2 ^ - \u00bb \u00bb H 2 I r m C l ( C 0 ) ( P P h 3 ) 2 ( 1 . 2 ) f o r w a r d r e a c t i o n i s u s u a l l y c o n s i d e r e d t o b e f a v o r e d b y l o w i n i t i a l o x i d a t i o n s t a t e 1 1 * , h i g h m e t a l b a s i c i t y , a n d u n s a t u r a t i o n i n t h e c o o r d -i n a t i o n s p h e r e . D i h y d r i d e p r o d u c t s n o r m a l l y h a v e c i s g e o m e t r y f o r t h e t w o h y d r i d e s , a l t h o u g h i n p r i n c i p l e . , a t r a n s c o n c e r t e d a d d i t i o n i s a l l o w e d 1 5 . D i n u c l e a r c o m p l e x e s c a n r e a c t w i t h H 2 v i a a n e t H 2 a d d i t i o n t o t w o m e t a l c e n t e r s i n w h i c h t h e f o r m a l o x i d a t i o n s t a t e a n d g e n e r a l l y t h e c o o r d i n a t i o n n u m b e r o f e a c h m e t a l i s i n c r e a s e d b y o n e ( e q u a t i o n 1 . 3 ) . 2 C o ( O X ) 3 ~ ' o r 0 s o ( C I X ) . \u201e 6 ~ !' w 2 H C o ( C N ) c 3 ~ (1 .3) M e c h a n i s t i c a l l y , i t i s d i f f i c u l t t o p r o v e w h e t h e r a r e a c t i o n s u c h a s 1 .3 i n v o l v e s a d i r e c t t e r m o l e c u l a r s t e p , . H 2 a d d i t i o n t o u n d e t e c t a b l e a m o u n t s o f d i m e r , o r even- t h e p r o c e s s o u t l i n e d i n e q u a t i o n 1 . 4 . M M + H 2 M H 2 2 MH ( 1 . 4 ) - 4 -I t i s o n l y r e c e n t l y t h a t o x i d a t i v e - a d d i t i o n o f t o a d i m e r h a s b e e n s h o w n t o r e s u l t i n a d i m e r i c p r o d u c t , w i t h o n e h y d r o g e n b o u n d t o e a c h m e t a l 1 6 ( e q u a t i o n 1 . 5 ) . T h e f o r m a l l y I r ( l l ) d a t o m s i n t h e p r o d u c t B u t I J j T I r J ^ I R + H ? \u2022 [lrH(uSBu ) ( C 0 ) ( P P h J J ? GG S ^ - P P h \u201e ^ (1.5) e a c h m a i n t a i n a n 1 8 e c o n f i g u r a t i o n b y f o r m a t i o n o f a m e t a l - m e t a l b o n d . T h i s n o v e l p r o d u c t , h o w e v e r . , i s b e l i e v e d t o a r i s e f r o m a d d i t i o n o f t o o n e e n d o f t h e d i m e r , f o l l o w e d b y h y d r i d e m i g r a t i o n f r o m Ir''\"\"'\"\"'\" t o I r\" ' \" ; t h e m i g r a t i o n w a s a t t r i b u t e d t o t h e e x i s t e n c e o f a c o o r d i n a t e I I I I c o v a l e n t b o n d 1 7 b e t w e e n I r a n d I r w h i c h b r i n g s t h e m e t a l s s u f f i c i e n t l y c l o s e f o r t r a n s f e r . I n t h e f o r m a l l y a n a l o g o u s [ R h ( u - C l ) ( P t o l ^ ) s y s t e m 1 8 , t h e i n t e g r i t y o f t h e m i x e d v a l e n c e p r o d u c t i s m a i n t a i n e d ( e q u a t i o n 1 . 6 ) . H o m o l y t i c c l e a v a g e f o r m a l l y b e c o m e s a n o x i d a t i v e P t o l H * I > v C l \/ \/ \/ \/ \/ | # j ^ \\ \\ P t o l [ R h C l ( P t o l ) ] + H - \u2014 ' B h ^ \" ' R h ^ ( 1 . 6 ) ^ H ^ | ^ \" * C 1 ^ * P t o l P t o l ' J a d d i t i o n o n l y w h e n e l e c t r o n s a r e t r a n s f e r r e d f r o m t h e m e t a l t o t h e h y d r o g e n a t o m s . . H o w e v e r . , s u c h c l e a v a g e may b e f o r m u l a t e d i n t h r e e w a y s 3 d e p e n d i n g o n t h e m e t a l s i n v o l v e d ( e q u a t i o n . 1 . 7 ) . T h e p r o d u c t s 2 M n + o r ( M n + ) 2 + H : H 2 M n ( \u2022 H ) 2 M n _ 1 ( H ) ( 1 . 7 ) 2 M n + 1 ( : H ) -5-d i f f e r o n l y i n t h e p o s i t i o n o f t h e e l e c t r o n s o r i g i n a l l y a s s o c i a t e d w i t h t h e H a t o m s . T h e q u e s t i o n o f m e t a l - h y d r o g e n b o n d p o l a r i t y h a s b e e n 1 9 2 0 a d d r e s s e d ' r e c e n t l y b y C r a b t r e e ' . A d d i t i o n o f t o I r ( C 0 D ) ' ( P M e P h 2 ) 2 a n d I r ( C 0 D ) 2 i s c o n s i d e r e d t o b e r e d u c t i v e r a t h e r t h a n o x i d a t i v e i n c h a r a c t e r . T h e t e r m - h e t e r o l y t i c s p l i t t i n g c a n b e u s e d t o d e s c r i b e a n o v e r a l l t r a n s f o r m a t i o n , o r a m e c h a n i s t i c s i t u a t i o n , a n d g r e a t c a r e m u s t b e t a k e n t o d i f f e r e n t i a t e t h e t w o c a s e s . . N e t h e t e r o l y t i c c l e a v a g e o f i s e x e m p l i f i e d b y e q u a t i o n 1 . 8 , a n d i n v o l v e s s u b s t i t u t i o n o f a h y d r i d e f o r a n o t h e r l i g a n d ( c h l o r i d e ) w i t h n o c h a n g e i n t h e f o r m a l R u C l 6 3 \" + H 2 H R u C l 3 ~ + H + + C I \" ( 1 . 8 ) o x i d a t i o n s t a t e o f t h e m e t a l . . T h e r e l e a s e d p r o t o n i s o f t e n s t a b i l i z e d b y b a s e ; t h i s may b e a n i n i t i a l l y c o o r d i n a t e d l i g a n d , t h e s o l v e n t , o r a n e x t e r n a l l y a d d e d b a s e s u c h a s N E t ^ . . T h e r e a r e t w o p l a u s i b l e m e c h a n i s m s f o r e x p l a i n i n g n e t h e t e r o l y t i c c l e a v a g e . T h e f i r s t i n v o l v e s r e a c t i o n v i a i n i t i a l o x i d a t i v e a d d i t i o n o f t o f o r m a d i h y d r i d e f o l l o w e d b y r e d u c t i v e e l i m i n a t i o n o f HX o r H + . - . w h i c h -may-be . b a s e - a s f o r e x a m p l e , e q u a t i o n 1 . 9 . T h e s e c o n d i n v o l v e s o v e r l a p b e t w e e n a + , b a s e R h L 2 S 2 + H 2 ' - \" R h H 2 L 2 S 2 - R h H L 2 S 2 + H ( 1 ' 9 ) L = t e r t i a r y p h o s p h i n e ; S = s o l v e n t f i l l e d m e t a l o r b i t a l w i t h a n e m p t y h y d r o g e n a n t i b o n d i n g o r b i t a l , a n d r e s u l t s i n a p o l a r i z e d H 2 - m e t a l i n t e r m e d i a t e ( e q u a t i o n 1 . 1 0 ) . T h i s c a n l o s e t h e p o s i t i v e l y p o l a r i z e d e n d o f t h e H m o l e c u l e t o a n i n t e r n a l o r -6-M H 6 + b a s e * - M - H + \u2022 b a s e H + X M - X + H, 2 (1.10) M X ' 6 * M - H + HX e x t e r n a l b a s e . . I n a m e c h a n i s t i c s e n s e , t h e h e t e r o l y t i c p r o c e s s i n v o l v e s a c o n c e r t e d i o n i c s p l i t t i n g o f h y d r o g e n a n d c o o r d i n a t i o n o f h y d r i d e . T h e t w o t y p e s o f m e c h a n i s m s f o r n e t h e t e r o l y t i c c l e a v a g e a p p e a r t o i n v o l v e v e r y d i f f e r e n t t r a n s i t i o n s t a t e s w i t h t h a t o f o x i d a t i v e a d d i t i o n b e i n g f a i r l y s y m m e t r i c c o m p a r e d w i t h a h i g h l y p o l a r i z e d t r a n s i t i o n s t a t e o f g e n u i n e h e t e r o l y t i c s p l i t t i n g . I t i s n o r m a l l y n o t p o s s i b l e t o d i s t i n g u i s h k i n e t i c a l l y t h e n e t h e t e r o l y t i c c l e a v a g e v i a a d d i t i o n - e l i m i n a t i o n f r o m t h e \" g e n u i n e \" h e t e r o l y t i c c l e a v a g e r e a c t i o n , a n d a r g u m e n t s f o r e i t h e r a r e u s u a l l y made o n t h e b a s i s o f t h e o x i d a t i o n s t a t e o f t h e p r e c u r s o r c o m p l e x . . B r o t h e r s h a s r e c e n t l y r e v i e w e d t h i s q u e s t i o n o f h e t e r o l y t i c a c t i v a t i o n o f h y d r o g e n 2 1 . R u t h e n i u m ( l l ) s y s t e m s a p p e a r t o l i e c l o s e t o t h e c e n t e r o f t h e r a n g e o f m e c h a n i s t i c v a r i a t i o n b e t w e e n h y d r o g e n a c t i v a t i o n b y h e t e r o l y s i s a n d a c t i v a t i o n b y d i h y d r i d e f o r m a t i o n 2 1 , s o t h a t t h e mode o f r e a c t i v i t y i s m o r e a m b i g u o u s t h a n f o r o t h e r s y s t e m s . E x a m p l e s o f t h e d ^ t o d ^ t r a n s f o r m a t i o n w i t h d i h y d r i d e f o r m a t i o n a r e r a r e , b u t n o t u n k n o w n ( C h a p t e r 5 ) , a n d i t i s g e n e r a l l y c o n s i d e r e d t h a t r e a c t i o n w i t h r u t h e n i u m ( I I ) t o g i v e a m o n o h y d r i d e m o s t l i k e l y o c c u r s b y i n i t i a l f o r m a t i o n o f a r u t h e n i u m ( l V ) d i h y d r i d e ; f o r e x a m p l e , , e q u a t i o n 1 . 1 1 . H o w e v e r , some w o r k e r s i n t h e f i e l d c o n s i d e r t h a t t h e +4- o x i d a t i o n s t a t e - 7 -Ru1TX + H 2 \u2022 R u I V H - 2 ' X RuT1R + HX ( 1 . 1 1 ) f o r r u t h e n i u m t o b e a n o m a l o u s , a n d h a v e s u g g e s t e d t h a t o n e h y d r o g e n m o l e c u l e i n R u ( l V ) p o l y h y d r i d e c o m p l e x e s s u c h a s R u H , ( P P h _ ) _ , a n d 4 i i R u H 3 ( d p e ) ' 2 , r e m a i n s e s s e n t i a l l y a s s u c h , w i t h l i t t l e w e a k e n i n g o f 4 2 2 \u00ab I 2 3 t h e H - H b o n d ' . . A n i n t e r e s t i n g r e c e n t d e v e l o p m e n t i n t h e s e i n t e r p r e t a t i o n s i s t h e - a d d i t i o n o f H 2 ( o r T)^ o r HD) t o t h e d c o m p l e x M o \u00b0 ( C 0 ) 3 ( P 1 P r 3 ) 2 . T h e p r o d u c t H 2 M o ( C 0 ) ^ ( P ^ P r ^ ) 2 h a s b e e n c h a r a c t e r i z e d 2 if 2 5 a s c o n t a i n i n g b o u n d h y d r o g e n ' ; t h a t i s , m u c h o f t h e i n t e g r i t y o f t h e H - H b o n d i s r e t a i n e d o n c o o r d i n a t i o n . A c o m m e n t o n o r g a n i z a t i o n o f t h e t h e s i s s e e m s i n o r d e r . C h a p t e r d i v i s i o n s w e r e made, . t o . a l l o w . p a r t i c u l a r r e a c t i o n t y p e s t o b e p r e s e n t e d t o g e t h e r . F o r e x a m p l e , a l t h o u g h t h e r e a c t i o n s b e t w e e n H 2 a n d t h e b i s ( p h o s p h i n e ) p r e c u r s o r s , [ R u C l ^ P P h ^ ) 2 ] ^ ( C h a p t e r 5 ) , [RuCl(DMA) ( P P h 3 ) 2 ( 0 2 C C H 2 - f } - 2 ( C h a p t e r 6),, a n d H R u C l ( n b d ) ( P P h ^ ) 2 ( C h a p t e r 7) w e r e s t u d i e d t o g e t h e r i n a n a t t e m p t t o f i n d a common i n t e r m e d i a t e , [ H R u C l ( P P h ^ ) 2 . ; J 2 > t h e r e s u l t s i n d i c a t e , v e r y d i f f e r e n t c h e m i s t r y w i t h i n e a c h s y s t e m , a n d i n t e r p r e t a t i o n o f t h e d a t a i s f a c i l i t a t e d b y p r e s e n t i n g t h e s t u d i e s s e p a r a t e l y . T h e r e s u l t s o f . t h e r e a c t i o n b e t w e e n [ R u C l 2 ( P P h 3 . ) 2 ] 2 a n d H 2>, when, p r e s e n t e d i n C h a p t e r 5 w i t h t h e c o r r e s -p o n d i n g r e a c t i o n o f t h e t r i s ( p h o s p h i n e ) c o m p l e x , ; R u C l 0 ( P P h 0 ) o f f e r m o r e i n f o r m a t i o n t h a n i f e i t h e r w e r e p r e s e n t e d s e p a r a t e l y . S i m i l a r l y i n C h a p t e r 6, i n t e r p r e t a t i o n o f t h e r e s u l t s o f t h e r e a c t i o n b e t w e e n [ R u C l ( D M A > ( P P h 3 ) 2 ( 0 2 C C H 2 7 ^ a n d H 2 a r e a i d e d s o m e w h a t b y t h e r e s u l t s o b t a i n e d f r o m t h e s y s t e m s i n v o l v i n g t h e t r i s ( p h o s p h i n e ) c o m p l e x e s , R u C l ( 0 2 C R ) ( P P h 3 ) 3 . T h i s a p p r o a c h , h o w e v e r , made i t d i f f i c u l t t o p r e s e n t t h e d a t a - 8 -i n a t o t a l l y l i n e a r f a s h i o n . F o r e x a m p l e , , t o a s s i s t i n t h e i n t e r p r e t a t i o n 3*1 \"1 o f t h e P { H } - n . m . r . r e s u l t s o n t h e [ R u C l ^ P P h ^ ^ J ^ \/ H ^ s y s t e m i n C h a p t e r 5 , i t w a s f i r s t n e c e s s a r y t o i n t r o d u c e t h e c h a r a c t e r i z a t i o n a n d n . m . r . . p r o p e r t i e s o f [ H ^ R u C l C P t o l ^ ) ^ ] ^ i n C h a p t e r 4 . I n d o i n g s o , t h e n a t u r a l t r a n s i t i o n b e t w e e n t h e s o l u t i o n c h e m i s t r y ( C h a p t e r 3 ) a n d r e a c t i v i t y t o w a r d ( C h a p t e r 5) o f R u C l ^ P P h . ^ w a s i n t e r r u p t e d . 31 1 S i n c e t h e P { H } . - n . m . r . r e s u l t s o f t h e o t h e r b i s ( p h o s p h i n e ) s y s t e m s w e r e o f l i t t l e a s s i s t a n c e i n i n t e r p r e t i n g t h e r e s u l t s o f C h a p t e r 5, t h e i r p r e s e n t a t i o n w a s d e f e r r e d ' t o C h a p t e r s 6 a n d 7 . -9-C H A P T E R 2. E X P E R I M E N T A L . 2.1 M a t e r i a l s . 2 . 1 . 1 S o l v e n t s . S p e c t r o q u a l i t y o r r e a g e n t g r a d e s o l v e n t s , w e r e o b t a i n e d f r o m A l d r i c h , E a s t m a n , , F i s h e r , M a l l i n c k d r o d t , o r MCB C h e m i c a l C o . T h e t e r m \" p e t r o l e u m e t h e r ( 3 0 \u00b0 - 6 0 \u00b0 C ) \" r e f e r s t o t h e l o w b o i l i n g f r a c t i o n o f p e t r o l e u m d i s t i l l a t e , b o i l i n g a t c a . 3 5 \u00b0 - 6 0 \u00b0 C . T o l u e n e , b e n z e n e , T H F , a n d h e x a n e s w e r e d i s t i l l e d f r o m s o d i u m \/ b e n z e n o p h e n o n e \/ 2 , 5 , 8 , 1 1 , 1 4 -p e n t a o x a p e n t a d e c a n e ( A l d r i c h ) u n d e r o n e a t m o s p h e r e n i t r o g e n 2 5 . W h e n s p e c i f i e d a s d r y : ( a ) a c e t o n e w a s s t i r r e d o v e r a n h y d r o u s K ^ C O ^ f o r 24. h a n d d i s t i l l e d f r o m f r e s h a n h y d r o u s K ^ C O ^ , a n d ( b ) a l c o h o l s w e r e d i s t i l l e d f r o m t h e c o r r e s p o n d i n g m a g n e s i u m a l k o x i d e . . DMA w a s s t i r r e d o v e r C a H ^ f o r a t l e a s t 24 h a n d v a c u u m d i s t i l l e d ; e v e n p u r e r DMA was o b t a i n e d b y f u r t h e r s t i r r i n g w i t h H R u C l t P P h ^ ) ^ ( - 5 0 0 m g \/ L ) f o r 24. h u n d e r a r g o n , a n d v a c u u m d i s t i l l i n g ( s e e S e c t i o n 5 . 3 . 2 ) . A l l d i s t i l l e d s o l v e n t s w e r e s t o r e d i n f l a s k s u n d e r a r g o n i n t h e d a r k . O t h e r s o l v e n t s w e r e u s e d w i t h o u t p u r i f i c a t i o n . 2 .1 .2 G a s e s . P r e - p u r i f i e d h y d r o g e n w a s o b t a i n e d f r o m U n i o n C a r b i d e C a n a d a -10-L t d . ( L i n d e D i v i s i o n ) a n d M a t h e s o n G a s C o . , a n d w a s p a s s e d t h r o u g h a n E n g e l h a r d D e o x o c a t a l y t i c p u r i f i e r t o r e m o v e t r a c e s o f o x y g e n . P u r i f i e d a r g o n , n i t r o g e n , o x y g e n , , c a r b o n m o n o x i d e , a n d c a r b o n d i o x i d e w e r e o b t a i n e d f r o m U n i o n C a r b i d e C a n a d a L t d . , M a t h e s o n G a s C o . , o r C a n a d a L i q u i d A i r L t d . , a n d w e r e u s e d w i t h o u t p u r i f i c a t i o n . 2 . 1 . 3 O t h e r m a t e r i a l s . T r i p h e n y l p h o s p h i n e ( A l d r i c h ) , , t r i ( p j - t o l y l ) p h o s p h i n e , d i p h e n y l -p h o s p h i n o m e t h a n e ( d p m ) , d i p h e n y l p h o s p h i n o e t h a n e ( d p e ) , 1 , 3 - d i p h e n y l -p h o s p h i n o p r o p a n e ( d p p ) , a n d t r i m e t h y l p h o s p h i n e ( S t r e m ) w e r e u s e d a s s u p p l i e d , f o r s y n t h e s e s . . . F o r k i n e t i c m e a s u r e m e n t s , P P h ^ a n d P t o l ^ w e r e r e e r y s t a l l i z e d ' f r o m e t h a n o l a n d e t h a n o l - : d i e t h y l e t h e r , r e s p e c t i v e l y . A c t i v a t e d a l u m i n a w a s s u p p l i e d b y M C B . ( A x 6 1 2 . C h r o m a t o g r a p h i c G r a d e , 8 0 - 2 0 0 ' M e s h ) . . P r o t o n S p o n g e , 1 . , 8 - b i s ( d i m e t h y l a m i n o ) n a p h t h a l e n e , w a s s u p p l i e d by- A l d r i c h , a n d p u r i f i e d b y c o l u m n c h r o m a t o g r a p h y ( d r y p a c k e d a l u m i n a , p e t r o l e u m e t h e r ( 3 0 \u00b0 ^ 6 0 \u00b0 C ) e l u e n t ) t o g i v e a w h i t e s o l i d , m p . 4 7 \u00b0 - 5 0 O C ( l i t . 2 8 47\u00b0-48 0 G ) . . L i t h i u m c h l o r i d e a n d b r o m i d e ( F i s h e r S c i e n t i f i c C o . ) , . A s P h ^ C l ^ H ^ O ( K a n d K L a b o r a t o r i e s ) a n d A s P h ^ C l . H g O ( I C N P h a r m a c e u t i c a l s , I n c . ) w e r e u s e d a s s u p p l i e d . . P P N C 1 ( y - n i t r i d o -b i s ( t r i p h e n y l p h o s p h o r u s ) . c h l o r l d e ) . wa-s k i n d l y s u p p l i e d , b y -the l a b o r a t o r y P r o f e s s o r P . L e g z d i n s o f t h i s d e p a r t m e n t . N o r b o r n a d i e n e ( E a s t m a n ) w a s p u r i f i e d b y p a s s i n g t h r o u g h a c o l u m n o f a c t i v a t e d a l u m i n a p r i o r t o u s e . 2 . 1.4 R u t h e n i u m c o m p o u n d s . The- r u t h e n i u m w a s o b t a i n e d a s R u C l ^ . ' 3 H p O , w h i c h i s a c t u a l l y a -11-m i x t u r e o f R u ( l l l ) a n d R u ( l V ) s p e c i e s 2 9 , a n d w a s . s u p p l i e d o n l o a n f r o m J o h n s o n M a t t h e y L t d . A l l r e a c t i o n s w e r e c a r r i e d o u t u n d e r a n a t m o s p h e r e o f a r g o n o r n i t r o g e n e m p l o y i n g S c h l e n k t e c h n i q u e s . E l e m e n t a l a n a l y s e s w e r e p e r f o r m e d by- M r . P.. B o r d a o f t h i s d e p a r t m e n t . 2 . I.4 . I , D i c h l o r o t r i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( l l ) , R u C l ^ P P h ^ ) ' 3 1 R u C l ^ O H g O ( 2 g , . 7 . 6 m m o l ) w a s r e f l u x e d i n m e t h a n o l ( 5 0 0 mL) f o r 1 5 m i n . A f t e r c o o l i n g t h e s o l u t i o n , P P h ^ ( I 2 . . 0 g , 4-5.8 mmol ) w a s a d d e d a n d t h e s o l u t i o n w a s a g a i n r e f l u x e d f o r 3 h w i t h r a p i d s t i r r i n g . T h e c o m p l e x p r e c i p i t a t e d : , f r o m t h e h o t s o l u t i o n ; a f t e r c o o l i n g t h e m i x t u r e , t h e c o m p l e x w a s f i l t e r e d , w a s h e d w i t h m e t h a n o l , a n d v a c u u m d r i e d . Y i e l d : 7 . 2 g (99%); C-_ , H . _ C l _ P _ R u r e q u i r e s C : 6 7 . 6 4 , H : 4 - 7 3 , 54 45 2 3 0 1 : 7 . 3 9 $ ; f o u n d C : 67..90, H : . 4 . 6 2 , C I : 7 . 1 5 $ . 2 . 1 . 4 . 2 D i c h l o r o t r i s ( . t r i - r p ^ t o l y l p h o s p h i n e ^ r u t h e n i u m ( I I ) , . R u C l 0 ( P t o l 0 ) A 2 ' 3 3 2 5 $ T h e s y n t h e s i s w a s e s s e n t i a l l y t h e same a s t h a t d e s c r i b e d f o r t h e t r i p h e n y l p h o s p h i n e d e r i v a t i v e . , b u t u s i n g i n s t e a d P t o l ^ ( 1 1 . 0 g , 3 6 . 1 m m o l ) a n d r e f l u x i n g f o r . 11 h . . Y i e l d : 7 . . 0 g ( 8 5 $ ) . I n c o n t r a s t t o a p r e v i o u s r e p o r t 3 2 , , t h e i s o l a t e d p r o d u c t w a s ' n o t R u C l _ ( P t o l Q ) , b u t 2 3 4 R u C l ^ P t o l ^ . . T h e s t e p d e s c r i b e d b y K n o t h 3 2 t o r e m o v e t h e e x t r a p h o s p h i n e w i t h H C 1 w a s n o t n e c e s s a r y ; C ^ H ^ C l ^ P ^ R u . r e q u i r e s C : 6 9 . 7 4 , H : 5 . 8 5 $ ; f o u n d C : . 6 9 . 1 2 , H : 5 . 9 6 $ . S e e a l s o T a b l e V I - 4 . f o r 3 1 P -n . m . r . p a r a m e t e r s . 2 . 1 . 4 . 3 D i b r o m o t r i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( I I ) . , R u B r \u201e ( P P h . ) . 3 T h e s y n t h e s i s f o l l o w e d c l o s e l y t h a t f o r R u C l \u201e ( P P h J _ ( 2 . 1 . 4 . 1 ) - 1 2 -e x c e p t t h a t t h e R u C l y ^ B ^ O w a s r e f l u x e d w i t h L i B r ( 2 g , 30 e q u i v a l e n t s ) f o r 4 5 m i n p r i o r t o a d d i n g t h e p h o s p h i n e . . Y i e l d : 7 . 0 g ( 8 8 $ ) ; C 5 ^ H B r g P . R u r e q u i r e s C : 61..90., H : . 4 . 3 3 , B r : 1 5 . 2 5 $ ; f o u n d C : 6 2 . 2 0 , H : 4 . 4 5 , B r : 15 .14$. 2 . 1 . 4 . 4 T r i c h l o r o b i s ( t r i p h e n . y l p h o . s p h i n e ) 4 , d l m e t h y I a c e t a m i d e ) r r u t h e n i u m ( l l i ) ' DMA s o l v a t e , R u C l ^ ( P P h ^ ) 2 ( D M A ) \u2022 ( D M A ) 7 . R u G 1 ^ 3 H 2 0 ( 2 g , 7 . 6 m m o l ) w a s d i s s o l v e d i n DMA ( 4 0 mL) a n d s t i r r e d ' f o r 24'.h a t r o o m t e m p e r a t u r e . - . w i t h P P h ^ ( 4 . 0 g , 1 5 . 3 m m o l ) . T h e g r e e n p r o d u c t w a s f i l t e r e d , , w a s h e d w i t h DMA a n d h e x a n e a n d v a c u u m d r i e d . . Y i e l d : 3- .8g. ( 5 4 $ ) : ; C , . . ,H . , o N o 0 o C l \u201e P o R u ^ r e q . u i . r e s . : C Y :6.Q H : 6 . 1 1 , 44 4\u00b0 2 2 3 2 N : 2 . 8 3 , - C I : 1 0 . 7 3 $ ; f o u n d . C : 6 0 . 7 4 , H : 6 . 0 0 , N : 2 . 8 6 , C I : 1 0 . 8 9 $ ; V-,,., ,. . , at 1 6 3 0 cm ; ; v - p . , , . - ... \u2022 , . , . , - a t - 1'590 cm D M A , u n c o o r d i n a t e d D M A , c o o r d i n a t e d \" T h e - u n c o o r d i n a t e d DMA- c o u l d b e r e m o v e d b y s t i r r i n g t h e s o l i d i n m e t h a n o l o r T H F t o g i v e a n o r a n g e c o m p o u n d - ; C ^ H ^ N O G l ^ P g R u r e q u i r e s C : 5 8 . 6 5 , H : 4 . 8 0 , N : 1 . 7 1 $ ; f o u n d . C : 5 8 . . T 8 , H.: 4 . 8 1 , N : 1 . 7 4 $ ; , . , , a t 1 5 9 0 cm . D M A , c o o r d i n a t e d 2 . 1 . 4 . 5 T r i c h l o r o b i s ( t r i . - p - t o l y l p h o s p h i n e ) ( d i m e t h y l a c e t a m i d e ) -r u t h e n i u m ( l l l ) \u2022 DMA s o l v a t e , R u C l ^ T t o l ^ ) 2 ( D M A ) \u2022 (DMA) 8 . T h e s y n t h e s i s i s b a s e d o n t h a t d e s c r i b e d f o r t h e t r i p h e n y l - ' p h o s p h i n e a n a l o g u e , , b u t w a s d o n e a t h a l f s c a l e : . R u C l y . 3 H 2 0 ( l . O g , 3 . 8 m m o l ) ; P t o l ^ (2..3g, 7 . 5 m m o l ) ; DMA ( 2 0 m L ) . Y i e l d : 2 g ( 7 6 $ ) ; C H ^ ^ C l P ^ u r e q u i r e s C : 6 O . . 6 4 , . H : 6 . 1 1 , . N : 2 . 8 3 , C I : 1 0 . 7 3 $ ; f o u n d C : 6 0 . 7 4 - , H : 6 . 0 0 . , N : 2 . 8 6 , C I : 1 0 . -13-2 . . 1 . 4 . 6 T r i c h l o r o b i s ( t r i p h e n y l a r s i n e ) \u2022 ( m e t h a n o l ) r u t h e n i u m ( I I I ) , R u C l o ( A s P h J \u201e ( M e 0 H ) 3 1 . 3 3 2 R u C l 3 ' 3 H 2 0 ( 0 . . 5 g , 1 . 9 m m o l ) a n d A s P h ^ ( 3 . 7 5 g , - 1 2 . 3 m m o l ) w e r e r e f l u x e d i n m e t h a n o l ( 1 0 0 m L ) 1 i n a i r f o r 3 h . T h e g r e e n s o l i d w a s f i l t e r e d a n d v a c u u m d r i e d . R e c r y s t a l l i z a t i o n f r o m C H ^ C l ^ - m e t h a n o l g a v e e m e r a l d n e e d l e s . . Y i e l d : 1 . 1 g ( 6 8 $ ) ; C H 0 C 1 A s 0 R u r e q u i r e s 3 1 34 i 2 C : 5 2 . 1 6 , H : 4 . 0 2 $ ; . f o u n d C : 5 1 . 2 2 , H : 4 .42$ . . T h e c o o r d i n a t e d m e t h a n o l c o u l d b e r e p l a c e d , b y DMA b y s t i r r i n g t h e s o l i d i n t h e l a t t e r s o l v e n t ; C . n H . o N 0 G l Q A s . o R u r e q u i r e s C : 52-97,. H : 4.33,. N : 1 . 5 4 $ ; f o u n d C : 5 3 . 0 5 , 4U 39 3 2 H : 4 .23, N : 1 .62$. 2 . 1 . 4 . . 7 T r i b r o m o b i s ( t r i p h e n y l p h o s p h i n e ) ( m e t h a n o l ) r u t h e n i u m ( l l l ) , RuBr 3(PPh 3) 2(MeOH) 3 1. R u C l 3 ' , < 3 H 2 0 ( i g , , 3 . 8 m m o l ) w a s r e f l u x e d w i t h L i B r ( 6 g , 69 .1 m m o l ) a n d H B r ( c o n e , a q u e o u s . , 5 mL) f o r 4 h . . i n m e t h a n o l ( 2 0 0 m L ) . T h e m i x t u r e w a s d i l u t e d w i t h - m e t h a n o l ( t o 5 0 0 mL) a n d s h a k e n w i t h P P h 3 ( 2 g , 7 .6 m m o l ) f o r 5 d . T h e r e d - b r o w n s o l i d w a s f i l t e r e d , w a s h e d w i t h m e t h a n o l a n d v a c u u m d r i e d . Y i e l d : 0 . 7 g ( 2 0 $ ) ; C . J O B r P Ru r e q u i r e s j I 3 4 3 2 C : 4 - 9 . 5 2 , . H : 3 . 8 2 $ ; f o u n d C : 5O....4I,. H : 3 . 9 8 $ . . T h e c o m p o u n d i s c o n s i d e r e d f u r t h e r i n S e c t i o n 4 . 2 . 1 . 2.1..4.. 8 T r i b r o m o b i s ( t r i p h e n y l a r s i n e ) . ( m e t h a n o l ) r u t h e n i u m ( i l l ) , R u B r 3 ( A s P h 3 ) 2 ( M e O H ) 3 1 . R u C l y J B ^ O ( 0 , . 5 g , . 1 . 9 m m o l ) w a s s t i r r e d w i t h L i B r ( 3 . 0 g , 34- m m o l ) i n m e t h a n o l ( 1 0 0 mL) f o r 2 4 h . T h e m i x t u r e w a s r e f l u x e d i n a i r w i t h t r i p h e n y l a r s i n e ( 2 . . 5 0 g , 8 . 2 m m o l ) f o r 1 h . . T h e r e s u l t i n g b r o w n s o l i d w a s f i l t e r e d , w a s h e d , w i t h m e t h a n o l a n d v a c u u m d r i e d . Y i e l d : 1 . 4 2 g {16%); C o r , H 0 . 0 B r o A s o R u r e q u i r e s C : 4-5 .10, H : 3 . 4 8 $ ; f o u n d C : 4 6 . 1 0 , 3 \/ 3 4 3 2 - 1 4 -Hr 3 .48%. 2 . 1 . 4 - 9 D i c h l o r o Q b e n z o a t o ) b i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( I I I ) , R u C l 2 ( 0 2 C C 6 H 5 ) ( P P h 3 ) 2 3 1 * . T h e c o m p l e x . , a n d t h e c o r r e s p o n d i n g b r o m o a n a l o g u e , w e r e p r e p a r e d a c c o r d i n g ' t o t h e m e t h o d o f M o o r e a n d R o b i n s o n 3 4 . D i c h l o r o t r i s ( t r i p h e n y l -p h o s p h i n e ) r u t h e n i u m ( l i ) ( 0 . 4 8 g . , 0 . 5 m m o l ) a n d b e n z o i c a c i d ( 0 . 1 2 g , 1 . 0 m m o l ) w e r e w a r m e d t o g e t h e r i n . b e n z e n e ( 1 5 mL) i n a i r , a t c a . 7 0 \u00b0 C f o r 1 5 m i n . T h e r e s u l t i n g r e d r b r o w n s o l u t i o n w a s f i l t e r e d , c o o l e d t o r o o m t e m p e r a t u r e , a n d s e t a s i d e t o a l l o w c r y s t a l l i z a t i o n o f a s o l i d . A f t e r 24 h , t h e r e s u l t i n g r e d ^ - b r o w n p l a t e l e t s w e r e f i l t e r e d , w a s h e d w i t h p e t r o l e u m e t h e r ( 3 0 - 6 0 C.) . , . a n d v a c u u m d r i e d . Y i e l d : 0 . 3 7 g ( 9 0 $ ) ; C ^ H ^ O ^ C l ^ R u . r e q u i r e s C : 6 3 . 1 6 , H : 4 . 3 1 $ ; f o u n d C : 6 3 . 8 9 , H : 4 - .44$ . - T h e c o r r e s p o n d i n g b r o m o a n a l o g u e w a s o b t a i n e d s i m i l a r l y f r o m R u B r 2 ( P P h 3 ) 3 a s d a r k b r o w n c r y s t a l s . . Y i e l d : 0 . 2 7 g ( 6 0 $ ) ; C H 3 5 0 2 B r 2 P 2 R u r e q u i r e s C : 5 6 . 9 7 , . H : 3 - 8 9 $ ; f o u n d C : 5 9 . 7 3 , H : 4 . 1 8 $ . F u r t h e r c h a r a c t e r i z a t i o n o f t h e s e c o m p o u n d s a r e g i v e n i n T a b l e s I V - 1 a n d V I - 2 . 2 . 1 . 4 . 1 0 . T h e d l c h l o r o b i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( l l ) d i m e r , [ R u C . l 2 ( P P h 3 ) 2 ] 2 7 ' 3 5 . T h i s c o m p o u n d w a s p r e p a r e d f r o m R u C l 2 ( P P h 3 ) 3 ( 2 . 1 . 4 . 1 ) b y m e t h o d A , o r f r o m R u C l 3 ( P P h 3 ) 2 ( D M A ) \u2022 ( D M A ) . ( 2 . . 1 .4.4) b y m e t h o d B . M e t h o d A : R u C l 2 ( . P P h 3 ) ^ ( 3 . 0 g , 3 -1 m m o l ) w a s r e f l u x e d i n d r y a c e t o n e ( 5 0 0 ' m L ) f o r 90 ' m i n . , f i l t e r e d , , a n d v a c u u m d r i e d t o g i v e a r u s t r e d s o l i d . . i d e n t i f i e d a s R u 2 C l ^ ( a c e t o n e ) ( P P h 3 ) ^ \u00bb ( a c e t o n e ) . Y i e l d : 2 . 2 g (94$); ( C ? q H C i A 0 C l 9 P 9 R u ) 9 r e q u i r e s C : 62 . 0 7 , . H : 4 . 8 1 $ ; f o u n d C : 6 2 . 0 7 , -15-H : 4.7658. v K B r , , , a t 1 7 0 5 c m - 1 ; v K B r , , . . . a c e t o n e , u n c o o r d i n a t e d a c e t o n e , c o o r d i n a t e d a t 1645 cm .. T h i s s o l i d (2 . .2g , 2.9 m m o l ) w a s t h e n s t i r r e d w i t h a s o l u t i o n o f A s P h , C l . - 2 H o 0 O . l g , 2.4 m m o l ) i n . DMA (25 mL) f o r 3 d , d u r i n g w h i c h t i m e t h e d i m e r d i s s o l v e d . . T h e m i x t u r e w a s f i l t e r e d t o r e m o v e r e s i d u a l u n r e a c t e d s t a r t i n g m a t e r i a l a n d t h e v o l u m e o f t h e f i l t r a t e w a s r e d u c e d - t o - 5 mL u n d e r v a c u u m . . . A d d i t i o n o f m e t h a n o l (100 mL) y i e l d e d a r u s t y b r o w n s o l i d . : . . . I i e r d ! : ,-. 1 . 7 5 g ( 8 1 $ ) . M e t h o d B r R u G l ^ P P h ^ ) 2 ( D M A ) \u2022 (DMA) ( l . 0 g , 1.1 m m o l ) i n DMA (20 mL) w a s s t i r r e d u n d e r (1 a t m ) f o r 24 h . T h e v o l u m e o f t h e r e s u l t i n g b r o w n s o l u t i o n w a s r e d u c e d t o c a . 5 mL., a f t e r w h i c h m e t h a n o l (75 mL) w a s a d d e d . T h e r e s u l t i n g o r a n g e b r o w n s o l i d w a s f i l t e r e d , w a s h e d w i t h m e t h a n o l , a n d v a c u u m d r i e d . . . Y i e l d : 0 . 6 g ( 7 8 $ ) . S o l i d s - o b t a i n e d f r o m e i t h e r m e t h o d s h o w e d a n a l y s e s c o n s i s t e n t w i t h t h i s f o r m u l a t i o n , b u t o c c a s i o n a l l y c o n t a i n e d n i t r o g e n p r e s e n t a s DMA i m p u r i t y ( b y a n a l y s i s ) : . e - . g . (\"G ^ H ^ Q C I ^ P ^ R U ) 2 r e q u i r e s C : 6 2 . 0 7 , H : 4 , 3 4 $ ; f o u n d C : 6 1 . 0 5 , . H : 4 . 5 3 $ ; 3 1 P { 1 H } - n . m . r . ( t o l u e n e - d Q , - 4 0 \u00b0 C ) : P . = 6 0 . 0 p p m , P D = 52.4 p p m , J . \u201e = 42 H z . o A rJ AD T h e c o r r e s p o n d i n g P t o l ^ . d e r i v a t i v e . , [ R u C l ^ P t o l ^ ) 2 ] 2 , w a s p r e p a r e d b y m e t h o d B., b u t a t t w i c e t h e s c a l e : R u C l ^ P t o l ^ ^ D M A ) \u00bb(DMA) ( 2 . 0 g , 2 . 2 0 m m o l ) ; DMA (10 mL)... Y i e l d : 1 . 0 g ( 6 3 $ ) ; ( C ^ H ^ C l ^ R u ) 2 r e q u i r e s C : 6 4 . 6 1 , H : 5 . 4 2 , . N : 0 . . 0 0 $ ; f o u n d C : 6 2 . 8 1 , H : 5 . 4 2 , N : 0 . 8 7 $ , \" ^ P ^ H } - n . m . r . . . ( t o l u e n e - d Q , - 4 0 \u00b0 C ) . s h o w e d o n l y P . = 60 .1 p p m , P = O A D 5 2 . 5 ppm,- J A B = 42 H z . 2 . 1 . 4 . 1 1 R e a c t i o n , b e t w e e n [ R u C l 2 ( P P h , J . 2 ] 2 a n d P r o t o n S p o n g e ( S e c t i o n 5 . 4 . 2 . 1 ) . . [ R u C T 2 ( P P h 3 ) 2 ] 2 ( 7 6 0 m g , 1,1 m m o l ) a n d P r o t o n S p o n g e \u00ae ( 8 6 0 m g , - 1 6 -4 .0 m m o l ) w e r e s t i r r e d a t 7 0 \u00b0 C i n t o l u e n e ( 1 5 mL) f o r 2 h a n d a t r o o m t e m p e r a t u r e f o r a n o t h e r 1 5 h . t o g i v e a r e d s o l u t i o n . . A n o r a n g e -b r o w n s o l i d w a s p r e c i p i t a t e d w i t h d i e t h y l e t h e r ( 5 0 m L ) , f i l t e r e d , w a s h e d w i t h d i e t h y l e t h e r a n d p e t r o l e u m e t h e r ( 3 0 - 6 0 C ) , a n d v a c u u m d r i e d . Y i e l d : - 0 . 4 1 g . T h e n a t u r e o f t h e c o m p o u n d c o u l d n o t b e d e t e r m i n e d b u t t h e f o l l o w i n g d a t a w e r e o b t a i n e d : A n a l y s i s , f o u n d C : 6 2 . 0 3 , H : 4 . 9 7 , . N : 1.24-$; ( t o l u e n e ) : 5 0 3 n m ; 3 1 P { 1 H } - n . m . r . max i n C ^ D ^ a t 3 0 \u00b0 G : s i n g l e t a t .44 - 1 ppm.. T h e i n f r a r e d s p e c t r u m s h o w e d , i n a d d i t i o n t o v i b r a t i o n s o f P P h ^ . , a new a r o m a t i c s k e l e t a l v i b r a t i o n a t 1 6 0 0 cm o f c o m p a r a b l e i n t e n s i t y o f t h o s e t o P P h ^ a t 1 5 8 5 a n d -1 -1 1 1 5 7 0 cm , a n d a m e d i u m i n t e n s i t y p e a k a t 14-00 cm . T h e H - n . m . r . s p e c t r u m ( C ^ D ^ . , 1 0 0 M H z ) s h o w e d o n l y t w o p h e n y l r e s o n a n c e s a t 7 . 8 0 a n d 7 . 0 5 6 , - a n d t w o b r o a d u n d e f i n e d s i g n a l s a t 3.40 a n d 3 . 0 5 6 , o f r e l a t i v e i n t e n s i t i e s 9 . 8 : 1 3 . 7 : 1 : 1 , . T h e s p e c i e s w a s t o t a l l y u n r e a c t i v e t o w a r d 1 a t m H ^ i n b e n z e n e a t 2 5 \u00b0 C o v e r 2 w e e k s , i n t h e a b s e n c e o r p r e s e n c e o f a d d e d P P h ^ \u2022 2 . 1 . . 4 . 1 2 D i - . - u - c h l o r o t e t r a h y d r i d o t e t r a k i s ( . t r i p h e n y l p h o s p h i n e ) d i - r u t h e n i u m ( l l l ) . ' 2DMA s o l v a t e , . . [ H 2 R u C l ( P P h 3 ) 2 ] 2 \u00ab . 2 D M A 7 . R u C l 3 ( P P h 3 ) 2 ( D M A ) \u00bb , ( D M A ) ( 1 g , 1 .1 m m o l ) a n d P r o t o n S p o n g e \u00ae ( i g , 4'.7 m m o l ) w e r e s t i r r e d u n d e r H 2 i n DMA ( 3 0 mL) f o r 24 h , d u r i n g w h i c h t i m e a r e d s o l i d d e p o - s i t e d . T h i s w a s f i l t e r e d , w a s h e d w i t h D M A , h e x a n e s , a n d v a c u u m , d r i e d . Y i e l d : . 4 8 0 m g ( 5 8 $ ) ; C ^ H ^ N O C l P ^ u r e q u i r e s - C : 64.04., H : 5 . 5 1 , N : 1 . 8 7 , C I : . 4 . 7 3 $ ; f o u n d C : 63 . 92 , H : 5 . 5 8 , N : . , . 1 . 7 9 , C I : 4 - 6 1 $ . T h e c o r r e s p o n d i n g t r i p h e n y l a r s i n e d e r i v a t i v e w a s p r e p a r e d a n a l o g o u s l y u s i n g R u C l 3 ( A s P h 3 ) 2 ( M e 0 H ) . . Y i e l d : 5 1 0 m g ( 5 0 $ ) : - 1 7 -C v . n H _ N 0 C l A s o R u r e q u i r e s C : 5 7 . 3 2 , H : 4 -93 , N: 1 . 6 7 , C I : 4.23$; f o u n d C : 5 7 . 1 1 , H : 4 . 9 6 , , N : 1 . 5 0 , C I : 4 . 1 1 $ . T h e p r o c e d u r e f o r s y n t h e s i s i n g t h e c o r r e s p o n d i n g b r o m o a n a l o g u e s , [ H 2 R u B r ( ' P P h 3 ) 2 ] 2 a n d [ H 2 R u B r ( A s P h 3 ) 2 ] 2 w a s t h e s a m e , e x c e p t t h a t R u B r 3 ( P P h 3 ) 2 ( M e O H ) ( 0 . 7 7 g , 0 . 8 8 m m o l ) a n d R u B r 3 ( A s P h 3 ) 2 ( M e 0 H ) ( l . O g , 1 . 0 m m o l ) w e r e u s e d , - r e p e c t i v e l y . . H o w e v e r , t h e s o l u t i o n s d i d n o t d e p o s i t s o l i d s . T h e s o l u t i o n v o l u m e s ( 3 0 mL) w e r e t h u s r e d u c e d i n v o l u m e ( t o 1 0 mL) a n d m e t h a n o l ( 5 0 mL) w a s a d d e d . T h e r e s u l t i n g v i o l e t s o l i d s w e r e f i l t e r e d , w a s h e d w i t h m e t h a n o l , , a n d v a c u u m d r i e d . T h e i n f r a r e d a n d ^ H - n . m . r . ( C ^ D ^ , 3 0 \u00b0 C ) s p e c t r a s h o w e d t h e p r e s e n c e o f D M A . Y i e l d o f [ H 2 R u B r ( P P h 3 ) 2 ] 2 - 2 D M A : 310mg ( 4 0 $ ) ; ( C ^ H N O B r P g R u ) 2 r e q u i r e s C : 60.^46, H : 5 . 2 0 , N : , . 1 . 7 6 $ ; f o u n d C : 6 2 . 3 8 , H : 5 . 3 1 , N: 1 . 3 5 $ . Y i e l d o f [ H g R u B r U s P h ^ 2 ) 2 > 2 D M A : 505mg ( 5 2 $ ) ; ( C ^ 0 H ^ N O B r A s 2 R u ) 2 r e q u i r e s C : 54-44, H : 4 . 6 8 . , N : 1 . 5 9 $ ; f o u n d C : 5 5 . 5 3 , H : 4 -45, N: 1 . 2 3 $ . 2 . 1 . 4 * 1 3 D i - u ^ c h l o r o t e t r a h y d r i d o t e t r a k i s ( t r i p h e n y l * p h o s p h i n e ) d i - r u t h e n i u m ( l l l ) , , [ H 2 R u C i ( P P h 3 ) ' 2 ] \" 2 7 . T h i s c o m p o u n d h a s b e e n p r e p a r e d p r e v i o u s l y f r o m R u C l 3 ( P P h 3 ) 2 ( D M A ) \u2022 ( D M A ) i n t o l u e n e b y a m e t h o d a n a l o g o u s t o t h a t g i v e n 2 . 1 . 4 . 1 2 7 , b u t i n o u r h a n d s , t h e p o o r s o l u b i l i t y o f t h e p r e c u r s o r i n t o l u e n e l e d t o l o w y i e l d s . T h e c o m p l e x [ R u C l ^ P P h ^ 2 ] 2 ( 8 0 0 m g , 1.1 mmol ) a n d P r o t o n S p o n g e \u00ae ( l . 0 5 g , 4 . 9 m m o l ) w e r e s t i r r e d i n t o l u e n e ( 2 0 m L ) . u n d e r H 2 f o r 24 h . D u r i n g t h i s t i m e , t h e s o l u t i o n b e c a m e r e d a n d d e p o s i t e d P r o t o n S p o n g e h y d r o c h l o r i d e . . D r y e t h a n o l ( 3 0 mL) w a s a d d e d a n d t h e m i x t u r e s t i r r e d f o r 3 0 m i n ; t h i s w a s t h e n f i l t e r e d , , w a s h e d w i t h d r y e t h a n o l , d i e t h y l - 1 8 -e t h e r , a n d h e x a n e s , a n d v a c u u m d r i e d . Y i e l d : 600mg ( 8 2 $ ) ; ( C 3 6 H 3 2 C l P 2 R u ) 2 r e q u i r e s C : 6 5 . 2 1 , H : 4.86, N : 0 . 0 0 $ ; f o u n d C : 6 5 . 5 1 , H : 4 .89, N : 0 . 0 0 $ . 2 . 1 . . 4 . 1 4. D i - u - c h l o r o t e t r a h y d r i d o t e t r a k i s ( t r i - p - t o l y l p h o s p h i n e ) d i - r u t h e n i u m ( l l l ) ,. [ H 2 R u C l ( P t o l 3 ) 2 ] 2 8 . R u C l 3 ( P t o l 3 ) 2 ( D M A ) (DMA) ( 2 . 0 g , 2 . 0 mmol ) a n d P r o t o n S p o n g e \u00ae ( l . 5 g , 7 . 0 m m o l ) w e r e s t i r r e d i n b e n z e n e ( 5 0 mL) u n d e r H 2 f o r 24 h . T h e r e s u l t i n g r e d - b r o w n s u s p e n s i o n w a s f i l t e r e d t h r o u g h C e l i t e t o g i v e a d a r k r e d s o l u t i o n . D r y e t h a n o l (4O mL) w a s a d d e d t o t h e s o l u t i o n a n d c r y s t a l l i z a t i o n w a s a l l o w e d t o o c c u r o v e r s e v e r a l h o u r s . T h e r e d s o l i d w a s f i l t e r e d , w a s h e d w i t h d r y e t h a n o l a n d h e x a n e s , a n d v a c u u m d r i e d . Y i e l d : 890mg ( 6 0 $ ) ; ( C ^ 2 H ^ C l P 2 R u > 2 r e q u i r e s C : 6 7 . 5 1 , H : 5 . 9 4 $ ; f o u n d C : 68 . .4I , H : 6 . 3 0 $ . B o t h [ H 0 R u C l ( P ) . 0 L c o m p l e x e s , P = P P h 0 ( 2 . 1 . 4 - 1 3 ) a n d P t o l _ , *c ft (L 3 3 w e r e f a i r l y a i r - s e n s i t i v e i n t h e s o l i d s t a t e , d a r k e n i n g t o g r e e n - b l a c k s o l i d s i n l e s s t h a n o n e h o u r o n e x p o s u r e t o a i r . On o n e o c c a s i o n , a s a m p l e o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 (= 800mg) o x i d i z e d i n l e s s t h a n a m i n u t e o n e x p o s u r e t o a i r , w i t h g e n e r a t i o n o j ^ c o h s i d e r a b l e h e a t a n d s m o k e . P r e s u m a b l y , t h i s e v e n t w a s i n i t i a t e d b y r a p i d o x i d a t i o n o f v e r y f i n e l y d i v i d e d s a m p l e . 2 .1 . 4 .15 C h l o r o h y d r i d o t r i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( I I ) . t o l u e n e s o l v a t e , H R u C l ( P P h 3 ) 3 . t o l u e n e 2 7 . T h e c o m p l e x w a s p r e p a r e d f r o m R u C l 2 ( P P h 3 ) 3 b y a l i t e r a t u r e m e t h o d 3 6 . Y i e l d 7 . 2 g ( 9 0 $ ) ; C ^ H C1P R u r e q u i r e s C : 7 2 . 0 7 , H : 5 . 3 5 $ ; \\ K B r -1 ? n \u00b0 r f o u n d C : 7 1 . 8 7 , . H : 5 . 3 8 $ ; v R u \\ , a t 2 0 2 0 cm ; , - 1 7 . 7 5 ( R u - H . , q , 26 H z ) . -19-T h e c o r r e s p o n d i n g DMA s o l v a t e 6 , H R u C l C P P h ^ ) ^ . D M A w a s p r e p a r e d b y s t i r r i n g a s u s p e n s i o n o f R u C l ^ P P h , ^ ( 2 . 0 g , 2.1 m m o l ) i n DMA (4O mL) f o r 1 8 h u n d e r a t r o o m t e m p e r a t u r e . T h e r e s u l t i n g v i o l e t p o w d e r w a s f i l t e r e d , w a s h e d w i t h DMA a n d h e x a n e s , . a n d v a c u u m d r i e d . Y i e l d : 1 . 4 g ( 6 6 $ ) ; C g H ^ O C l P ^ R u r e q u i r e s C : 6 8 . 8 7 , H : 5.55, N : 1.38$; f o u n d C : 68.93, H : 5.61, N : 1.39$. 2 . 1 .4. . 16 C h l o r o h y d r i d o t r i s ( t r i - p - t o l y l p h o s p h i n e ) r u t h e n i u m ( I I ) , H R u C l ( P t o l 3 ) 3 . B e n z e n e ( 1 0 mL) w a s a d d e d t o a m i x t u r e o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 (660mg, 1..13 m m o l ) a n d r e c r y s t a l l i z e d P t o l ^ (660mg, 2 . 1 7 m m o l ) a n d t h e m i x t u r e h e a t e d t o - 6 0 \u00b0 C . T h e c o l o r o f t h e s o l u t i o n c h a n g e d f r o m r e d t o v i o l e t w i t h i n 5 m i n , a n d t h e g a s a b o v e t h e s o l u t i o n w a s t h e n r e c h a r g e d w i t h p u r e a r g o n t o r e m o v e e v o l v e d H ^ . T h i s t e m p e r a t u r e w a s m a i n t a i n e d f o r 30 m i n , a f t e r w h i c h t h e a t m o s p h e r e w a s a g a i n r e p l a c e d b y a r g o n a n d t h e m i x t u r e s t i r r e d a t r o o m t e m p e r a t u r e f o r 18 h . T h e v o l u m e w a s r e d u c e d t o - 2 mL t o g i v e a v i o l e t p a s t e ; p e t r o l e u m e t h e r (30 -60 C ) ( 8 0 mL). w a s t h e n a d d e d , a n d t h e r e d s o l u t i o n a l l o w e d t o s t a n d f o r 24- h . . V i o l e t c r y s t a l s fo rmed . , , w h i c h w e r e f i l t e r e d , w a s h e d w i t h p e t r o l e u m e t h e r ( 3 0 - 6 0 C ) , a n d v a c u u m d r i e d . Y i e l d : 300mg ( 1 5 $ ) ; C g . ^ C l P ^ u r e q u i r e s C : . 7 2 . . 0 2 , H : 6 . U $ ; f o u n d C : 7 2 . 3 8 , H : 6 . 1 3 $ ; v!Pr\u201e a t 2 0 2 0 c m \" 1 ; 6 3 \u00b0 n C 7 . .70 ( o r t h o p r o t o n s , m ) , 6 . 8 0 6 6 ( m e t a p r o t o n s , d , 8 H z ) . , 2 . 0 0 ( m e t h y l p r o t o n s ) , - I 6 . 8 4 ( R u - H , q , 2 6 H z ) ; 3 0 \u00b0 C 8NNR-. 7 . 0 5 ( o r t h o p r o t o n s , m ) , 6 . 8 0 ( m e t a p r o t o n s , d , 8 H z ) , 2 . 1 5 UJJO J _ 3 ( m e t h y l p r o t o n s ) , - . 1 7 . 7 8 ( R u - H , q , 26 H z ) . - 2 0 -2.1.4 . 1 7 u ^ S u c c i n a t o - d i c h l o r o b i s ( d l m e t h y l a c e . t a m M p h o s p h i n e ) d i r u t h e n i u m ( l l ) , [ R u C l ( D M A ) ( P P h ^ - ^ O g C C H g f J g . T h e H R u C l C P P h ^ ) ^ ( t o l u e n e ) c o m p l e x (l..0g., 1.0 m m o l ) a n d m a l e l c a c i d (I15mg, 1.0 m m o l ) w e r e h e a t e d a n d s t i r r e d a t 60 \u00b0 C i n DMA (5 mL) u n d e r a r g o n f o r 1 6 h . T h e o r a n g e p r e c i p i t a t e w a s f i l t e r e d , w a s h e d w i t h m e t h a n o l . , a n d v a c u u m d r i e d . Y i e l d : 420mg {53%) 1 ( C J . J 0 , P . R u ) o 42 4-1 3 2 2 r e q u i r e s C : 62.57, H : 5.13, N : 1.74, C I : 4.40$; f o u n d C : 62.24, H : 5.24'., N : 1.75, C I : 4.30$. 2 . 1 . 4 . 1 8 ' C a r b o x y l a t o c h l o r o t r i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( I I ) , R u C l ( 0 2 C R ) ( P P h 3 ) 3 (R - CH. 3 \u201e C ^ . , . \u00a3 - C 6 H ^ F , . o - C ^ O C H ^ ) . T h e s y n t h e s i s w i l l b e e x e m p l i f i e d b y r e f e r r i n g t o t h e b e n z o a t o c o m p l e x . H R u C T ( P P h 3 ) y . ( t o l u e n e ) . ( 1 \u00ab 0 g , 1 . 0 m m o l ) , m a l e i c a c i d ( I 1 5 m g 1 . 0 m m o l ) a n d b e n z o i c a c i d ( l . . 2 g , 9 . 8 m m o l ) w e r e s t i r r e d a t 6 5 \u00b0 C i n DMA ('5 mL) i n a s e a l e d S c h l e n k t u b e u n d e r a r g o n f o r 12 h . T h e v o l u m e o f t h e r e s u l t i n g r e d . s o l u t i o n was- r e d u c e d , t o 2 mL u n d e r v a c u u m . M e t h a n o l ( 1 0 0 mL). w a s a d d e d a n d t h e m i x t u r e s t i r r e d f o r 1 h . T h e r e s u l t i n g o r a n g e - b r o w n s o l i d was. f i l t e r e d . , w a s h e d w i t h m e t h a n o l , a n d v a c u u m d r i e d . . Y i e l d : 6 0 0 m g ( 5 8 $ ) . ; . C ^ H ^ C I O ^ P R u r e q u i r e s C : 7 0 . 1 4 , H : 4 . 8 3 , C I : 3 . 3 9 $ ; f o u n d C : . 7 0 . 2 9 , H: 4 . 8 0 , C I : 3 . 3 0 $ . R e p l a c i n g b e n z o i c a c i d w i t h o t h e r c a r b o x y l i c a c i d s , u n d e r o t h e r w i s e i d e n t i c a l c o n d i t i o n s . , l e d t o ' i s o l a t i o n o f t h e c o r r e s p o n d i n g c a r b o x y l a t o s p e c i e s . Y i e l d f o r R u C l ( 0 2 C C H 3 ) ( P P ^ ) 0 . 5 3 0 g ( 5 4 $ ) ; CwH ; o 0 _ C l P o R u r e q u i r e s C : 68.46, H : 4 . 9 2 , C I : 3.61$; 5o 4 \u00b0 2 3 f o u n d C : 6 8 . 2 2 . , H : . 5- .00, C I : 3 . 5 6 $ . Y i e l d \" - f o r H u C - I ( - 0 2 C ' - \u00a3 - C . g H F ) ( P P h ^ y 0 . 8 4 0 g . . ( 7 9 $ ) ; C 6 1 H 0 2 F C 1 P R u r e q u i r e s C : 6 8 . 8 - 9 , H : 4 - 7 4 , C I : 3 . 3 0 $ ; f o u n d C : 6 8 . 5 0 , H : 4 . 8 1 , C I : 3 . 1 0 $ . - 2 1 -Y i e l d f o r R u C l ( 0 2 C - \u00a3 - C 6 H ^ O C H 3 ) ( P P h 3 ) y 0 . 8 6 0 g ( 8 0 $ ) ; C 6 2 H O ^ l P ^ u r e q u i r e s C : 6 9 . 2 4 , H: 4 . 9 7 , C I : 3 . 3 0 $ ; f o u n d C : 6 8 . 8 6 , H : 4 .88, C I : 3 . 2 1 $ . T h e s e c o m p o u n d s a r e d i s c u s s e d f u r t h e r i n C h a p t e r 6. 2 . 1 . 4 . 1 9 D i c a r b o n y l d i c h l o r o t e t r a k i s ( t r i p h e n y l p h o s p h i n e ) d i r u t h e n i u m ( I I ) d i c a r b o x y l a t e , [ R u C l ( C 0 ) . - ( P P h 3 ) 2 J 2 [ d i c a r b o x y l a t e ] . ( d i c a r b o x y l a t e = s u c c i n a t e , m a l e a t e , f u m a r a t e ) . T h e s e c o m p o u n d s w e r e p r e p a r e d b y t h e m e t h o d o f R o b i n s o n a n d U t t l e y 3 7 . T h e p r e c u r s o r H R u C l ( C O ) ( P P h ^ 3 w a s p r e p a r e d b y a l i t e r a t u r e p r o c e d u r e 3 8 ; C ^ ^ ^ O C l P ^ u r e q u i r e s C : 69.36, H : 4 . 8 7 , C I : 3 . 7 2 $ ; f o u n d C : 6 9 - 2 9 , . H: 4 . 9 6 , C I : 3 . 8 5 $ . , v K B r 2010 . , 1920.,, 1 9 0 0 c m - 1 ( v D u , v \u201e J . max K u - x i u u T h e s o l i d d i c a r b o x y l i c a c i d s , ( m a l e i c v f u m a r i c , , a n d s u c c i n i c a c i d s ; 0 . 1 5 0 g , . 1 . 2 9 m m o l ) w e r e , a d d e d t o b o i l i n g s u s p e n s i o n s o f H R u C l ( C O ) ( P P h 3 ) 3 ( 0 . 3 1 g , 0 . 3 3 m m o l ) i n 2 - m e t h o x y e t h a n o l ( 5 m L ) . T h e m i x t u r e s w e r e h e a t e d u n d e r r e f l u x f o r 2 0 . m i n , d u r i n g w h i c h t h e s o l u t i o n s c l e a r e d t o y e l l o w a n d d e p o s i t e d , y e l l o w s o l i d s . A d d i t i o n o f m e t h a n o l ( 2 0 mL) f a c i l i t a t e d t r a n s f e r s a n d t h e s o l i d s w e r e . f i l t e r e d , , w a s h e d , s u c c e s s i v e l y w i t h m e t h a n o l , w a t e r , m e t h a n o l . , , a n d h e x a n e s ( 2 x 1 0 mL e a c h ) , a n d v a c u u m d r i e d . Y i e l d s : 0 . 2 2 to,0.,.235g ( 9 0 - 9 5 $ ) . T h e c o m p o u n d s a r e c h a r a c t e r i z e d i n C h a p t e r 6 . 2 . 1 . 4 . 2 0 \u2022 B i s ( - c a r b o x y l a t o ) b i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( I I ) , R u ( 0 2 C R - ) - 2 ( - P P - h 3 ) 2 (R = CH 3 . \u201e C ^ , . . \u00a3 - C 6 H F , ^ - C ^ O C H ^ ) . B i s ( a c e t a t e ) b i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( . I l ) was p r e p a r e d b y t h e m e t h o d o f M i t c h e l l a n d c o - w o r k e r s 3 9 . R u C l ^ P P h , ^ ( 2 g , 2 . 1 m m o l ) a n d Na(0Ac ) ,\u00ab,3H 9 0 (2. . .84.g, 21 m m o l ) w e r e r e f l u x e d . i n t - b u t a n o l - 2 2 -( 1 0 0 mL) f o r 1 h . T h e warm s u s p e n s i o n was - a l l o w e d ' . - t o - s e t t l e - a n d t h e s o l v e n t d e c a n t e d . A d d i t i o n o f d i e t h y l e t h e r ( 2 0 0 mL) f a c i l i t a t e d t r a n s f e r , a n d t h e o r a n g e s o l i d w a s f i l t e r e d . T h e s o l i d was s u b s e q u e n t l y w a s h e d w i t h d i s t i l l e d w a t e r , m e t h a n o l , d i e t h y l e t h e r , a n d p e t r o l e u m e t h e r ( 3 0 \u00b0 - 6 0 \u00b0 C ) . , a n d v a c u u m d r i e d . Y i e l d : 1 . 1 g ( 7 0 $ ) ; C ^ H gO P 2 R u r e q u i r e s C : 64.60., H : 4.88$; f o u n d C : 64.4-9, H : 4 . 8 3 $ ; V \u2122 1 5 1 5 , 1 4 5 0 cm 1 ( b i d e n t a t e c a r b o x y l a t e ) . T h e c o r r e s p o n d i n g . c a r b o x y l a t o s p e c i e s , R u ( O g C R ) ^ ( P P h ^ ) ^ (R = p _ - C g H ^ F . a n d j D - C g H ^ O C H ^ ) , w e r e i s o l a t e d i n a d v e r t e n t l y d u r i n g a t t e m p t e d p r e p a r a t i o n s o f t h e c o r r e s p o n d i n g H R u ( 0 2 C R ) ( P P h ^ ) ^ c o m p l e x e s . S o d i u m h y d r o x i d e ( l . . 0 2 g . , 2 5 m m o l ) a n d p _ - f l u o r o b e n z o i c a c i d ( 3 . 5 7 g , 25 m m o l ) w e r e s t i r r e d i n m e t h a n o l ( 1 0 0 mL) o v e r n i g h t t o g e n e r a t e t h e s o d i u m c a r b o x y l a t e s a l t . . T h e c l o u d y s u s p e n s i o n c l e a r e d t o g i v e a c o l o r l e s s s o l u t i o n ,;'on h e a t i n g . R u C l ^ P P h ^ ( l . 0 9 g , . 1 . 1 4 m m o l ) w a s a d d e d a n d t h e s u s p e n s i o n , w a s . r e f l u x e d f o r 45 m i n , d u r i n g w h i c h t i m e t h e b r o w n s u s p e n s i o n f i r s t d i s s o l v e d t o . a n o r a n g e s o l u t i o n t h a t f i n a l l y b e c a m e a n o r a n g e s u s p e n s i o n . . T h e c o o l e d m i x t u r e w a s f i l t e r e d , , w a s h e d w i t h d i s t i l l e d w a t e r , m e t h a n o l . , d i e t h y l e t h e r , a n d p e t r o l e u m e t h e r (30 - 6 0 C ) ( 2 x 2 5 mL e a c h ) . , a n d v a c u u m d r i e d t o g i v e a n o r a n g e s o l i d . Y i e l d : 860mg ( 8 3 $ ) ; C ^ H ^ g F g O ^ P g R u r e q u i r e s C : 6 6 \u201e44 , H : 4.24$; f o u n d C : 6 6 . 4 7 , H : 4 - 4 3 $ ; a t - 1 6 0 0 cm 1 (s.,. a r o m a t i c s k e l e t a l v i b r a t i o n ) a n d u\u2014L\u00bb a t 1 4 9 0 ( m ) , . 1420 ( v s ) ( b i d e n t a t e c a r b o x y l a t e ) . UwU A s i m i l a r s y n t h e t i c p r o c e d u r e w a s d o n e w i t h a n i s i c a c i d e x c e p t t h a t t h e q u a n t i t i e s u s e d w e r e s l i g h t l y d i f f e r e n t : p _ - m e t h o x y b e n z o i c a c i d ( a n i s i c a c i d ; 6 . . 8 5 g , 45 m m o l ) , N a O H ( . 1 . 8 g , 4 5 m m o l ) , m e t h a n o l ( 1 5 0 mL) a n d R u C l 2 ( P P h 3 ) 3 ( l . 1 3 g , 1 . 2 m m o l ) . Y i e l d : 750mg . H o w e v e r , 3 1 P { 1 H } -n . m . r . ( T a b l e V I - 4 ) i n d i c a t e d t h e p r o d u c t t o b e a m i x t u r e o f -23-R u ( 0 2 C C 6 H ^ O C H 3 ) 2 ( P P h 3 ) 2 ( - 3 0 $ ) a n d t h e d e s i r e d R E u t O g C C g H O C H ^ ) ( P P h 3 ) 3 c o m p l e x ( - 7 0 $ ) ( S e c t i o n 2..1 . 4 . 2 1 ) . . T h e b i s ( p h o s p h i n e ) s p e c i e s , C 5 2 H 4 4 \u00b0 6 P 2 R u ' r e q u i r e s C : 6 7 . 3 1 , H : 4 . 7 8 $ ; f o u n d C : 6 5 . 2 7 , H : 4 . 8 9 $ . T h e same g e n e r a l p r e p a r a t i v e p r o c e d u r e w a s c a r r i e d o u t w i t h b e n z o i c a c i d . T h e m i x t u r e o f b e n z o i c a c i d ( 5 . 0 5 g , 4 5 m m o l ) , N a O H ( l . . 8 g , . 4 5 mmol),-, m e t h a n o l ( 1 0 0 mL) a n d R u C l ^ P P h ^ ( l . 1 0 g , 1 . 1 5 m m o l ) 31 1 w a s r e f l u x e d , - h o w e v e r , , f o r 4 h . Y i e l d : . ; 0 . 8 7 5 g . p { H } - n . m . r . s p e c t r a ( T a b l e . V I - 4 ) s h o w e d t h e p r e s e n c e o f R u ( 0 2 C C ^ H ^ ) 2 ( P P h 3 ) 2 a s w e l l a s t h e e x p e c t e d H R u ^ C C ^ ) ( P P h ^ ( s e e S e c t i o n 2 . 1 . 4 . 2 1 ) . 2 . 1 . 4 . 2 1 C a r b o x y l a t o h y d r i d o t r i s ( t r i p h e n y l p h o s p h i n e ) r u t h e n i u m ( l l ) , H R u ( 0 2 C R ) ( P P h 3 ) - 3 (R - C H 3 \u201e . C 6 H 5 \u201e \u00a3 ^ C 6 H ^ F \u201e p - C ^ O C H ^ 3 7 \u00bb 4 0 . T h e H R u ( 0 2 C C H 3 ) ( P P h 3 ) 3 c o m p l e x w a s p r e p a r e d b y a l i t e r a t u r e m e t h o d 1 * 1 ; C ^ H O ^ R u . r e q u i r e s C.:. 7 0 . 9 5 , H : 5 . 2 1 $ ; f o u n d C : 7 0 . 9 4 , . H : 5 . 2 4 $ . T h e c o m p l e x e s . H R u ( 0 2 C R ) ( P P h 3 ) 3 , R = C ^ , , , ^ - C ^ F , ^ - C ^ O C H , w e r e p r e p a r e d b y r e f l u x i n g , t h e s o l i d s i s o l a t e d a s d e s c r i b e d i n S e c t i o n 2 . 1 . 4 - 2 0 w i t h -2g e q u i v a l e n t s o f P P h 3 i n m e t h a n o l . T y p i c a l l y , R u ( 0 2 C - \u00a3 - C 6 H ^ F ) 2 ( P P h 3 ) 2 . ( 7 5 0 m g , 0 . 8 3 m m o l ) a n d P P h 3 ( 5 0 0 m g , 1 .91 m m o l ) w e r e r e f l u x e d i n m e t h a n o l ( 1 0 0 . m L ) f o r 19 h. , d u r i n g w h i c h t i m e t h e s u s p e n s i o n c h a n g e d f r o m o r a n g e t o y e l l o w . T h e m i x t u r e w a s f i l t e r e d , a n d t h e r e s u l t i n g s o l i d was . w a s h e d w i t h m e t h a n o l a n d p e t r o l e u m e t h e r ( 3 0 \u00b0 - 6 0 \u00b0 C ' > . ( 2 . x . 2 5 mL e a c h ) . , a n d - v a c u u m d r i e d . Y i e l d : 0 . 7 2 5 g ( 8 5 $ ) ; C 6 1 H 5 0 \u00b0 2 F P 3 R u r e c l u i r e s C : 7 1 . . 2 7 . . H : 4 . 9 0 $ ; f o u n d C : 7 1 . 3 3 , H : 4 . 8 0 $ . S i m i l a r l y , r e a c t i o n o f t h e c r u d e . p _ ^ m e t h o x y b e n z o a t e d e r i v a t i v e ( 0 . 6 5 g ) g a v e 0 . 7 1 \u00bb g H T t u C O ^ E - C g H ^ O C H ^ J \/ ^ P l ^ ) ; C ^ g H 0 P ^ t u r e q u i r e s G : 7 1 . 6 0 , H : 5 . 1 4 $ ; f o u n d C : 7 1 . 3 2 , H : 4 - 9 6 $ . R e a c t i o n o f t h e c r u d e b e n z o a t e -24-species (0.85g) gave 0.86g HRu(0 2CC 6H 5) ( P P ^ ) ; C^H 0 ^ Ru r e q u i r e s C: 72.54, H: 5.09$; found C: 72..25, H: 5.09$. Further c h a r a c t e r i z a t i o n of these hydrides i s presented i n Chapter 6. 2.1.4..22- D i h y d r i d o t e t r a k i . s ( t r i . T p - t o l y l p h o s p h i n e ) r u t h e n i u m ( I I ) , H 2 R u ( P t o l 3 ) ^ . Excess mobile sodium amalgam1*2 was added t o a THF s o l u t i o n (40 mL) of R u C l 2 ( P t o l 3 ) 3 (2.0g, 1.84 mmol) and P t o l (2.0g, 6.56 mmol). The mixture was s t i r r e d under 1 atm,> H 2 f o r 24 h. The d i v i d e d mercury and s a l t s were allowed to s e t t l e and the s o l u t i o n was f i l t e r e d through C e l i t e under argon.. The red f i l t r a t e wes taken to dryness under vacuum to give a yellow solid., that was r e d i s s o l v e d i n toluene; the s o l u t i o n was.again f i l t e r e d through.sC e l i t e and reduced i n volume under vacuum to ^5 mL. A d d i t i o n of petroleum, ether (30\u00b0-60\u00b0C ) 000 mL) immediately p r e c i p i t a t e d a gray s o l i d , which was removed by f i l t r a t i o n and d i s c a r d e d . The red f i l t r a t e was. stored i n the dark overnight and deposited\u2022orange cubes.. These were f i l t e r e d . , .washed with hexanes, and vacuum-dried.. Y i e l d : 1.0g (4-1$); Cg^Hg^P^Ru re q u i r e s C: 76.4-0, H: 6.56$; found C: 76*67, H: 6.86$.;.. \\^ B r\u201e at 2060, 2020 cm\"1; r v u - n .30\u00b0C \u00b0C 6D 6: -10.20 (dt., 40.0 Hz, 34--4 Hz); ^ P{ H)-'n.m.r. (-60\u00b0C): 48.8 ppm, t ; 37 . 9 , t ; ^Jp p = 14 Hz.;. 3 1 P { p h e n y l protons}-n.m.r. spectra (-60\u00b0G) showed a d d i t i o n a l s p l i t t i n g . d u e to Jp ^, but the AA'KK'XX' pa t t e r n was not analyzed. The s p e c t r a l data are given i n Appendix A. The triphenylpho sphine.. d e r i v a t i v e , H 2Ru(PPh 3) ^ 3 _ I t 5, was prepared by a s i m i l a r method but on.a s m a l l e r . s c a l e using i n s t e a d R u C l 0 ( P P h 0 ) 0 <\u2022 3 3 (0.52g, 0.54' mmol) and PPh. (0.60g, 2.3 mmol). Y i e l d : 0.43g (70$). The analyses and spectroscopy indicated, the presence of some -25-H^RuCPPh^)^ i n the i s o l a t e d s o l i d but, s u r p r i s i n g l y k 6 , the mixture showed no i n o r d i n a t e a i r - s e n s i t i v i t y and was r o u t i n e l y handled i n a i r w i t h no apparent d e l e t e r i o u s e f f e c t s : C^Hg^P^Ru r e q u i r e s C: 75.05, H: 5.42$; found C: 72.09, H: 5.21$.; v^ B r\u201e at 2 U 0 cm\"1(w) and 2080 o cm\"1 (m) (H_Ru(PPh,).; l i t . - * 3 2080 cm\" 1); 6^ 5 n C at -7.10 (br, Ru-H, 2 3 4 C 6D 6 H yRu(PPh 3)^, l i t . \" 6 -7.16) and -10,13 ( d t , 41.6 Hz, 34.6 Hz, Ru-H, H 2Ru(PPh 3)^): 3 1P{ 1H} (C 6D 6, 25\u00b0C): 58.0 ppm ( s , H ^RutPPh^) 49.5 and 4I.3 ppm ( t , J P-P U Hz., H.Ru(PPh_),; l i t .2 3 48.8 and 4.06 2 3 4 2 2 ppm, t , J p p = 14.0 Hz; l i t . 1 \" * 55.1 and 46.8 ppm, t , J p p - 15 Hz). The hydride resonance f o r both H 0RuP, complexes, P = Ptol\u201e, PPh 0, was 2 4 3 3 a multiplet,more resembling a doublet of t r i p l e t s than the reported 1*8-50 quartet 1* 1* (see F i g u r e 2.1) ( c o n s i s t e n t w i t h a c i s s t r u c t u r e The present method described f o r the prep a r a t i o n i s su p e r i o r to others which use NaBH and which, i n our hands, gave product 4 -96 j -10.136 \u2014 1 \u2014 \u2022106 -116 Figure 2.1 H i g h - f i e l d r e gion of the H-n.m.r. spectrum showing the hydride of H g R u t P P h ^ i n CgDg at 25\u00b0C under argon (80 MHz) -26-mixtures c o n t a i n i n g a l s o ^R^CO)(PPh^) ; the problem of occluded w a t e r 2 3 i s a l s o e l i m i n a t e d . A d d i t i o n of H\u201e at ambient c o n d i t i o n s to C^D, or toluene-d\u201e 2 6 6 8 suspensions of the H RuP..\/complexes,. P = PPh.', P t o l , caused t o t a l 2 4 - 6\" 3 30 C 3 2 4 6 conversion h a v e - - s i m i l a r l y f o u n d d i f f i c u l t y i n p r e p a r i n g - R u C l - ( M e O H ) ( P P h ^ ) - - - A s d e s c r i b e d b y W a n g 7 , t h i s s y n t h e s i s 3 1 w a s f i r s t r e p o r t e d b y S t e p h e n s o n a n d W i l k i n s o n a n d i n v o l v e d r e a c t i n g I I I 3 x s t o i c h i o m e t r i c q u a n t i t i e s o f P P h _ w i t h R u B r ( M e O H ) . , , ^ 3 x o - x d e v e l o p e d i n s i t u f r o m m e t h a n o l i c s o l u t i o n s o f R u C l ^ . x H ^ O a n d L i B r : \" R u B r 3 ( M e 0 H ) 3 \" + 2. P P h - *\u2022 R u B r 3 ( M e 0 H ) ( P P h 3 ) _ (.4.15) T h e p r e p a r a t i o n s g i v e n a r e n o n - s p e c i f i c a b o u t r e a c t i o n c o n d i t i o n s , p a r t i c u l a r l y w i t h r e s p e c t t o . t i m e . I n o u r h a n d s , t h e r e a p p e a r e d t o b e l i t t l e q u a l i t a t i v e d i f f e r e n c e i n t h e p r o d u c t , i f t h e r e a c t i o n p r o c e e d ' e d \" a e r o b i c a l l y o r a n a e r o b i c a l l y , o r i n t h e a b s e n c e o r p r e s e n c e o f l i g h t . I n a l l c a s e s , t h e b r o w n s o l i d w h i c h d e p o s i t e d g a v e . e l e m e n t a l a n a l y s e s w h i c h w e r e h i g h i n p e r c e n t c a r b o n , ( f o r e x a m p l e , f o u n d C : 5 9 . 7 7 ; H : 4 . 3 0 $ ; c a l c u l a t e d f o r R u B r ^ M e O H ) ( P P h 3 ) _ : C : 4 - 9 . 5 2 ; H : 3 . 8 2 $ ; c a l c u l a t e d f o r R u B r 2 ( P P h 3 ) : C : 6 1 , 9 0 ; H : 4 - 3 3 $ ) a n d -108-appeared to conta i n s i g n i f i c a n t amounts of diamagnetic m a t e r i a l . In some cases, pure RuBrpJPPb^)^ was recovered i n low y i e l d , although g e n e r a l l y the i s o l a t e d s o l i d s were mixtures of R u ( l l ) and R u ( l l l ) . S o l i d s t a t e e.s.r. spectroscopy was a u s e f u l t o o l f o r s e m i q u a n t i t a t i v e l y measuring the r u t h e n i u m ( i l l ) content i n a given sample. The e.s.r. spectra of the o t h e r . w e l l c h a r a c t e r i z e d r u t h e n i u m ( i l l ) species e x h i b i t e d very strong, c h a r a c t e r i s t i c 1 1 6 ~ 1 1 9 ' three. part'-'signals of comparable i n t e n s i t i e s at -196\u00b0C (Table IV-1). By comparing the r e l a t i v e s i g n a l i n t e n s i t i e s of the .RuBr^OMeOH) (.PPh^\")'samples with that of RuCl 3(PPh 3) 2(DMA)-DMA, a measure of the r u t h e n i u m ( i l l ) content was obtained. I f the r e a c t i o n was c a r r i e d out i n a i r , and monitored by e.s.r., s e l e c t i v e c r y s t a l l i z a t i o n s y i e l d e d small q u a n t i t i e s of a c r y s t a l l i n e m a t e r i a l w i t h a high r u t h e n i u m ( i l l ) content. Elemental analyses confirmed that the r a t i o of ''.'RuBr^MeOH) (ipPh^-) ^ to R u B r ^ P P h ^ was apparently h i g h i n these samples. (Found: C: 54.62$) Optimum y i e l d s (20-30$) and p u r i t i e s (found: C: 50.41, 50.76; H: 3.79, 3.98$) were obtained i f concentrated aqueous HBr was added (ca.-1$ i n MeOH) and the r e a c t i o n mixture shaken f o r extended periods of time. Although s o l i d deposited a f t e r 3-8 hours, the mixture was f i l t e r e d only a f t e r 4-7 days. U n f o r t u n a t e l y the formation of t h i s compound seemed to vary w i t h batches of precursor RuCl^.xHgO so as to make t h i s method's general a p p l i c a b i l i t y r a t h e r suspect. Nevertheless, s u f f i c i e n t m a t e r i a l was obtained to measure hydrogen uptakes and prepare some 31 1 [ H 2 R u B r ( P P h 3 ) 2 ] 2 . The P{ H}-n.m.r. of the i s o l a t e d hydride species, however, showed a d d i t i o n a l peaks assignable to HRuBr(PPh 0)\u201e 6 8, 3 3 i n d i c a t i n g the presence of r e s i d u a l R u B ^ ^ P h ^ ) ^ i n the s t a r t i n g material,{see Appendix C). - 1 0 9 -T A B L E I V - 1 . , - s . r . . p a r a m e t e r s o f m o n o m e r i c r u t h e n i u m ( l l l ) c o m p o u n d s a t - 1 9 6 \u00b0 C . C o m p o u n d *1 \u00a7 2 g 3 R u C l 3 ( P P h 3 ) 2 ( D M A ) . ( D M A ) 2.4O 2 . 3 2 1 . 8 2 R u C l 3 ( P t o l 3 ) 2 ( D M A ) . ( D M A ) 2 . 3 9 2 . 3 3 1 . 8 0 R u C l 3 ( P P h 3 ) 2 ( D M A ) 2 . 4 3 2.4I 1 . 7 8 R u C l 3 ( A s P h 3 ) 2 ( M e O H ) 2 . 5 5 2 . 3 0 1 . 7 0 R u C l 3 ( A s P h 3 ) 2 ( M e O H ) b 2 . 5 2 2 . 2 5 1 . 7 1 R u B r 3 ( P P h 3 ) 2 ( M e O H ) 2 . 7 4 2 . 3 9 1 . 7 4 R u B r 3 ( A s P h 3 ) 2 ( M e O H ) 2 . 6 0 2.4O 1 . 6 3 R u C l 2 ( 0 2 C C H 3 ) ( P P h 3 ) 2 2 . 3 4 2 . 2 3 1 . 8 5 R u C l 2 ( 0 2 C P h ) ( P P h 3 ) 2 2 . 3 5 2 . 2 3 1 . 8 5 R u B r 2 ( 0 2 C P h ) ( P P h 3 ) 2 2 . 3 6 2 . 3 0 1 .91 a - . M e a s u r e d o n t h e V a r i a n E 3 0 E . s.- .r . s p e c t r o m e t e r - S e e a l s o A p p e n d i x B . b g V a l u e s t a k e n f r o m r e f e r e n c e 1 1 9 . - 1 1 0 -A, . 2 . 2 G a s u p t a k e a n d e v o l u t i o n . T h e r e s u l t s o f t h e c o n s t a n t p r e s s u r e g a s u p t a k e a n d e v o l u t i o n e x p e r i m e n t s a r e g i v e n i n T a b l e s I V | 2 a n d I V - 3 . I n t h e p r e s e n c e o f a d d e d P r o t o n S p o n g e , t h e c o m p o u n d s R u X p T L ^ ( X , Y = 0 1 , B r , O ^ C R ; L = P P h y P t o l ^ , A s P h ^ ) r e a c t e d w i t h 2 m o l e s o f h y d r o g e n p e r m o l e o f r u t h e n i u m ( l l l ) (4.I6) . . . W h e n r u t h e n i u m ( l l ) p r e c u r s o r s w e r e u s e d , R u X 3 L 2 + 2 H 2 \u2022 *~ i [ H 2 R u X L 2 ] 2 + 2 H X U . 1 6 ) o n l y 1 g e q u i v a l e n t s o f H_ 2 w e r e a b s o r b e d . (4.17), t h e d i f f e r e n c e c o r r e s p o n d i n g t o t h e r e d u c t i o n o f R u ( l l l ) t o R u ( l l ) b y 5 e q u i v a l e n t o f H 2 (.4.18): \u00bb R u X 2 L 2 ' + l i H 2 \u2022 i [ H 2 R u X L 2 ] 2 + HX (4.17) R u X 3 L 2 + i H 2 \u00bb- ' R u X 2 L 2 ' + H X 1 8 ) A l t h o u g h t h e p r o d u c t i s f o r m a l l y r u t h e n i u m ( I I I ) , t h e r e a c t i o n i s b e l i e v e d ' t o p r o c e e d t h r o u g h r u t h e n i u m ( l l ) i n t e r m e d i a t e s ( S e c t i o n 5 , . 3 . 5 ) . 4 . 2 . 3 P r e p a r a t i o n o f c o m p l e x e s . T h e c o m p l e x e s [ H 2 R u X L 2 ] 2 w e r e p r e p a r e d b y s t i r r i n g t h e c o r r e s p o n d i n g r u t h e n i u m ( i l l ) p r e c u r s o r w i t h P r o t o n S p o n g e i n DMA o r b e n z e n e u n d e r H 2 f o r 2 d a y s , f o l l o w e d b y t h e w o r k u p d e s c r i b e d i n C h a p t e r 2 . T h e b r o m o c o m p l e x e s w e r e d i f f i c u l t t o p r e p a r e a n a l y t i c a l l y -111-T A B L E I V - 2 . H y d r o g e n u p t a k e d a t a f o r r u t h e n i u m b i s ( p h o s p h i n e ) a n d - ( a r s i n e ) a p r e c u r s o r s . C o m p l e x (mg) S o l v e n t P . s J % mg f i m e C , h U p t a k e \/ R u A (27.5) t o l .110 \u2022\" 1.7 1.45 A (35.0) t o l 10.5 d 13 1.45 A (29.2) DMA 100 2.1 1.53 A (27.6) DMA 100 2.8 1.41 A (43.0) t o l 128 2.8 1.45 A (46.1)' t o l 6 132. 2.8 1.45 A (27.6) DMA 0 2.8 0.83 A ('30.7) t o l 0 12 0.00 A (34.8) f DMA 0 2.8 0.81 B (35.5)' DMA 100 3.4 1.94 B (39.7) t o l 113 24 2.01 B (45.7) DMA 0 12' ' 0.78 B' (45.7) DMA 100 4.7 2.03 B' (39.3) DMA 100 .6.1 2.00 B ' (46.0) DMA .. 0 4.8 1 .26 C (26.1) DMA 100 6.9 1 .84 c (31 .8 ) DMA 200 25 1.86 D (33.0) DMA 100 \"' 2.4 0.00 D (33.4) DMA 110 g . 2 \u2022 4- 0.00 D ' (30.7); DMA 0 g 2.2 0.00 D (30.7) t o l 100 g 12 0.00 D (43.5) t o l 115 2.2 0.00 E (32.1). DMA 0 3.4 1 .06 E (31.2) DMA 120 1.9 2.07 E (\"35.0) \u2022 t o l 0 6 0.00 E (30,1) t o l , . 110 \"6 . 0.00 -112-T a b l e I V - 2 ( c o n t i n u e d ) . C o m p l e x . (mg) S o l v e n t P . S . W , mt T i m e . , h U p t a k e \/ R u E\u00bb (30.2) DMA 104 3.9 2.00 E\u00bb (32.1) DMA 0 3.9 0.95 F (32.4) DMA 0 12 1.47 F (31.9) DMA 105 24 1 . 8 7 G (35.8) DMA- 2 1 7 12 1.84 H (35.0) DMA 100 12 2.10 I ( 3 1 . 7 ) t o l 0 19. 1.06 I (35.6) h t o l 0 \u2022 5.c: 1.35 I (35.0) h t o l 100 1 3 1.45 I (34.2) h t o l 124 5 1.47 J (30.1) t o l 0 1.4 2.311 J (28.3) DMA 0 1.4 2.501 a A t t o t a l p r e s s u r e o f 7 6 0 mm H g , 30 + 2 \u00b0C , 1 0 . 0 mL s o l v e n t s o t h a t [ R u ] _ - 5 x 1 0 \" 3 M . b C o m p l e x e s u s e d w e r e : . A = [ R u C l 2 ( P P h 3 ) 2 ] 2 ; B = R u C l ^ P P h ^ ) 2 ( D M A ) \u2022 (DMA) ; . ; . .C = R u C l _ ( 0 2 C C H ) ( P P h - ) 2 ; C -B ' = R u C l 3 ( P . t o l 3 ) 2 ( D M A \" ) -R u C l o ( 0 o C C . H c ) ( P P h o ) o ; b\" = R u ( 0 o C C H j \u201e ( P P h J \u201e ; E = R u C l _ ( A s P h 0 ) ( D M A ) 2 2 O i> 3 2 2 j> 2 jJ 2 3 J E ' = R u C l 3 ( A s P h 3 ) 2 ( M e 0 H ) ; F = R u B r ^ P P h . ^ ) 2 ( M e 0 H ) ; G = R u B r 2 ( 0 2 C C 6 H 5 ) ( P P h 3 ) 2 ; H = R u B r 3 ( A s P h 3 ) 2 ( M e 0 H ) ; I - . . [ R u C l ( D M A ) ( P P h - ) 2 ( 0 2 C C H 2 f _ J - 2 J ' ; J = H R u C l ( n b d ) ( P P h 3 ) ^ . R e p r e s e n t s t h e t i m e t h e e x p e r i m e n t w a s a l l o w e d t o c o n t i n u e . G e n e r a l l y , h o w e v e r , t h e r e a c t i o n m i x t u r e s s h o w e d n o u p t a k e d u r i n g a t l e a s t t h e l a s t s e v e r a l t h o u s a n d s e c o n d s o f t h e t i m e q u o t e d ( s e e , f o r e x a m p l e . F i g u r e s 5 . 1 7 t o 5 . 2 2 ) . P . S . : R u = 1 : 1 . 3 9 0 mm H g . 2 0 \u00b0 C . - 1 1 3 -T a b l e I V - 2 ( c o n t i n u e d ) . g I n t h e p r e s e n c e o f 1 0 0 mg P P h ^ . h 3 5 \u00b0 C i I n c l u d e s s t o i c h i o m e t r y o f t o s a t u r a t e n o r b o r n a d i e n e l i g a n d t o n o r b o r n a n e . j C h a p t e r 6 . k C h a p t e r 7 . - 1 1 4 -T A B L E I V - 3 . G a s e v o l u t i o n d a t a & t o c o n f i r m t h e s t o i c h i o m e t r y [ H 2 R U C 1 P 2 J 2 ( P = P P h 3 , P t o l ) . C o m p l e x 1 3 (mg) R e a g e n t . . (mg) A t m o s p h e r e T i m e 0 E v o l u t i o n \/ R u A d P P h 3 (42) H 2 1400 s 0.40 A 6 P P h 3 ( 5 5 ) H 2 1 6 3 0 s 0 . 5 0 A ( 2 7 . 2 ) P P h 3 ( 4 4 ) H 2 2 3 5 s 0 . 4 5 A (37.4) P P h 3 ( 1 0 0 ) A r 2 2 0 s 0 . 4 5 A ( 3 7 . 7 ) DMAHC1 (60) A r 2 0 0 0 s 1 . 3 7 A ( 1 5 . 6 ) DMAHC1 ( 7 0 ) A r 3 8 0 0 s 1 . 5 0 A ( 3 3 . 0 ) b i p y ( 1 3 3 ) A r 3 h 0.41 A ( 3 3 . 3 ) - A r 18 h 0 . 2 2 A ( 3 5 . 1 ) - A r 18 h 0 . 0 9 B (36.0) P t o l ( 1 0 0 ) A r 3 0 0 s 0 . 4 9 B ( 3 9 . 8 ) b i p y ( 1 3 3 ) A r 12- H : 0 . 4 8 B U0.7)f b i p y ( 1 3 3 ) A r 3 6 0 0 s 0 . 4 8 I n 1 0 . 0 mL. D M A , P = 7 6 0 mm H g , 3 0 \u00b0 C . A = [ H 2 R u C l ( P P h 3 ) 2 J 2 ; B = [ H 2 R u C l ( P t o l 3 ) _ ] T i m e a f t e r w h i c h n o f u r t h e r c h a n g e o c c u r r e d ; h o w e v e r , t i m e s r e c o r d e d s h o u l d n o t b e ' c o n s i d e r e d t h e ' m i n i m u m l i m i t i n g v a l u e s . I n s i t u r e a c t i o n , i n v o l v e d s h a k i n g 2 9 . 4 mg [ R u C l 2 ( P P h 3 ) 2 ] 2 i n \u2022 DMA - w i t h 100 . .mg P . S . u n d e r H 2 f o r - 1 0 0 0 0 s t o g e n e r a t e \u2022 [ H 2 R u C l ( P P h - ) 2 } 2 \u00ab ' E v o l u t i o n \/ R u r e p r e s e n t s t h e . c h a n g e s w h i c h ' o c c u r r e d - ' w h e n s o l i d - . P P h 3 w a s a d d e d t o t h e - s o l u t i o n u n d e r E^. A s i n ( d ) , b u t u s i n g 2 1 . 7 mg R u C l ^ P P h ^ 2 ( D M A ) \u2022 (DMA) a s t h e p r e c u r s o r . I n t o l u e n e . - 1 1 5 -p u r e , p o s s i b l y o w i n g t o i m p u r i t i e s p r e s e n t i n t h e s t a r t i n g m a t e r i a l s ( s e e 4 . 2 . 1 ) , a n d t h u s m o s t e m p h a s i s w a s p l a c e d o n t h e c h l o r o p h o s p h i n e c o m p l e x e s . B o t h p h o s p h i n e a n d a r s i n e h y d r i d o c h l o r o c o m p l e x e s d e p o s i t e d f r o m DMA s o l u t i o n s a s r e d o r v i o l e t s o l i d s , r e s p e c t i v e l y . T h e b r o m o a n a l o g u e s c o u l d b e o b t a i n e d b y p r e c i p i t a t i o n w i t h m e t h a n o l . M i c r o a n a l y s e s a n d i n f r a r e d d a t a s h o w e d t h e p r e s e n c e o f o n e m o l e o f DMA p e r m o l e o f r u t h e n i u m . T h e c a r b o n y l s t r e t c h i n g b a n d i n t h e i n f r a r e d s p e c t r a o f t h e s e c o m p l e x e s a l l a p p e a r e d a t I64O cm ( K B r d i s c ) , c l o s e t o t h a t f o r t h e f r e e s o l v e n t ( 1 6 6 0 c m \" ) . I t i s n o t c l e a r w h e t h e r t h e DMA i s c o o r d i n a t e d o r n o t , s i n c e c o o r d i n a t i o n s h i f t s t h r o u g h o x y g e n r e s u l t s i n d o w n w a r d s h i f t s o f t h i s p e a k o f c a . .50 t o a n \u201e - 1 120-122 oU cm . T h e c o m p l e x e s [ H 2 R u C l P 2 ] 2 ( P = P P h 3 , P t o l 3 ) w e r e p r e p a r e d f r o m c o n c e n t r a t e d b e n z e n e s o l u t i o n s b y a d d i n g e t h a n o l . B e c a u s e o f t h e i r g r e a t e r s o l u b i l i t y , s a m p l e s o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 d e p o s i t e d m o r e s l o w l y t h a n t h e P P h ^ a n a l q g u e s . > a n d w e r e m o r e c r y s t a l l i n e . B o t h c o m p o u n d s h a d a t e n d e n c y t o c o n t a i n t r a p p e d b e n z e n e , r e s u l t i n g i n s l i g h t l y h i g h c a r b o n a n a l y s e s . T h e - [ H 2 R u C l ( P t o l 3 ) 2 3 2 c o m p o u n d w a s s u f f i c i e n t l y s o l u b l e f o r m o l e c u l a r w e i g h t m e a s u r e m e n t s t o b e m a d e . C r y o s c o p i c m e a s u r e m e n t s i n b e n z e n e u n d e r a r g o n g a v e a v a l u e o f 1 3 0 0 , w h i c h i s c o n s i s t e n t w i t h t h e d i m e r f o r m u l a t i o n ( c a l c u l a t e d m o l e c u l a r w e i g h t f o r [ H 2 R u C l ( P t o l 3 ) 2 ] 2 i s U 9 5 ) . D e s p i t e i t s f o r m a l o x i d a t i o n s t a t e o f r u t h e n i u m ( I I I ) , a n d i n c o n t r a s t t o t h e m o n o m e r i c r u t h e n i u m ( I I I ) d e r i v a t i v e s e x a m i n e d , t h e c o m p l e x w a s , e s s e n t i a l l y , e . s . r . s i l e n t . One s o l i d s a m p l e o f [ H 2 R u C l ( P P h 3 ) 2 ] 2 g a v e t h e e . s . r . p a t t e r n s h o w n i n F i g u r e 4.1 . I t w a s o n l y o b s e r v e d a t 2 5 \u00b0 C a n d n o t a t l i q u i d N 9 t e m p e r a t u r e s , a n d - 1 1 6 -\u2022 ( \u2022 \u2022 \u2022 \u2022 \u2022 1 1 1 \u2022 111 \u2022 \u2022 i \u2022 1 1 1 1 \u2022 \u2022 \u2022 \u2022 11 \u2022 \u2022 11 11 \u2022 \u2022 \u2022 \u2022 1 1 1 1 1 1 \u2022 \u2022 \u2022 11 \"\u2022 \u2022 i \u2022 i \u2022 \u2022 111 \u2022 \u2022 \u2022 \u2022 11 HI \u2022 i 1.98 1.88 200 4 4 gauss . . r\u2014 K 2.17 ' \u2022 \u2022 ' \u2022 I l l \u2022 \u2022 \u2014 \u2022 \u2022 \u2022 \u2022 + 2.27 \u2022 i \u2022 F i g u r e 4.1 Observed e.s.r. s i g n a l f o r one sample of [ H 2 R u C l ( P P h 3 ) 2 ] 2 . was l e s s than 1% as in t e n s e as those p r e v i o u s l y observed ( S e c t i o n 4.2.1). However, the e.s.r. s i g n a l was not observed i n other samples prepared by i d e n t i c a l procedures, and was l i k e l y due to an undefined t r a c e i m p u r i t y . The [ H 2 R u C l P 2 ] 2 complexes (P = PPh^, P t o l ^ ) obeyed Beer's Law i n DMA under H 2 over the concentration range 1 . 8 x 1 0 to 1.2 x 10 showing a X at 495 nm with'an e x t i n c t i o n c o e f f i c i e n t of 1500 M cm max \u2014 These compounds, p a r t i c u l a r l y the PPh^ d e r i v a t i v e , were sometimes unstable i n DMA a t these concentrations, showing about a 10$ decrease i n absorbance at 495 nm with time, even when the solvent was r i g o r o u s l y p u r i f i e d (see S e c t i o n 5.3.2). This i n s t a b i l i t y was not appr e c i a b l e a f f e c t e d by the presence or absence of H 2. As a r e s u l t , -1 -1 s l i g h t l y lower values f o r e were o f t e n obtained (=1200-1400 M cm ). - 1 1 7 -T h e s p e c t r u m o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 i n t o l u e n e w a s s h i f t e d s l i g h t l y t o l o w e r e n e r g y ( A _ a x a t 5 0 0 nm) t h a n i n D M A , b u t w a s o t h e r w i s e i d e n t i c a l ( F i g u r e 4.2). A t t e m p t s t o p r e p a r e t h e c a r b o x y l a t o a n a l o g u e s b y c o m p a r a b l e r o u t e s w e r e u n s u c c e s s f u l . R u ( 0 2 C C R \" 3 ) 2 ( P P h 3 ) 2 w a s c o m p l e t e l y i n e r t t o w a r d h y d r o g e n u n d e r a n y m i l d c o n d i t i o n s . T h e p r o d u c t s o f h y d r o g -e n a t i n g R u X 2 ( 0 2 C R ) ( P P h 3 ) 2 ( X = C l , B r ; R = C g H - , C H \" 3 ) 3 - i n - t h e p r e s e n c e o f b a s e s h o w n o c a r b o x y l a t e l i g a n d i n t h e i . r . s p e c t r u m a n d w e r e i d e n t i f i e d a s t h e [ H 2 R u X ( P P h ^ ) 2 ] 2 c o m p l e x b y v i s i b l e s p e c t r o s c o p y . 3 5 0 4OO 5 0 0 6 0 0 7 0 0 8 0 0 W a v e l e n g t h , n m . F i g u r e 4 . 2 V i s i b l e s p e c t r a o f [ H 2 R u C l ( P P h 3 ) 2 J 2 i n ( a ) D M A , a n d ( b ) t o l u e n e . V a l u e s i n p a r e n t h e s e s g i v e A n i c i x - 1 1 8 -4.2.4. N . m . r . s p e c t r o s c o p y . ' 1 4.2.4.I H - N . m . r . T h e [ H 2 R u X L 2 ] 2 c o m p o u n d s (X = C l , B r ; L = P P h ^ , P t o l , A s P h ^ ) 1 e a c h e x h i b i t e d a b r o a d h i g h - f i e l d h y d r i d e r e s o n a n c e i n t h e H - n . m . r . i n C g D g a t 2 5 \u00b0 C ( T a b l e IV-4).. T h e i n t e g r a t e d i n t e n s i t i e s o f t h e s e h y d r i d e s g e n e r a l l y d e c r e a s e d s l o w l y w i t h t i m e , b u t f r e s h l y p r e p a r e d s o l u t i o n s i n d i c a t e d c a , 1 . 5 h y d r i d e s p e r r u t h e n i u m . T h i s w a s b a s e d o n c o m p a r i s o n w i t h t h e DMA r e s o n a n c e s i n [ H 2 R u C l L 2 ( D M A ) ] 2 ( L = P P h -o r A s P h ^ ) o r t h e m e t h y l r e s o n a n c e s i n [ H \" 2 R u C l ( P t o l 3 ) ^ e 31 b r o a d n e s s w a s n o t a f f e c t e d b y P d e c o u p l i n g o r t h e p r e s e n c e o f H 2 ( g ) , a n d w a s q u a l i t a t i v e l y i n d e p e n d e n t o f t h e n a t u r e o f t h e a n c i l l a r y l i g a n d s . B e c a u s e o f l i m i t a t i o n s i n s o l u b i l i t y , v a r i a b l e t e m p e r a t u r e e x p e r i m e n t s w e r e d o n e o n l y w i t h [ H 2 R u C l ( P t o l ) 2 ] 2 . ( F i g u r e 4 > 3 ) \u00ab A t 8 0 \u00b0 C - . i n t o l u e n e - d c , t h e ~ h y _ r \u00b1 d e - r e s o n a n c e \" n a r r o w e d t o g i v e a h a l f h e i g h t w i d t h o f 30 H z . ( c o m p a r e d w i t h c a . , 60 Hz a t 3 0 \u00b0 C ) . T h e d o w n f i e l d p o r t i o n o f t h e s p e c t r u m s h o w e d 2 m e t h y l r e s o n a n c e s f r o m + 5 0 \u00b0 C t o - 7 0 \u00b0 C 8 . A l t h o u g h t h e c o m p o u n d w a s i n i t i a l l y c o n s i d e r e d t o b e u n s t a b l e i n c h l o r i n a t e d s o l v e n t s , t h e s p e c t r u m i n C D 2 C 1 2 a t 3 0 \u00b0 C s h o w e d t h e same b r o a d h y d r i d e r e s o n a n c e a t - 1 3 . 3 6 T h i s r e s o n a n c e b r o a d e n e d o n c o o l i n g \" t o ' . - 4 0 \u00b0 G . F u r t h e r c o o l i n g t o - 9 5 \u00b0 C p r o d u c e s t h e s p e c t r u m s h o w n i n F i g u r e 4 .4 , w h i c h e x h i b i t e d t h r e e . d i s c r e t e r e s o n a n c e s a t - 9 . 2 7 ( H ( 1 ) ) , - 1 1 . 6 5 ( H ( 2 ) ) , a n d - 1 9 . 1 5 ( H ( 3 ) ) 6 , w i t h m e a s u r e d r e l a t i v e i n t e n s i t i e s 1 . 2 4 : 1 . 9 4 = 1 ( T a b l e I V - 4 ) . S e l e c t i v e i r r a d i a t i o n o f e a c h h y d r i d e h a d l i t t l e e f f e c t o n t h e r e m a i n i n g r e s o n a n c e s , - 1 1 9 -T A B L E I V - 4 . N . m . r . p a r a m e t e r s 3 \" f o r [ H 2 R u X L 2 ] 2 c o m p l e x e s [ H 2 R u C l ( P t o l 3 ) 2 ] 2 ' ' H - n . m . r . , h y d r i d e ^ . . ' : ( i ) ( i i ) ( i i i ) ( i v ) 3 V{ ' ' 'H} - n . m . r . , p p m C : (.1) ( i i ) ( i i i ) ( i v ) - 1 2 . 8 1 8 ( C g D g , t o l u e n e - d g ; v A = 6 0 H z ) . - 1 3 . 0 5 6 ( t o l u e n e - d 0 ; 8 0 \u00b0 C ; v x = 30 H z ) . o s - 1 3 . 2 8 6 ( 0 D o C l \u201e ; = 60 H z ) . - 9 . 2 7 6 . ( d d , 7 2 H z , ( H z ) ; - 1 1 . 6 5 6 ( V i = 1 2 0 H z ) ; - 1 9 . 1 5 6 ( t , 28 H z ) ( C D 2 C 1 2 ; - 9 5 \u00b0 C ) . 6 7 . 7 , 4 2 . 9 ( C 6 D 6 ) . 6 9 . 2 , 44.0 ( t o l u e n e - d 0 ) . o 7 6 . 9 ( d , 4-0 H z ) ; 6 0 , 4 ( d , 20 H z ) ; 2 7 . 9 ( t o l u e n e - d 0 ) . o 7-4.2 ( d , 40 H z ) ; 5 8 . 3 ( d d , 2 0 H z , 4- H z ) ; 5 6 . 3 ( t d , 40 H z , 4 H z ) ; 3 3 . 5 ( d d , 40 H z , 20 H z ) ; ( C D 2 G 1 2 , - 9 5 \u00b0 C ) . [ H R u C l ( P P h ) ] 3 ' 2 J 2 1 H - n . m . r . , h y d r i d e : - 1 2 . 8 1 6 ( C g D ^ ; v A = 6 0 H z ) . 3 1 P { 1 H } - n . m . r . , p p m : ( i ) 6 8 . . 0 , 4 3 . 1 ( C g D g ) . . ( i i ) 7 3 . 9 ( d , 40 H z ) ; 5 9 , 4 ( d d , 20 H z , 5 H z ) ; 5 5 . 4 ( t d , 40 H z , 5 H z ) ; 2 8 . 0 ( d d , 40 H z , 20 H z ) ; ( C D 2 C 1 2 , - 8 0 \u00b0 C ) . . d [ H 9 R u B r ( P P h 3 ) 2 ( D M A ) ] Q 1 H - n . m . r . , h y d r i d e - 1 2 , 7 3 8 ( C 6 D 6 , V i = 6 0 H z ) -120-T a b l e I V - 4 ( c o n t i n u e d ) . 31 1 P { H } - n . m . r . , p p m : ( i ) 69.5, 44.5 ( t o l u e n e - d 0 ) ( i i ) 7 8 . 2 , 6 1 . 7 , 2 8 . 1 ( t o l u e n e - d Q ; - 6 5 \u00b0 C ) d . [ H ? R u C l ( A s P h 3 ) 2 ( D M A ) ] 1 H - n . m . r . , h y d r i d e : - 1 3 . 8 0 6 ( C g D g ; v A = 60 H z ) 2 [ H 2 R u B r ( A s P h 3 ) 2 ( D M A ) ] 2 -) H - n . m . r . , h y d r i d e : - 1 2 . 6 8 6 . ( ' C ^ D ^ ; V i = 6 0 H z ) a A t 25 \u00b0 C , u n l e s s s t a t e d o t h e r w i s e ; vx r e f e r s t o t h e w i d t h a t h a l f -2 h e i g h t o f t h e b r o a d h y d r i d e r e s o n a n c e , b S e e , f o r e x a m p l e , F i g u r e s 4.3 a n d 4.4. c S e e a l s o F i g u r e s 4.5 a n d 4.7. d S e e A p p e n d i x C . a n d t h e m a j o r c o u p l i n g s o b s e r v e d a r e a s s i g n e d t o J p y T h e H ( 2 ) r e s o n a n c e w a s b r o a d e n e d o n c o o l i n g f r o m 2 0 5 K t o 1 7 8 K . 4 . 2 . 4 - 2 . 3 l P - N . m . r . . . T h e [ H 2 R u C l ( P t o l 3 ) 2 ] 2 c o m p l e x e x h i b i t e d t h e 3 1 P { 1 H } - n . m . r . s h o w n i n F i g u r e 4.5a. A f t e r o n e w e e k , t h e s a m p l e s g a v e s p e c t r a w h i c h d i f f e r e d o n l y i n t h e p r e s e n c e o f t h e p e a k a t 55.5 ppm ( F i g u r e 4.5b) . T h e c o m p o u n d a s s o c i a t e d w i t h t h i s r e s o n a n c e w a s s h o w n t o II ' - C l - a t 4OO M H z . I n s e t s s h o w t h e H ( 1 ) a n d H ( 3 ) r e s o n a n c e s h o r i z o n t a l l y e x p a n d e d . -124-Figure 4.5 P-N.m-.r-. spectra of [H_RuCl(Ptol )_]_ at 30\u00b0C i n C6 D6 a t 4 0 , 5 M H z : ^ broadband proton decoupled of freshly prepared sample; (b) after one week; and (c) selective a r y l p r o t o n * d e : c o u p l i n g o f ( b ) . -125-b e a h y d r i d e b y s e l e c t i v e l y i r r a d i a t i n g t h e p h e n y l r e s o n a n c e s . B a s e d 2 o n J p ^ . (26 H z ) a n d c h e m i c a l s h i f t d a t a , t h e r e s o n a n c e i s a s s i g n e d t o H R u G l C P t o l ^ ) ^ ( S e c t i o n 6.6 ) , w h i c h r e s u l t s f r o m d i s p r o p o r t i o n a t i o n o f t h e d i m e r . O n l o w e r i n g t h e t e m p e r a t u r e ( F i g u r e 4,6), t h e r e s o n a n c e s d u e t o [ H 2 R u C l ( P t o l 3 ) 2 ] 2 b r o a d e n e d a n d c o a l e s c e d a t c a . - 5 5 C . A l t h o u g h some r e s o l u t i o n b e c a m e a p p a r e n t a t - 8 0 \u00b0 C , , t h e l i m i t i n g s l o w e x c h a n g e s p e c t r u m w a s n o t o b t a i n e d i n t h i s s o l v e n t . . H o w e v e r , i n C D 2 C 1 2 a t - 9 5 \u00b0 C , t h e c o m p l e x e x h i b i t e d f o u r d i s c r e t e r e s o n a n c e s a t 74.2 ( P(1)), 58.3 ( P(2)), 56.3 (P(3)), a n d 33.5 (P(4)) ppm ( F i g u r e 4.7a). T h e .. s p e c t r u m d i f f e r s f r o m t h a t a t t h e l o w e s t a v a i l a b l e t e m p e r a t u r e i n t o l u e n e , i n t h e r e l a t i v e p o s i t i o n s o f t h e P(3) a n d P(4) . T h i s m a n i f e s t s - i t . s e l f ^ ' i n - t h e ^ s e p a r a t i o n o f t h e ?(2) ;;p.-u, ?(3) s i g n a l s ; T h i s \u2022 s e p a r a t i o n i s e v e n m o r e p r o n o u n c e d i n t h e P P h ^ a n a l o g u e , [ H g R u C l t P P h ^ ) 2 ] . . u n d e r t h e same c o n d i t i o n s . H o w e v e r , b e c a u s e o f p o o r s o l u b i l i t y , t h e s p e c t r u m c o n t a i n s , s e v e r a l s p u r i o u s p e a k s w h i c h a r i s e e i t h e r f r o m p r e f e r e n t i a l s o l u b i l i t y o f i m p u r i t i e s o r d e c o m p o s i t i o n p r o d u c t s ( s e e A p p e n d i x C ) . T h e s p e c t r u m f o r t h e P t o l ^ d e r i v a t i v e h a s b e e n s i m u l a t e d i n F i g u r e 4 . 8 . B y s e l e c t i v e l y i r r a d i a t i n g t h e p h e n y l p r o t o n s o f t h e P t o l ^ l i g a n d s , t h e s p e c t r u m s h o w n i n F i g u r e 4.7b was o b t a i n e d f o r [ H 2 R u C l ( P t o l 3 ) 2 ] 2 i n C D 2 C 1 2 . 4.2.5., C h e m i c a l r e a c t i o n s . 4.2.5.1. H y d r o g e n c h l o r i d e . A d d i t i o n o f s o l i d s a m p l e s o f [ H 2 R u C l ( P P h ^ ) 9 ] 9 t o DMA s o l u t i o n s - 1 2 6 -6 9 . 2 44.0 30 UC 50\u00b0C 60.4 2 7 . 9 80\u00b0C ^ ^ ^ ^ F i gu re 4.< 31-r1, as a P{ H } - N .m. r . S p e c t r a 0 f [H -RuC l (P to l ).] f u n c t i o n o f temperature i n t o l u e n e - d . a W O . 5 MHz. - 1 2 7 -P (D 7 4 . 2 ppm 4O H z P ( 2 ) 5 8 . 3 ppm 20 H z 4 H z P ( 3 ) 5 6 , 3 ppm 4O H z 4 H z P ( 4 ) 3 3 . 5 ppm 40 H z 2 0 H z F i g u r e # . 7 P-N.m.r. spectra of [fyiuCKPtol ) 2 ] 2 in CD CI at -95\u00b0C at 32.4 MHz under conditions of (a) broadband and (b) selective aryl proton decoupling. - 1 2 8 -31 1 Figure 4.8 Simulated P{ H}-n.m.r. spectrum of [H\u201eRuCl(Ptol0)J. in 2 3 2 J 2 slow exchange using couplings shown in the inset.. of DMA\u00ab,HC1 under argon resulted in a rapid gas evolution corresponding to 1.5 mole of gas per mole of ruthenium. In a separate experiment, DMA (5.0 mL) containing DMA.'HCl (100 mg, 0.81 mmol) was injected into a sealed evacuated Schlenk tube (total volume 15 mL) containing [H 2RuCl(PPh 3) 2] 2 (500 mg, 0.75 mmol Ru). After 20 minutes, the gas above the solution was sampled, and found, by g.l.c. analysis, to contain hydrogen. Because of sampling techniques, the amount of 31 1 hydrogen was not quantified. The P{ H)-n.m.r. spectrum of the f i n a l solution resulting from reaction of [R^RuCltPPh^) 2] 2 (4O mg, 0.06 mmol) with excess DMA*HC1 (4O mg, 0.32 mmol, 5 equivalents) i n DMA:toluene-dg (1:1 v\/v) showed the major product to be Ru2Cl^(PPh.j) j~ (48 ppm, AB pattern, ^g= 36 Hz) (Figure 4.9) presumably with DMAH+ as the . ; ; ; ; : : ' : r : : | | \u2022 \u2022 \u2022 \u2022 ' \u2022 1 \u2022 \u2022 \u2022 1 1 ] . . 1 \u2022 i \u2022 1 - i - : - : ; : l \" \" : \" \" | ' : : : : : : T : i : : T : 4 8 ppm 144 ppm i . . . . i i i . . . . . . . i . . i : : : : : : : i . . . . i . . . F i g u r e 4.9 \" \" P { ' H } - N . m . . r ~ . s p e c t r u m o f r e a c t i o n p r o d u c t s o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 w i t h DMA.HC1 ( - 6 5 \u00b0 C ) . c o u n t e r c a t i o n . T h e e x i s t e n c e o f a s e c o n d t e m p e r a t u r e i n v a r i a n t r e s o n a n c e a t 44 ppm ( s i n g l e t ) i n d i c a t e d t h e p r e s e n c e o f a n o t h e r s p e c i e s , t h e n a t u r e o f w h i c h c o u l d n o t b e d e t e r m i n e d , e x c e p t t o 31 n o t e ( b y P { p h e n y l } - n . m . r . e x p e r i m e n t s ) t h a t i t w a s n o t h y d r i d i c . T h i s s p e c i e s w a s a l s o g e n e r a t e d b y . a d d i n g e x c e s s D M A ' - H C l t o D M A : t o l u e n e - d g ( 1 : 1 v \/ v ) s o l u t i o n s o f [ R u C l ^ P P h ^ ) ^ o r R u C l ^ P P h ^ a n d s o a p p a r e n t l y a r i s e s f r o m a s e c o n d a r y r e a c t i o n b e t w e e n D M A . H C 1 a n d R u n C l - ( P P h J \" . 2 5 3 4 4 . 2 . 5 . 2 . 2 , 2 ' - B i p y r i d i n e . A d d i t i o n o f s o l i d s a m p l e s o f [ H 2 R u C l P 2 ] 2 ( P = P P h ^ , P t o l ^ ) t o t o l u e n e o r DMA s o l u t i o n s o f b i p y r i d i n e u n d e r a r g o n r e s u l t e d i n a s l o w g a s e v o l u t i o n c o r r e s p o n d i n g t o 0.5 m o l e g a s p e r m o l e r u t h e n i u m . - 1 3 0 -B e n z e n e ( 5 mL) w a s i n j e c t e d i n t o a s e a l e d e v a c u a t e d S c h l e n k t u b e ( t o t a l v o l u m e 15 mL) c o n t a i n i n g [ H g R u C l t P P h ^ ) ^ ( 5 0 0 m g , 0 . 7 5 m m o l R u ) a n d 2 , 2 ' - b i p y r i d i n e ( 5 5 0 m g , 3 . 5 3 m m o l ) . - T h e r e d s u s p e n s i o n d a r k e n e d t o b r o w n . A f t e r 20 m i n u t e s , t h e g a s a b o v e t h e s o l u t i o n w a s s a m p l e d a n d f o u n d b y g . l . c . a n a l y s i s , t o c o n t a i n h y d r o g e n . T h e s u s p e n s i o n w a s t r a n s f e r r e d t o a l a r g e r S c h l e n k t u b e , w i t h t h e a d d i t i o n o f b e n z e n e ( 2 0 mL) a n d s t i r r e d f o r 1 8 h o u r s , a f t e r w h i c h i t w a s f i l t e r e d , w a s h e d w i t h d i e t h y l e t h e r a n d ' v a c u u m d r i e d ( i s o l a t e d y i e l d : 4.00 m g ; 6 5 $ ) . T h e p r o d u c t w a s i d e n t i f i e d a s t h e c o m p o u n d [ H R u C l ( b i p y ) ( P P h ^ ^ ^ d e s c r i b e d b y W i l k i n s o n 2 7 , b y e l e m e n t a l a n a l y s i s ( c a l c u l a t e d f o r C - ^ H ^ N ^ l P ^ R u r - C : 6 7 . 5 2 ; H : 4.80; N : 3.42$; f o u n d ; G : 6 7 . 8 0 ; H : 4 - 8 5 ; N : 3 - 3 5 $ ) a n d H - n . m . r . ( h y d r i d e r e s o n a n c e i n 2 1 ~ C D G l ^ a t - 1 2 . 3 6 , t , J p ^ = 2 5 H z ) . T h e H - n . m . r . - s p e c t r u m a l s o s h o w e d t h e a p p a r e n t p r e s e n c e o f a s e c o n d h y d r i d e i n m u c h l o w e r y i e l d ( c a . 15$-; - 1 3 . 1 9 6 , d o u b l e t (30- H z ) o f d o u b l e t s ( 2 9 H z ) ) . 4 . 2 . 5 . 3 . C a r b o n m o n o x i d e . A d d i t i o n o f c a r b o n m o n o x i d e g a s a t 1 a t m t o r e d s o l u t i o n s 2 o f [ H ^ R u C ^ P P h ^ g ^ i n t o l u e n e ( 1 0 M) r e s u l t e d i n r a p i d g a s u p t a k e c o r r e s p o n d i n g t o 1 . 5 e q u i v a l e n t s o f g a s p e r e q u i v a l e n t o f r u t h e n i u m a t o m , c o n c o m i t a n t ' ' w i t h a c o l o r c h a n g e t o p a l e y e l l o w . I n DMA -'\u20222 - 3 s o l u t i o n s (-2 x. ' I .O i.c; .4 x 10 \u2022 _ ) , u p t a k e s c o r r e s p o n d e d t o 1 . 7 t o 2 . 0 m o l e s o f g a s p e r m o l e o f r u t h e n i u m a t o m , t h e s l i g h t l y l o w e r v a l u e s b e i n g o b t a i n e d a t t h e h i g h e r c o n c e n t r a t i o n s . I n s e p a r a t e e x p e r i m e n t s , b e n z e n e a n d DMA ( 5 . 0 mL e a c h ) w e r e , i n j e c t e d i n t o e v a c u a t e d s e a l e d S c h l e n k t u b e s ( t o t a l V o l u m e . 1 5 mL) c o n t a i n i n g J [ H 2 R u C l ( P P h q ) ? ] ? ( 5 0 0 m g , 0.76 mmol). The t o t a l pressure was made up to one atmosphere with CO, and the system sealed. A f t e r 30 minutes, the c o l o r paled to yellow-orange, and the gas was sampled. In both cases, g . l . c . a n a l y s i s i n d i c a t e d the presence of H^. A d d i t i o n of CO to samples of [ H 2 R u C l ( P P h 3 ) 2 ] 2 (30 mg, 0.05 mmol) i n C^Dg (0.5 mL) caused the formation of HRuCl(C0) 2(PPh.j) 2, which was i d e n t i f i e d by i t s hydride resonance (-3.865, t , 20Hz) and 3 1P{ 1H} n.m.r. s h i f t (39.9 ppm) ( Table 31 1 II-1 ). In a d d i t i o n , the P{ H}-n.m.r. spectrum of the product (Fig u r e 4.10 ) showed the presence of small equimolar amounts of R u ( C 0 ) 3 ( P P h 3 ) 2 (55.4 ppm) and R u C l 2 ( C 0 ) 2 ( P P h 3 ) 2 (16.2 ppm). These were i d e n t i f i e d by comparing the chemical s h i f t s w i t h those of aut h e n t i c samples, and, i n the case of R u ( C 0 ) 3 ( P P h 3 ) 2 , by s o l u t i o n i . r . (toluene, v c o 1900 cm\" 1). The product a n a l y s i s i n DMA was c a r r i e d out analogously. [ H 2 R u C l ( P P h 3 ) 2 ] 2 (35 mg, 0.05 mmol) was shaken under one atmosphere ^ i i | i | i < | i | i , i | i H i | i | i , ( i | i , i , i H i , i | i ; | i , i l i | i H i , i | i j l 55.4- ppm 39.9 ppm 16.2 ppm I ' l ' l ' l ' l 'l \\ \\ '. I I I It I1 I 1 I ' l ' l ' l ' l ' l ' l ' l 'l 'l '| * \\ | | | \\ I ( j |' I ' l ' l ' l ' l ' , ' ! ' ! '| '| \\ \\ | | | | I ,' j ,1 I, I, \\ ^44+ \" ' 1 1 1 I I I I I I I I I I | 1 I I I | I | | I | I I I I | 1 | | | | I I I I I .1 I I I I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I I 1 1 1 1 1 1 1 1 1 1 1 1 1 \\ Figure A.10 P{ H) n.m.r. spectrum of the reaction products of [H 2RuCl(PPh 3) 2] 2 with CO in C ^ at 30\u00b0 C. \u2022 1 3 2 -o f CO i n DMA ( 0 . 3 mL) f o r 2 h o u r s . A f t e r t h e a d d i t i o n o f C ^ D g u n d e r 31 1 C O - ( t o p r o v i d e t h e d e u t e r i u m l o c k ) , t h e s o l u t i o n e x h i b i t e d a P { H } -n . m . r . s p e c t r u m v i r t u a l l y i d e n t i c a l w i t h t h a t s h o w n i n F i g u r e 4.10 . 4 . .2 . 5.4 P h o s p h i n e s . A d d i t i o n o f P P h ^ t o e i t h e r ( a ) i s o l a t e d s a m p l e s o f [ H ^ R u C l t P P h ^ ) 2 J 2 u n d e r a r g o n , o r ( b ) [ H 2 R u C l ( P P h 3 ) 2 ] 2 g e n e r a t e d \u00b1n s i t u ( a f t e r R u C l ( P P h 3 ) 2 . D M A h a d r e a c t e d w i t h H 2 a t 3 0 \u00b0 C i n t h e p r e s e n c e o f 15 e q u i v a l e n t s - o f P r o t o n : S p o n g e \u00ae f o r 1 0 , 0 0 0 s e c o n d s ) u n d e r E^, b o t h r e s u l t e d i n n e t g a s e v o l u t i o n c o r r e s p o n d i n g t o 0 . 5 e q u i v a l e n t s . A s b e f o r e , i n s e p a r a t e e x p e r i m e n t s , b e n z e n e a n d . D M A ( 5 . 0 mL e a c h ) w e r e i n j e c t e d i n t o e v a c u a t e d s e a l e d S c h l e n k t u b e s ( t o t a l v o l u m e 15 mL) c o n t a i n i n g [ H 2 R u C l ( P P h 3 ) 2 J 2 ( 5 0 0 m g , 0 . 7 6 m m o l ) a n d P P h 3 ( 5 0 0 m g , 1 .91 m m o l , 2 . 5 e q u i v a l e n t s ) . . T h e s o l u t i o n s c h a n g e d f r o m r e d t o v i o l e t . A f t e r 1 5 m i n u t e s , t h e g a s a b o v e the . , r e a c t i o n m i x t u r e w a s s a m p l e d a n d f o u n d t o c o n t a i n h y d r o g e n . T h e p r o d u c t w a s i d e n t i f i e d a s H R u C l ( P P h 3 ) 3 \u2014 1 \u2014 1 1 b y v i s i b l e s p e c t r o s c o p y ( A ~ 5 2 0 n m , .\u00a3 = 1 6 5 0 M cm ) a n d t h e H -0 J max n . m . r . o f t h e i s o l a t e d s o l i d . ( 6 ( R u - H ) - \/ ( C D C l 3 ) , - 1 7 . 7 5 , t , 26 H z ) . T h e k i n e t i c s o f t h e r e a c t i o n b e t w e e n [ H 2 R u C l ( P t o l 3 ) 2 J 2 a n d P t o l 3 w e r e c o n v e n i e n t l y s t u d i e d i n DMA a t . 3 0 \u00b0 C u n d e r h y d r o g e n , b y m o n i t o r i n g t h e s p e c t r a l c h a n g e s a t 5 6 0 n m . R e p r e s e n t a t i v e s p e c t r a l c h a n g e s a r e s h o w n i n F i g u r e 4,11.. I n c o n t r a s t w i t h t h e m e t h o d s u s e d i n C h a p t e r 5 s t o c k r u t h e n i u m s o l u t i o n s w e r e n o t p r e p a r e d , b e c a u s e t h e r e w a s some d o u b t a s t o t h e i r s t a b i l i t y o v e r , e x t e n d e d p e r i o d s o f t i m e . T h e a m o u n t o f [ H 2 R u C l ( P t o l _ ) 2 ] 2 r e q u i r e d f o r e a c h e x p e r i m e n t w a s w e i g h e d o u t s e p a r a t e l y . S t o c k s o l u t i o n s o f P t o l - i n DMA w e r e u s e d , h o w e v e r . T h e r u t h e n i u m c o m p o u n d was d i s s o l v e d i n DMA (4 . O mL) u n d e r o n e a t m o s p h e r e - 1 3 3 -7 0 0 7 5 0 W a v e l e n g t h , n m . F i g u r e 4 . 1 1 S p e c t r a l c h a n g e s a c c o m p a n y i n g t h e r e a c t i o n o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 w i t h P t o l _ i n DMA a t 3 0 \u00b0 C u n d e r H . o f h y d r o g e n i n t h e c e l l . O n c e ' t h e d i m e r l i a ' d d i s s o l - v e . d - , \u2022 s o l u t i o n s o f P t o l - ( i n 1 . 0 mL) w e r e a d d e d t o t h e u n t h e r m o s t a t t e d s i d e a r m f l a s k s e p a r a t e f r o m t h e r u t h e n i u m s o l u t i o n ( C h a p t e r 2, F i g u r e 2 . 4 ) a n d t h e a p p a r a t u s w a s c h a r g e d w i t h t h e r e q u i r e d p r e s s u r e o f h y d r o g e n . T h e r u t h e n i u m s o l u t i o n s w e r e e q u i l i b r a t e d a t 3 0 \u00b0 C f o r 1 0 m i n u t e s , i n t h e t h e r m o s t a t t e d c e l l c o m p a r t m e n t , a f t e r w h i c h t i m e t h e y w e r e m i x e d b y s h a k i n g t o g e t h e r . M i x i n g t i m e w a s l e s s t h a n 1 0 s e c o n d s , b u t t h e r m a l e q u i l i b r a t i o n t o o k l o n g e r . T h e f a s t e r r e a c t i o n s s h o w e d some d e v i a t i o n s f r o m l i n e a r i t y i n t h e i n i t i a l p a r t s o f t h e p s e u d o f i r s t - o r d e r r a t e p l o t s . T h e s e d e v i a t i o n s o c c u r r e d i n t h e f i r s t 1 0 0 s e c o n d s o f t h e r e a c t i o n r e g a r d l e s s o f a n d c o r r e s p o n d e d t o t h e t i m e s h o w n b y t h e d i g i t a l t h e r m o s t a t t o r e a c h t h e r m a l e q u i l i b r i u m . T h e d a t a d u r i n g t h e s e t i m e s w e r e n o t u s e d i n c a l c u l a t i o n s o f k ^ , O n c e t h i s t h e r m a l e q u i l i b r i u m w a s - 1 3 4 -r e a c h e d , t h e c e l l s c o u l d b e p e r i o d i c a l l y r e m o v e d a n d s h a k e n w i t h n o s i g n i f i c a n t t e m p e r a t u r e v a r i a t i o n . T h i s p r o c e s s w a s n e c e s s a r y t o e n s u r e a c o n s t a n t s o l u t i o n c o n c e n t r a t i o n o f d u r i n g t h e c o u r s e o f t h e r e a c t i o n . T h e r e s u l t s a r e s u m m a r i z e d i n T a b l e I V - 5 a n d F i g u r e s 4.12 a n d 4 . 1 3 . T h e r e a c t i o n was f i r s t o r d e r i n r u t h e n i u m , p l o t s o f l n C A ^ - A ) v s . t i m e b e i n g l i n e a r o v e r a t l e a s t t w o h a l f l i v e s ( s e e A p p e n d i x D ) , [ P t o l . ] x 1 0 2 , M F i g u r e 4.12 D e p e n d e n c e o f k . ^ g o n P t o l - c o n c e n t r a t i o n f o r t h e r e a c t i o n o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 w i t h P t o l i n DMA a t 3 0 \u00b0 C ( [ R u ] = 5 . 9 x 1 0 ~ 4 M; [ H _ ] = 1 . 6 0 x 1 0 _ 3 M ) . - 1 3 5 -T A B L E IV.-'5. K i n e t i c d a t a & f o r t h e r e a c t i o n b e t w e e n . . [ H - R u C l ( P t o l - ) _ ] - a n d P t o l - i n DMA a t 3 0 \u00b0 C . [ R u ] b x 1 0 4 , . ' . . [ P t o l j x I O 2 , . [ H 0 ] x 1 0 4 , k , x 1 0 3 , k _ \" 1 , \u2022 - 3 2 o b s 1 o b s M M M \u2022 s s 1 . 2 0 2 . 9 8 , . 1 6 , 0 4 . 5 4 -3.48 2 . 9 8 . 1 6 . 0 4.44 -5 . 6 2 2 . 9 8 1 6 . 0 4 . 2 4 -5 . 8 9 2 . 9 8 1 6 . 0 4 . 4 9 -1 8 . 5 2 . 9 8 . 1 6 ' . 0 4 . 0 9 -5 . 9 0 . 5 1 : 1 6 . . 0 . 0 . 7 8 -5 . 9 1 . 6 9 1 6 . 0 - 2 . 4 5 -5 . 9 4 . 0 5 , 1 6 . 0 5 . 6 6 -5 . 9 4 . 8 5 1.6.0 7 . 1 3 -5 . 9 6 . 1 7 1 6 . 0 8.62 -5 . 9 1 . 0 2 . , . 1 6 . 0 . 1 . 4 2 \u00b0 7O4 5 . 9 1 . 0 2 1 1 . 6 1 . 9 7 5 0 7 5 . 9 1 . 0 2 9 . 4 7 2.46 4 1 0 5 . 9 1..02 8 . 0 0 . . 2 . 9 8 3 3 5 5 . 9 1 . 0 2 . . 5 . 2 6 . 4 . 1 0 2 4 4 5 . 9 1 . 0 2 . 4 . 6 3 \u2022 4 . 9 4 2 0 2 5 . 9 1 . 0 2 .. 3 , 4 5 . 5 . 8 1 171 5 . 9 1 . 0 2 , 3 . 0 3 6 . 8 7 U 5 a M e a s u r e d a t 5 6 0 n m . D a t a g i v e n i n A p p e n d i x D . b E x p r e s s e d i n . t e r m s --0 , f > r u t h e n i u m a t o m s . c I n t e r p o l a t e d f r o m t h e p l o t o f k , v s . [ p t o l \u201e ] - 1 3 6 -a n d k o b s W S S i n d e P e n d e n ' f c o f r u t h e n i u m c o n c e n t r a t i o n . T h e r e a c t i o n w a s s t r i c t l y f i r s t - o r d e r i n p h o s p h i n e c o n c e n t r a t i o n a n d s h o w e d a d i r e c t i n v e r s e f i r s t - o r d e r i n h y d r o g e n c o n c e n t r a t i o n o v e r t h e c o n c e n t r a t i o n r a n g e s t e s t e d . 8 0 0 ra O 2 0 0 H 0 . 4 0 . 8 1 . 2 [H ] x 1 0 3 , M 1 . 6 F i g u r e 4 . 1 3 D e p e n d e n c e o f k Q b g o n h y d r o g e n c o n c e n t r a t i o n f o r t h e r e a c t i o n o f [ H 2 R u C l ( P t o l 3 ) 2 J 2 w i t h P t o l i n DMA a t 3 0 \u00b0 C ( [ R u ] = 5 . 9 x 1 0 \" 4 M ; [ P t o l ] = 1 . 0 2 x 1 0 _ 2 M ) . - 1 3 7 -4.3-> D i s c u s s i o n . On t h e b a s i s o f u p t a k e s t o i c h i o m e t r i c s . , ' n . m . r . , a n d c h e m i c a l r e a c t i o n s . , - t h e : c o m p o u n d s V i s 6 l a t e d \" ' f r o m t h e \" r e a c t i o n o f R u X ^ L ^ (X. = C I , B r ; L = P P h ^ , P t o l y A s P h ^ ) a n d o t h e r b l ' s C p h o s p h i n e ) p r e c u r s o r s , ( [ R u C l 2 ( P P h - 3 ) ? ] [ R u C l ( D M - ) ( P P h 3 ) 2 C C : l 2 ^ 2 , . H R u C l ( n b d ) ( P P h 3 ) ? ) w i t h m o l e c u l a r h y d r o g e n i n t h e p r e s e n c e o f s t r o n g b a s e s h o u l d b e r e f o r m u l a t e d a s h a v i n g t h e e m p i r i c a l f o r m u l a e [ H 2 R u X L 2 J 2 . . T h e s p e c t r a l p r o p e r t i e s f o u n d f o r [ H 2 R u C l P 2 ] 2 ( P = P P h y P t o l ) a r e s u f f i c i e n t l y c l o s e t o t h o s e d e s c r i b e d b y W a n g ? a a n d T h o r b u r n 8 f o r t h e p r e s u m e d [ H R u C l P 2 ] 2 c o m p l e x t o i n d i c a t e t h a t t h e s e w o r k e r s w e r e , i n f a c t , s t u d y i n g t h e t e t r a h y d r i d o d i m e r . T h o r b u r n 8 w a s f o r t u n a t e e n o u g h t o o b t a i n c r y s t a l s s u i t a b l e f o r X - r a y a n a l y s i s f r o m a p r e p a r a t i o n o f t h e c h l o r o - t r i ( p _ - t o l y l ) p h o s p h i n e d e r i v a t i v e . A l t h o u g h p o o r l y r e f i n e d 1 1 3 , d-u^ : t o . . d e c o m p o s i t i o n . : o f - t h e c r y s t a l d u r i n g d a t a a c c u m u l a t i o n , t h e d a t a s h o w e d t h e c h l o r o b r i d g e d d i m e r s h o w n i n F i g u r e 5 . 1 4 . - T h e d i s t a n c e b e t w e e n t h e r u t h e n i u m c e n t e r s ( 2 . 8 0 A) f a l l s w i t h i n t h e r a n g e u s u a l l y f o u n d f o r a R u - R u s i n g l e b o n d ( 2 . 2 8 t o 2 . 9 5 S ) 1 2 3 - 1 2 9 , A l s o , t h e R u ( l ) - C l ( l ) - R u ( 2 ) a n d R u ( 1 ) - C l ( 2 ) - R u ( 2 ) a n g l e s a r e 6 9 . 3 \u00b0 a n d 6 7 . 3 \u00b0 r e s p e c t i v e l y . I n o t h e r c o m p l e x e s w h i c h c o n t a i n s u c h M 2 X 2 r i n g s ( X i s t h e d o n o r a t o m o f t h e b r i d g i n g l i g a n d ) , \" s h a r p l y a c u t e \" M - X - M a n g l e s o f t h i s n a t u r e a r e t a k e n , t o b e c h a r a c t -e r i s t i c - o f M - M - b o n d i n g - 1 . 2 , 8 . - A t t h e t i m e , t h e s t r u c t u r e - w a s d o n e , . t h e c o m p o u n d w a s c o n s i d e r e d t o b e [ H R u C l ( P t o l 3 ) 2 ] 2 a n d t h e a p p a r e n t e x i s t e n c e o f s u c h a b o n d l e d t o some d o u b t a s t o w h e t h e r o r n o t t h i s s t r u c t u r e w a s r e p r e s e n t a t i v e o f t h e b u l k o f . t he c o m p l e x . T h e e x i s t e n c e o f t h e b o n d n o w e x p l a i n s t h e o b s e r v e d d i a m a g n e t i s m o f t h e - 1 3 8 -P(3) P(4) Distance (2) R U ( 1 ) R U ( 1 ) R U ( 1 ) R u ( 2 ) Ru(2) R u ( 1 ) R u ( 1 ) Ru(2). Ru(2). -Ru(2) -P(D -P(3) -P(2) -P(4) -C1(1) -Cl(2) \u2022C1(1) -Cl(2) 2.80(0) 2 . 2 3 ( 1 ) 2 . 2 8 ( 1 ) 2 . 2 6 ( 1 ) 2 . 3 9 ( 1 ) 2 . 4 6 ( 1 ) 2 . 5 7 ( 1 ) 2 . 4 7 ( 1 ) 2 . 4 8 ( 1 ) Angles (deg) P(1)-RU(1)-P(3) P(1)-RU(1)-C1(1) P ( 1 ) - R U ( 1 ) - C l ( 2 ) P(1)-RU(1)-Ru(2) P(3)-RU(1)-C1(1) P(3)-RU(1)-Cl(2) P(3)-RU(1)-Ru(2) P(2)-Ru(2)-P(4) P(2)-RU(2)-C1(1) P(2)-Ru(2)-Cl(2) P(2)-RU(2)-RU(1) P(4)-RU(2)-C1(1) P(4)-Ru(2)-Cl(2) P(4)-RU(2)-RU(1) RU(1)-C1(1)-RU(2) RU(1)-Cl(2)-Ru(2) 97.6(5) 166.8(5) 94.4(5) 111.9(4) 95.6(5) 113.8(4) 1 4 8 . 4 ( 4 ) 104.1(5) 92.1(5) 167.6(5) 110.0(4) 102.9(4) 8 8 . 0 ( 4 ) 139.3(3) 69.3(4) 67.3(3) Figure 4.U C r y s t a l s t r u c t u r e of [H-R\u00abCl(Ptol and s e l e c t e d bond angles and d i s t a n c e s . - 1 3 9 -[ H ^ R u C l C P t o l ^ ) c o m p l e x , a n d i t i s r e a s o n a b l e t o a s s u m e t h a t t h e s t r u c t u r e i s t h a t o f t h e t e t r a h y d r i d e . T h e d i s t o r t i o n s f r o m i d e a l i z e d s y m m e t r y h a v e b e e n a t t r i b u t e d t o t h e h y d r i d e l i g a n d s , a l t h o u g h t h e p o s i t i o n s o f t h e s e c o u l d n o t b e d e t e r m i n e d . . M o l e c u l a r w e i g h t m e a s u r e m e n t s i n b e n z e n e s h o w t h a t t h e d i m e r i c f o r m p e r s i s t s i n t h i s s o l v e n t , a s m i g h t b e e x p e c t e d f o r a m e t a l - m e t a l , b o n d e d c o m p l e x . T h e f a c t t h a t t h e P { ' H } - n . m . r . s p e c t r a o f [ H 2 R u C i ( P t o l ) 2 ] 2 a r e i d e n t i c a l i n GD^Gl^y GgDg. - , . - to - luene t -dg , : ; a n d D M A \/ t o l u e n e - d g m i x t u r e s - s u g g e s t s t h a t t h e d i n u c l e a r i t y . i s m a i n t a i n e d a l s o i n t h e s e - ^ s o l v e n t s , a t l e a s t a t t h e h i g h e r c o n c e n t r a t i o n s r e q u i r e d f o r t h i s m e t h o d . T h e r e s o n a n c e a t 5 8 . 5 \"ppm prev lous - ly^obse-Eved.. ? \u2022 ' . a t - h i g h e r . t e m p e r a t u r e s - a n d a s s i g n e d t o m o n o m e r H R u C l C P t o l ^ ) 2 a r i s e s f r o m d e c o m p o s i t i o n o f t h e d i m e r a n d i s i n s t e a d t h e t r i s ( p h o s p h i n e ) s p e c i e s H R u C l ( P t o l , j ) ^ ( S e c t i o n 6 . 6 ) . A l t h o u g h n o t r e p o r t e d , t h e r e w a s a o n e w e e k d e l a y i n o b t a i n i n g t h e h i g h t e m p e r a t u r e s p e c t r a i n t h e p r e v i o u s w o r k 1 3 0 . T h e v i s i b l e s p e c t r a , o f [ H 2 R u G . l ( P t o l ) 2 J 2 a t 5 x 1 0 \" ^ M i n t o l u e n e a n d DMA a r e v i r t u a l l y i d e n t i c a l , i m p l y i n g a g a i n t h a t t h e s p e c i e s i s t h e same i n b o t h s o l v e n t s . B e e r ' s L a w p l o t s i n DMA o f [ H 2 R u C l P 2 ] 2 ( p = P P h ^ , P t o l ^ ) w e r e l i n e a r a n d g a v e n o i n d i c a t i o n o f a m o n o m e r -d i m e r e q u i l i b r i u m , a s s u g g e s t e d b y T h o r b u r n 8 . T h e v a r i a t i o n s o b s e r v e d p r e v i o u s l y c o u l d h a v e b e e n d u e ' - t o u n r e c o g n i z e d s o l u t e d e c o m p o s i t i o n b y , ' D M A - w h i c h . ' b e c o m e s - . - r e l a t i v e l y . . m o r e s i g n i f i c a n t a t l o w e r c o n c e n t r a t i o n . T h e e x i s t e n c e o f a s o l v a t e d m o n o m e r a s f i r s t s u g g e s t e d b y W a n g s e e m s u n l i k e l y i n v i e w o f t h e s i m i l a r i t y o f v i s i b l e s p e c t r a i n t o l u e n e a n d D M A , T h e e v i d e n c e - f o r t h i s p r e v i o u s a s s i g n m e n t r e a l l y d o e s n o t d i f f e r e n t i a t e t h e n u c l e a r i t y o f t h e s p e c i e s 7 a . I n t r y i n g t o d e t e r m i n e t h e , n a t u r e o f t h e c o m p o u n d , l o w t e m p e r a t u r e n . m . r . h a s g i v e n c o n s i d e r a b l e f u r t h e r i n f o r m a t i o n , . ' p a r t i c u l a r l y w i t h -UO-r e g a r d t o t h e p r o b a b l e p o s i t i o n s o f t h e h y d r i d e s . B y u s i n g C D ^ C l ^ , 3 \"I 1 i t w a s p o s s i b l e t o o b t a i n t h e l i m i t i n g s l o w e x c h a n g e P { H } - n . m . r . s p e c t r u m ( F i g u r e 4 .,7) w h i c h s h o w s t h a t t h e r e a r e f o u r d i f f e r e n t p h o s p h o r u s a t o m s i n t h e i n t e n s i t y r a t i o 1 : 1 : 1 : 1 , n u m b e r e d i n o r d e r o f c h e m i c a l s h i f t , i n t h e r e g i o n n o r m a l l y f o u n d f o r r u t h e n i u m - t r i a r y l -p h o s p h i n e c o m p o u n d s 3 3 ' 6 8 . O f t h e s e , P ( 3 ) i s c o u p l e d t o a l l o t h e r p h o s p h o r u s a t o m s , w h i l s t P ( l . ) i s c o u p l e d O n l y t o P ( 3 ) . P ( 2 ) a n d P(4-) a r e c o u p l e d t o o n e a n o t h e r a s w e l l - , a s t o . P ( 3 ) . T h e r e s o n a n c e s a r e s u f f i c i e n t l y s e p a r a t e d t h a t t h e c o u p l i n g c o n s t a n t s c a n b e m e a s u r e d d i r e c t l y . T h e c o u p l i n g p a t t e r n i s s i m u l a t e d a n d p r e s e n t e d s c h e m a t i c a l l y i n F i g u r e 4'.8*. T h e n . m . r . p a r a m e t e r s a p p e a r t o b e w h o l l y c o n s i s t e n t w i t h t h e a s y m m e t r i c u n i t d e s c r i b e d e r y s t a l l o g r a p h i c a l l y . T h e P { H } -n . m . r . .\u2022 s p e c t r u m ' i s a t t r i b u t a b l e t o . a, s i n g l e , c o m p o u n d b y . J a s s u m i ' n g t h a t some p h o s p h i n e s ' o n a d j a c e n t \" - r u t h e n i u m , c e n t e r s - a r e c o u p l e d t o o n e - a n o t h e r , 1 . T h e v a l u e s - . f o u n d f o r . ' J p p ' . i n d i c a t e \" ' t h a t n o p h o s p h i n e s a r e t r a n s d i s p o s e d . T h e - ' u p f i e l d s h i f - t ' I o f P ('-'4-)\" and- t h e m e a s u r e d J ( ) P (4.) a r e c o n s i s t e n t w i t h , t h e s e l i g a n d s . ' b e i n g t r a n s ' t o o n e a n o t h e r 1 3 1 \u00bb 1 3 2 . T h e d o w n f i e l d p o s i t i o n o f H ( 1 ) i s s i m i l a r l y c o n s i s t e n t . T h e a b s e n c e 31 o f a n y f u r t h e r b r o a d e n i n g o f t h e P(4-) r e s o n a n c e i n t h e P { . p h e n y l } s p e c t r u m ( F i g u r e 4;-7b) i n d i c a t e s t h a t t h i s p h o s p h i n e i s c o u p l e d t o t h e s i n g l e h y d r i d e , H ( l ) . T h e r e s o n a n c e d u e t o H ( 1 ) , h o w e v e r , s h o w s a d d i t i o n a l f i n e s t r u c t u r e ( F i g u r e 4.4) i n d i c a t i n g a w e a k i n t e r a c t i o n w i t h a t l e a s t o n e o t h e r p h o s p h i n e . B e c a u s e t h e P ( 2 ) a n d P ( 3 ) r e s o n a n c e s o v e r l a p , . and t h e v a l u e s o f J_\u201e a n d . J a r e c o m p a r a b l e t o t h e l i n e -rxl nrl w i d t h s o f t h e s p e c t r a , , t h e r e m a i n i n g a s s i g n m e n t s a r e m o r e a m b i g u o u s . T h e c h e m i c a l s h i f t s o f h y d r i d e s , i n some c a s e s , s h o w t r e n d s w h i c h c o r r e l a t e w e l l w i t h e n v i r o n m e n t , a n d a r e s o u s e d i n a s s i g n i n g t h e i r - I m -p o s i t i o n s 1 ^ W h e n h y d r o g e n i s t r a n s t o a l i g a n d o f l o w t r a n s i n f l u e n c e , i t s c h e m i c a l s h i f t i s a t h i g h f i e l d ( - 1 0 6 o r a b o v e ) , w h i l e o p p o s i t e a l i g a n d o f h i g h t r a n s i n f l u e n c e , i t s c h e m i c a l s h i f t i s a t t h e l o w e r p a r t ( < - 1 0 6 ) . o f t h e h i g h f i e l d r e g i o n ( e . g . , H ( l ) i n t h i s c a s e ) . S o m e . w o r k e r s h a v e s u g g e s t e d t h a t , \" i n g e n e r a l \" , b r i d g i n g h y d r i d e s r e s o n a t e a t . h i g h e r f i e l d s r t h a n d o t e r m i n a l o n e s . H o w e v e r , t h e s e e m p i r i c i s m s a r e m o r e u s e f u l f o r - a f t e r t h e f a c t r a t i o n a l i z a t i o n s , r a t h e r t h a n - f o r p r e d i c t i n g ; a s s i g n m e n t s b a s e d o n c h e m i c a l s h i f t d a t a a l o n e a r e m e a n i n g l e s s . T h e a p p e a r a n c e a n d s h a p e o f H(3) ( F i g u r e 4.4, 1 : 2 : 1 t r i p l e t , 2 J = 28 H z ) i n d i c a t e t h a t i t rn m u s t b e c o u p l e d e q u a l l y d i r e c t l y t o -two p h o s p h o r u s n u c l e i , s i n c e i n 31 31 n o c a s e i s J ( P - P ) l a r g e e n o u g h t o i n t r o d u c e s u f f i c i e n t d e c e p t i v e s i m p l i c i t y t o g i v e a n - a p p a r e n t l y n o r m a l 1 : 2 : 1 t r i p l e t p a t t e r n . B y v i r t u e o f t h e m a g n i t u d e ' o f J p ^ ( 2 8 H z ) , t h e s e - a r e m o s t l i k e l y t o 31 b e P ( 1 ) a n d P ( 3 ) - ( t h e ;> E f p h e n y l } \u2022 r e s o n a n c e f o r P ( 2 ) c a n n o t a c c o m m o d a t e s u c h a l a r g e v a l u e ) . 31 1 T h e l o w t e m p e r a t u r e P{ H } - n . m . r . s p e c t r u m s h o w s a m u c h w i d e r r a n g e o f c h e m i c a l s h i f t s t h a n w o u l d , b e e x p e c t e d b a s e d o n t h e a v a i l a b l e c r y s t a l l o g r a p h i c d a t a , i n d i c a t i n g a n e v e n h i g h e r d e g r e e o f a s y m m e t r y . T h a t i s , t h o u g h d i s t o r t e d s l i g h t l y , t h e s o l i d s t a t e s t r u c t u r e s h o w s a n a p p r o x i m a t e a x i s b e t w e e n C 1 ( 1 ) . a n d C l ( 2 ) , p e r p e n d i c u l a r t o t h e R u - R u b o n d , w h i c h a p p r o x i m a t e l y t r a n s f o r m s P ( 1 ) t o P ( 2 ) a n d P ( 3 ) t o P ( 4 ) . T h e c r y s t a l l o g r a p h i c a l l y u n s e e n h y d r i d e s m u s t b e a s y m m e t r i c a l l y d i s p o s e d t o a c c o u n t f o r t h i s d i s p a r i t y . T h e u n o b s e r v e d J T T T J a n d nn \u2022 J p g ^ c j _ s ^ c o u p l i n g s i n d i c a t e t h e y a r e q u i t e s m a l l , a l t h o u g h t h i s i s n o t u n u s u a l w i t h p o l y h y d r i d e c o m p l e x e s 1 3 1 . T o r a t i o n a l i z e - t h e a v a i l a b l e d a t a , t h e f o l i o w l n g . - . v p o s l t l o n i n g o f t h e - U 2 -h y d r i d ' e s 55 and -60\u00b0C (Table V I - 6 ) . A s t e r i s k s i n d i c a t e resonances due to r e s i d u a l RuCKC-gCC^) ( P P h ^ (see t e x t ) . - 2 9 0 -T A B L E VI-6. P ' { ' H } - N . m . r ; . p a r a m e t e r s f o r t h e c o m p l e x e s w i t h t h e a p p a r e n t s t o i c h i o m e t r y R u 2 C l 3 ( 0 2 C R ) ( P P h ^ ) ^ o b s e r v e d i n t h e s t u d i e s o f t h e h y d r o g e n a t i o n o f R u C l ( . 0 o C R ) - ( P P h J o i n t o l u e n e - d o a R , t e m p e r a t u r e P A , ppm P B , ppm J A B , H z P e , ppm P D . , ppm J C D ' C \/ H r > \u20144-0 G o 5 54.8 50.7 37.5 54-5 50.35 41.5 -60\u00b0C 54.9 50.8 5 37.0 54.8 50.3 42.6 p - C , H . 0 C H _ . , -40\u00b0 6 4 3 55.0 50.4 37.15 53.9 50.5 41 .8 -60\u00b0 55.15 50.5 37.7 54.2 50.56 43.1 p - C ^ F , -40\u00b0C 54.7 50,8 37.6 53.5 50.5? 40.3 a; A t 40.505 M H z ; s e e F i g u r e 6.16. p h o s p h i n e s - p e r ' - r u t h e n i u m : . . c e n t e r - . S i n c e t h e c o m p l e x w a s m o s t r e a d i l y g e n e r a t e d , w h e n t h e t o t a l c h l o r i d e : c a r b o x y l a t e : r u t h e n i u m r a t i o w a s 3 : 1 : 2 ( o f . F i g u r e 6 . 1 3 ) . , i t I s v e r y l i k e l y t h a t t h e c o m p o u n d r e s p o n s i b l e i s R u 2 C l . j ( 0 2 C R ) (PPh^) , .^ . , w i t h s t r u c t u r e ( V l ) b e i n g t h e m o s t r e a s o n a b l e . U n f o r t u n a t e l y , t h e n a r r o w r a n g e o f c h e m i c a l s h i f t s o b s e r v e d P P h , \\\\C1\/\/t \\ C 1 H u ^ . R u 0^1 ^ \u00bb C 1 ^ I ' ^ P P h ( V I ) 3 . 0 P P h 3 \/ - 2 9 1 -f o r t h e s e c o m p o u n d s make a c c u r a t e r e s o n a n c e a s s i g n m e n t s i m p o s s i b l e . R e t u r n i n g t o t h e m a i n t h e m e , a s t h e r e s o n a n c e s o f H R u C l C P P h ^ ) ^ b e c a m e v i s i b l e , t h e r e s o n a n c e s d u e t o H R u ( 0 o C C , H , , ) ( P P h 0 ) n b r o a d e n e d 2 0 5 5 5 a n d i n some c a s e s b e c a m e d i s t o r t e d , t h o u g h t h e o t h e r r e s o n a n c e s r e m a i n e d s h a r p . T h i s d i s t o r t i o n w a s o b s e r v e d i n s e v e r a l s a m p l e s , b o t h a t - 2 0 \u00b0 a n d - 4 0 \u00b0 C . I n some c a s e s ( F i g u r e 6 . 1 5 b ) , t h e s e t o o k t h e a p p e a r a n c e o f a s e c o n d s e t o f r e s o n a n c e s c o i n c i d e n t w i t h , b u t s l i g h t l y o f f s e t ( u p t o 17 H z ) f r o m , t h e o r i g i n a l t r i p l e t a n d d o u b l e t . s i g n a l s , i n d i c a t i n g 31 a s e c o n d s p e c i e s w i t h s i m i l a r P p a r a m e t e r s . . T h i s i n i t i a l l y s u g g e s t e d a c o m p l e x o f t h e f o r m H R u t O g C C ^ H ^ ) ( P P h ^ ) y ( C ^ H ^ C O O H ) , c o n t a i n i n g a h y d r o g e n b o u n d a c i d g r o u p (cf . . . s e c t i o n 2 . 1 . 4 . 2 7 ) , s i n c e t h e t i m e f r a m e i n w h i c h t h e d i s t o r t i o n s a r o s e a p p e a r e d t o c o i n c i d e w i t h t h e p r o d u c t i o n o f H R u C l ( P P h 3 ) ^ , a n d s o b e n z o i c a c i d . A l s o , s u c h a ; 31 1 s p e c i e s w a s e x p e c t e d t o h a v e P { H}- ?n , .m . . r . p a r a m e t e r s v e r y s i m i l a r t o t h a t f o u n d f o r t h e a c i d f r e e s p e c i e s . H o w e v e r , b y s e l e c t i v e l y d e c o u p l i n g o n l y t h e p h e n y l - ' p r o t o n - r e s o n a n c e s , t h e s e d i s t o r t i o n s v a n i s h e d ( F i g u r e 6 . 1 5 c ) a n d t h e r e s u l t i n g q u a r t e t a n d t r i p l e t r e s o n a n c e s w e r e i n d i s t i n g u i s h a b l e f r o m t h o s e o b s e r v e d i n s p e c t r a o f p u r e \u2022 . . H R u ( 0 \u201e C C , H r ) ( P P h 0 ) 0 o b t a i n e d u n d e r i d e n t i c a l c o n d i t i o n s . T h i s 2 o ;> 5 5 i n d i c a t e d t h e p r e s e n c e o f o n l y o n e s p e c i e s - H R u ^ g C C ^ H ^ . ) ( P P h ^ ) y T h i s a n o m a l o u s b e h a v i o r .was p r o b a b l y c a u s e d b y u n r e c o g n i z e d o r u n d e t e c t e d v a r i a t i o n s i n t h e l e v e l o f t h e d e c o u p l i n g p o w e r . T h e s p e c t r u m s h o w n i n F i g u r e 6 . 1 5 b ' w a s o b t a i n e d w i t h a h e t e r o h i g h d e c o u p l e r s e t t i n g o f 50 d B a n d a 2 0 0 0 H z b a n d w i d t h ( s e e a l s o S e c t i o n 2 . 3 ) . A l t h o u g h t h e h y d r i d e r e s o n a n c e o f t h i s s p e c i e s a t - 1 7 . 8 5 6 i s a p p r o x i m a t e l y 1 7 0 0 H z u p f i e l d f r o m t h e c e n t e r o f t h e b r o a d b a n d d e c o u p l i n g f r e q u e n c y i n t o l u e n e - d g , s u c h a s e t t i n g n o r m a l l y p r o v i d e d s u f f i c i e n t p o w e r t o c o m p l e t e l y d e c o u p l e a l l o f t h e p r o t o n s i n - 2 9 2 -H R u ( 0 2 C C 6 H 5 ) ( P P h 3 ) 3 i n c l u d i n g t h e h y d r i d e r e s o n a n c e . I f t h e d e c o u p l e r p o w e r f e l l t o a l e v e l j u s t b e l o w t h a t r e q u i r e d t o c o m p l e t e l y 31 1' d e c o u p l e t h e h y d r i d e , t r i e \u2022 r e s u l t i n g ? { il} - n . m . r s p e c t r a w o u l d s h o w t h e e f f e c t s o f \" s p i n t i c k l i n g \" 1 8 5 - 1 8 7 ; t h a t i s , t h e p h o s p h o r u s r e s o n a n c e s o r d i n a r i l y c o u p l e d t o t h e h y d r i d e w o u l d s h o w a d d i t i o n a l s p l i t t i n g , a n d , \u2022 t h e ' . - . s p e c t r a \" o b t a i n e d , - w o u l d . . . ' . h a v e t h e a p p e a r a n c e o f t h a t o f F i g u r e 6 . 1 5 b . I t i s n o t c l e a r w h y s u c h a p o w e r r e d u c t i o n o c c u r r e d o n l y d u r i n g t h e i n t e r m e d i a t e s t a g e s o f t h e r e a c t i o n . . One p o s s i b l e e x p l a n a t i o n i n v o l v e s t h e o p e r a t i n g t i m e s i n v o l v e d . T h e i n t e r m e d i a t e s t a g e s o f t h e s e r e a c t i o n s w e r e m o n i t o r e d a f t e r t h e i n s t r u m e n t h a d b e e n o p e r a t i n g f o r s e v e r a l h o u r s ; t h e h e a t g e n e r a t e d b y t h e d e c o u p l i n g c h a n n e l may h a v e b e e n s u f f i c i e n t t o c a u s e p r o b l e m s w i t h t h e e l e c t r o n i c s . A g a i n r e t u r n i n g t o t h e h y d r o g e n r e a c t i o n , l o n g e r t i m e s (24-h) g a v e f o r m a t i o n o f m a i n l y H R u C l ( P P h J 0 w i t h some r e s i d u a l H R u ( 0 o C C , H _ ) ( P P h J _*> 5 2 o 5 3 3 t h o u g h t h e p o o r s o l u b i l i t y o f t h e f o r m e r s p e c i e s t e n d e d t o c a u s e i t t o p r e c i p i t a t e f r o m s o l u t i o n . P e r t i n e n t t o t h e c h a r a c t e r i z a t i o n o f H R u C l ( P P h 3 ) 3 i n t o l u e n e s o l u t i o n , , t h e p a r a m e t e r s o f t w o o t h e r s p e c i e s w e r e a l s o i n v e s t i g a t e d . T h e c o m p l e x H R u C l ( P t o l 3 ) 3 w a s p r e p a r e d b y r e a c t i n g [ H g R u C l C P t o l ^ w i t h e x c e s s P t o l 3 i n b e n z e n e ( S e c t i o n 2 . 1 . 4 . 1 6 . ) . T h i s s o l v a t e - f r e e 31 1 c o m p l e x i n t o l u e n e - d g h a d P { H } - n . m . r . p a r a m e t e r s o v e r t h e t e m p e r a t u r e r a n g e +60 t o - 7 0 \u00b0 C e s s e n t i a l l y i d e n t i c a l t o t h o s e d e s c r i b e d p r e v i o u s l y f o r H R u C l ( P P h 3 ) . 3 ( t o l u e n e ) i n C D g C l g 6 8 . T h e p o s i t i o n o f t h e h y d r i d e r e s o n a n c e f o r t h e P t o l a n a l o g u e ( a t 2 5 \u00b0 G : 1 : 3 : 3 : 1 q u a r t e t , = 3 r n 2 6 H z ) s h o w e d . a s l i g h t s o l v e n t d e p e n d e n c e , a p p e a r i n g a t - 1 6 .846 a n d - 1 7 . 7 8 6 i n C ^ D ^ . a n d C D C l . ^ , . r e s p e c t i v e l y . L e v i s o n a n d R o b i n s o n 3 8 h a v e r e p o r t e d a . s e c o n d c o m p l e x , f o r m u l a t e d a s H Q R u ( P P h , ) Q , w h i c h i s - 2 9 3 -r e p o r t e d t o e x h i b i t a q u a r t e t h y d r i d e r e s o n a n c e a t - 1 7 . 2 5 ( J D U = 28 H z ) T n G g D . ^ . ; , , i 'e.:.,: i n t h e same r e g i o n a s t h a t r e p o r t e d f o r H R u C l C P P h ^ ) . j . On r e p e a t i n g t h e i r s y n t h e s i s . , o n l y H ^ R u C C O ) ( P P h ^ ) ^ w a s o b t a i n e d i n h i g h y i e l d , w i t h n o e v i d e n c e f o r a n y h y d r i d e a t - 1 7 . 2 6 ( S e c t i o n 2 . 1 . 4 . 2 3 ) . T h e r e w a s n o e v i d e n c e f o r t h e f o r m a t i o n o f [ H ^ R u C l t P P h ^ ) 2 ] 2 i n a n y n ^ m . r . s p e c t r u m , o b t a i n e d d u r i n g s t u d i e s o n t h e c h l o r o c a r b o x y l a t o -t r i s ( p h o s p h i n e ) s y s t e m s . 6 . 5 . 3 . D i s c u s s i o n ' ' ' o f t h e h y d r o g e n a t i o n r e a c t i o n s . O f t h e t w o c h l o r o c a r b o x y l a t o s y s t e m s e x a m i n e d b y n . m . r . , t h e t r i s ( p h o s p h i n e ) s y s t e m . , R u C l f O ^ C ^ H ^ ) ( P P h ^ ) y w a s m o s t s t r a i g h t f o r w a r d f o r i n t e r p r e t a t i o n . H o w e v e r , i n c o n t r a s t t o t h e s i m p l i s t i c e x p e c t a t i o n s e x p r e s s e d i n e q u a t i o n . 6 , 1 8 , . c o n c e r n i n g t h e p r e f e r e n t i a l e l i m i n a t i o n o f c a r b o x y l i c a c i d , t h e p r e f e r r e d mode o f r e a c t i v i t y a p p e a r s t o b e f o r m a t i o n o f a h y d r i d e w i t h e l i m i n a t i o n , o f H C 1 , w h i c h i s t h e n c a p t u r e d b y s t a r t i n g m a t e r i a l t o f o r m R u C l ^ P P h ^ ) y D i m e r i z a t i o n o f R u C l ^ P P h . ^ ^ a n d R u C l ( 0 2 C C ^ H ^ ) ( P P h ^ ) ^ w i t h l o s s o f p h o s p h i n e i s t h o u g h t t o g i v e r i s e 31 t o t h e s p e c i e s R u \u201e C l o ( 0 o C C ^ H r ) ( P P h _ ) , o b s e r v e d i n t h e P - n . m . r . 2 3 2 o 5 3 4 s p e c t r a ( e q u a t i o n s 6 , 2 6 - 6 , 2 8 ) . . . T h e v i s i b l e s p e c t r a l c h a n g e s a t l o w e r R u C ! (DJ'C^iJiVPa^y* ' ^ 2 \/..\" % > - H R ^ C Q ^ e G ^ H ^ ) (PPh^ . ) - +\/\/HC1'' \u2022 ( 6 , 2 6 ) . . R u C l - ( 0 - G C , , H c ) ( P P h o ) _ + H C 1 . * - R u C l \u201e ( P P h _ ) _ + C . H c C 0 0 H . ( 6 . 2 7 ) 2 o 5 3 3 2 3 3 o 5 - \u2022 ' \u2022 . \u2022 R u C l ( 0 2 C C 6 H 5 ) ( P P h 3 ) 3 + R u C l 2 ( P P h 3 ) 3 \u2014 ^ - R u 2 C l 3 ( 0 2 C C 6 H 5 ) ( P P h 3 ) 3 < 6 . 2 8 ) + 2 P P h . - 2 9 4 -- \u2022 r u t h e a i u m , : C\u00ae n c e h t r a t i o n s . ( c a . 5 x 1 0 \" % ) , a s . R u C l ( 0 2 C C ^ H ^ ) ( P P h ^ ) 3 r e a c t s ' w i t h H ^ , a r e c o n s i s t e n t w i t h a m u l t i s t e p p r o c e s s i n v o l v i n g m o r e t h a n o n e s l o w s t a g e . T h e r e a s o n s f o r t h e p a t h w a y o f r e a c t i o n ' ' 6 . 2 6 i n v o l v i n g H C 1 e l i m i n a t i o n , , r a t h e r t h a n RCOOH.,, a r e n o t i m m e d i a t e l y o b v i o u s , b u t p e r h a p s t h e b i d e n t a t e mode o f c a r b o x y l a t o c o o r d i n a t i o n i n t h e p r e c u r s o r c o m p o u n d s a n d i n t h e h y d r i d e , H R u C O ^ C R ) ( . P P h ^ ) ^ , i s k i n e t i c a l l y m o r e s t a b l e t h a n i n i t i a l l y e x p e c t e d . F o r e x a m p l e , i n i t i a l f o r m a t i o n - o f H R u C O ^ C R ) ( P P h ^ ) ^ may b e p r e f e r r e d o v e r f o r m a t i o n o f H R u C l C P P h ^ ) ^ b e c a u s e o f t h e s i x - c o o r d i n a t e g e o m e t r y o f t h e f o r m e r ( s e e a l s o S e c t i o n 3 . 1 ) . I n t h e r e a c t i o n o f t h e p - s u c c i n a t o b i s ( p h o s p h i n e ] c o m p l e x w i t h H ^ , t h e c o r r e s p o n d i n g [ H R u ( 0 2 C C H 2 C H 2 C 0 0 H ) ( P P h ^ ) 2 ] n w a s n o t o b s e r v e d . T h i s , , a n d t h e f a c t t h a t b i s ( p h o s p h i n e ) c a r b o x y l a t o h y d r i d e s p e c i e s c o n t a i n i n g w e a k d o n o r l i g a n d s h a v e n o t b e e n r e p o r t e d , s u g g e s t a l e s s e r d e g r e e o f s t a b i l i z a t i o n i n t h i s t y p e o f c o m p o u n d t h a n i n t h e t r i s ( p h o s p h i n e ) s y s t e m s . I n t h e u - s u c c i n a t o . c a s e , t h e h y d r o g e n a t i o n a p p a r e n t l y p r o c e e d s a t l e a s t i n p a r t a s e x p e c t e d ( e q u a t i o n 6 . 1 8 , n = 2 ) t o g i v e R u C l ( 0 2 C C H 2 C H 2 C O O H ) ( D M A ) ( P P h 3 ) 3 a s i n e q u a t i o n 6 , 2 9 . H o w e v e r , [ R u C l(DMA0 ( P P h 3 ) 2 ( O 2 C C H 2 4 4 - 2 + ^ 2 +~ \u00bb H R u C l ( D M A ) ( P P h 3 ) 2 \" + R u C l ( 0 2 C C H 2 C H 2 C 0 0 H ) ( D M A ) ( P P h 3 ) 2 ( 6 . 2 9 ) a n o t h e r p l a u s i b l e , , b u t s p e c u l a t i v e , r o u t e t o g i v e t h e c h l o r o c a r b o x y l a t o b i s ( p h o s p h i n e ) . m o n o m e r c a n b e e n v i s a g e d . M o r e i n l i n e w i t h t h e c h e m i s t r y o b s e r v e d i n t h e t r i s ( p h o s p h i n e ) s y s t e m , t h i s r o u t e i n v o l v e s r e a c t i o n o f i n i t i a l l y l i b e r a t e d H C l . w i t h t h e s t a r t i n g m a t e r i a l , a s i n e q u a t i o n s - 6 . 3 0 - ' 6 . 3 1 . - * B y t h i s p a t h . , h o w e v e r , t h e s p e c i e s d e s i g n a t e d - 2 9 5 -[ R u C l ( D M A ) ( P P h 3 ) ^ . ( 0 2 G C H 2 ^ - 2 + H 2 \u2022 \" H R u ( 0 2 C C H 2 C H 2 C 0 0 H ) ( D M A ) ( P P h 3 ) 2 \" + H C l ( 6 . 3 0 ) [ R u C l ( D M A ) ( P P h 3 ) 2 ( 0 2 C C H 2 - H - 2 + H C l \" R u C l 2 ( D M A ) ( P P h 3 ) 2 \" + R u C l ( 0 2 C C H 2 C H 2 C 0 0 H ) ( D M A ) ( P P h 3 ) 2 ( 6 . 3 1 ) a s \" , J:Riaei ' 2 ; ( ' .DMAK'PPh 3 r ) ' 2 ' n j i f ' g e n e r a t e d . , - - w o u l d : p r o b a b l y \u2022 M i n e r i z e t o g i v e e i t h e r R u 2 C l ^ ( D M A ) ( P P h ^ ^ o r [ R u C l 2 ( P P h 3 ) 2 ] 2 \u201e N e i t h e r s p e c i e s w a s o b s e r v e d , w h i c h may t e n d t o d i s c o u n t t h i s l a t t e r r o u t e . B e c a u s e o f t h e c o m p l e x i t y o f t h i s b i s ( p h o s p h i n e ) s y s t e m , t h e a b s e n c e o f a r e p r o d u c i b l y w e l l - d e f i n e d A B C D p a t t e r n d o e s l i t t l e t o e i t h e r s u p p o r t o r r e f u t e i t s p r e s u p p o s e d f o r m u l a t i o n a s [ H R u C l ( P P h 3 ) 2 ] , F o r t h e same r e a s o n s , t h o u g h , i t s p o s s i b l e d e t e c t i o n d o e s n o t c o n f l i c t w i t h t h e f o r m u l a t i o n H _ R u _ C l _ ( P P h _ ) . p u t f o r w a r d i n C h a p t e r 5 , s i n c e 3 <\u2022 5 5 4 l i g a n d - - s c r a m b l i n g -;by d i s p r o p o r t i o n a t i o n ' c o u l d \" a l s o ' a c c o u n t f o r t h i s s p e c i e s ' e x i s t e n c e i n t h e c a r b o x y l a t o s y s t e m . . I n a n y c a s e , t h e c o n c e n t r a t i o n n e v e r d e v e l o p e d i n s u f f i c i e n t l y h i g h l e v e l s t o b e o f u s e 1 m H n . m . r . s t u d i e s , a n d t h e s y s t e m w a s n o t e x a m i n e d f u r t h e r . 6 . 6 . D i s c u s s i o n o f t h e i d e n t i t y , a n d r e a c t i v i t y w i t h h y d r o g e n , o f t h e H R u C l ( P P h 3 ) 3 c o m p l e x i n b e n z e n e o r t o l u e n e . T o w a r n i c k y a n d S c h r a m 1 8 8 \u00bb 1 8 9 h a v e r e c e n t l y i s o l a t e d a c o m p l e x f r o m t h e r e a c t i o n b e t w e e n H 0 R u ( P P h 0 ) . a n d C l 0 S i . P h 0 w i t h N E t \u201e i n b e n z e n e <\u2022 3 4 2 4 0 5 w i t h a n e m p i r i c a l f o r m u l a H R u C l ( P P h 3 ) 3 \u00bb H o w e v e r , t h e s e a u t h o r s c o n s i d e r t h e r e s u l t i n g r u t h e n i u m c o m p l e x t o b e d i m e r i c , p a r t l y b a s e d o n -296-a n a l y t i c a l and molecular weight data (osmometry i n CHCl^ gave a value of 1600 g\/mol compared w i t h I 8 4 8 g\/mol c a l c u l a t e d f o r the dimer; the molecular weight decreased w i t h t i m e ) , p a r t l y on i t s decomposition i n benzene or THF w i t h l o s s of H^, but a l s o more im p o r t a n t l y on the f a c t t h a t t h e i r complex was s o l u b l e and gave n.m.r. spectra i n C^D^, whereas the more f a m i l i a r monomeric HRuCl^Ph^)^ s o l v a t e ( s o l v a t e = benzene or toluene) does not. The\"1 d i f f e r e n c e s . i n quoted; s o l u t i o n -spectroscopic p r o p e r t i e s (Table VI-7), however, do not a c t u a l l y d i f f e r e n t i a t e the TABLE VI-7 Reported p r o p e r t i e s f o r the Schram dimer, [ H R u C l ( P P h 3 ) ^ ] 2 & and Wilkinson's product, HRuCl(PPhJ -C,H,b. Property M e l t i n g p o i n t V R u - H ^ u J 1 -1 (N jol)-, cm\" H n.m.r. resonances phenyl hydride 3 1P{ 1H}-n,m.r. s h i f t Dimer 168\u00b0C 2030 7.5, 6.96 -17.46 (q, 26 Hz) 56.9 ppm Monomer 218-220\u00b0C 2020 7.16\" - 1 7 . 4 6 % , 26 Hz) -18.16 S(q, 26 Hz) 59.0 ppm e , f Reference 188 Reference 27. In C 6D 6. (d) In CDC1 3. (e) In CD 2C1 2. ( f ) Reference 68. - 2 9 7 -18 8 two compounds, and r e s u l t , i n f a c t , only from the acknowledged poor s o l u b i l i t y of the solvated monomers i n C^D^ or t o l u e n e - d g 2 7 . The dimer species was a l s o too i n s o l u b l e i n toluene-dg f o r low temperature n.m.r. s t u d i e s , but the authors \u2022 consideredv'it--to-be-a_j\"bis-u-\"chloro bridged species w i t h Ru i n a pseudo octahedral environment and w i t h PPh^ exchange t a k i n g place\" I n the present study, a complex was generated i n the t r i s 1 31 1 (phosphine) ch l o r o c a r b o x y l a t o system which had H and P{ H}-n.m.r. parameters e s s e n t i a l l y i d e n t i c a l w i t h those'\" reported'-'by Towarnicky and Schram f o r t h e i r dimer (see a l s o S e c t i o n 7.3.1). At 25\u00b0C i n C^D^, the H n.m.r. spectrum-showed a -hydride resonance at -17.56 (q, 26Hz) th a t broadened under Hg - a r e a c t i o n p r e v i o u s l y described f o r HRuCl(PPh 3)^ i n CDCl^ 1 8 1* (see a l s o below). The \"^P{''H}-n.m.r. spectrum showed a broad s i n g l e t a t 58 + 1 ppm which s p l i t to a doublet on s e l e c t i v e phenyl proton decoupling. The same species was a l s o generated i n toluene-dg. On lowering the temperature i n t h i s s o l v e n t , the generated complex showed the s i t e exchange c h a r a c t e r i s t i c s reported f o r HRuCltPPh^)^ i n CDgClg 6 8; at -60\u00b0C, the broad s i n g l e t was replaced by unresolved s i g n a l s at 95 and 39.5 ppm ( r e l a t i v e i n t e n s i t i e s 1 : 2) compared with Caulton's low temperature (-74\u00b0C) values of 94--0 ( t ) and 38.4 ppm (d, 28 H z ) 6 8 . There i s l i t t l e doubt t h a t the species generated i n the present work, at l e a s t , was the f a m i l i a r monomeric species HRuCltPPh^)y The.sharpness of the hydride'resonance of Towarnicky's and Schram's compound (reference\"188, Figure 2) i n d i c a t e s t h a t there i s l i t t l e d i s s o c i a t i o n which could l e a d to exchange broadening. In view of the s t e r i c c o n s t r a i n t s of P P h ^ 6 7 , i t i s u n l i k e l y t h a t s i x such l i g a n d s could coordinate around a dimeric ruthenium system bridged by chloro (or hydrido) l i g a n d s as suggested. No such arrangement i s known i n - 2 9 8 -p l a t i n u m m e t a l c h e m i s t r y a n d i t s e e m s m o r e l i k e l y t h a t t h e c o m p o u n d i s o l a t e d b y T o w a r n i c k y a n d S c h r a m w a s t h e s o l v a t e - f r e e m o n o m e r . H R u C l ( P P h 3 ) 3 . T h e r e a c t i o n o f H R u C l ( P P h 3 ) 3 w i t h E^\/D^ h a s b e e n s t u d i e d p r e v i o u s l y b y S t r a t h d e e a n d G i v e n 1 8 1 * . T h e s e a u t h o r s f o u n d t h a t t h i s h y d r i d o c o m p l e x w a s a n e x t r e m e l y e f f i c i e n t c a t a l y s t f o r r e a c t i o n 6 . 3 2 , s o m u c h H 2 + D 2 ;^=S= 2 HD ( 6 . 3 2 ) s o t h a t t h e p r o b l e m s o f i n t e r f a c i a l m a s s t r a n s p o r t o f c o u l d n o t b e e l i m i n a t e d . T h e y a l s o r e p o r t e d t h a t t h e h y d r i d e r e s o n a n c e o f H R u C l ( P P h 3 ) 3 b r o a d e n e d u n d e r H 2 o r D^, b u t t h a t t h e r a t e o f e x c h a n g e o f t h e R u - H b o n d w i t h D 2 w a s i n s i g n i g i c a n t w i t h r e s p e c t t o t h e H 2 ~ D 2 e q u i l i b r a t i o n p r o c e s s . M o r e r e c e n t l y , S t o l z e n b e r g a n d M u e t t e r t i e s a l s o r e p o r t e d t h e same h i g h - f i e l d H l i n e b r o a d e n i n g o f H R u C l ( P P h 3 ) 3 u n d e r E^, a n d e s t i m a t e d t h a t t h e e x c h a n g e p r o c e s s r e s p o n s i b l e i s m u c h m o r e r a p i d ( k ^ 2 0 s ) t h a n t h e p h o s p h i n e d i s s o c i a t i o n u n d e r a r g o n ( k ^ ^ 0 . 5 s f o r e q u a t i o n 6 . 3 3 ) 1 1 * 5 . b u t o f f e r e d n o e x p l a n a t i o n a s t o H R u C l ( P P h ) \u201e H R u C l ( P P h ) + P P h ( 6 . 3 3 ) k _ 1 t h e n a t u r e o f t h e e x c h a n g e p r o c e s s o b s e r v e d u n d e r h y d r o g e n . T o a c c o u n t f o r t h e i r o b s e r v e d r a t e l a w ( - d . [ D 2 ] \/ d t = k [ D 2 ]^ ' ^ '[RU]^'3^ [ P P h 3 ] G ) a n d t h e s e o b s e r v a t i o n s , S t r a t h d e e a n d G i v e n p r o p o s e d t h e m e c h a n i s m o f e q u a t i o n s 6 . 3 4 - 6 . 3 6 , w i t h k ^ a s t h e r a t e l i m i t i n g s t e p . S u c h a m e c h a n i s m d o e s e x p l a i n ' t h e o b s e r v e d r a t e d a t a , R u H C l ( P P h 3 ) 3 + D 2 4 D 2 R u ( P P h 3 ) 3 + H C 1 (6.34) ^-4 \u2022299-k:5 D 2 R u ( P P h 3 ) 3 + g 2 ^ H 2 D 2 R u ( P P h 3 ) 3 (6.35) k-5 k ' H D R u ( P P h ) , \u201e \" 5 ^ H D R u ( P P h ) + HD (6.36) 5 a f t e r t a k i n g t h e p h y s i c a l p r o c e s s e s i n t o a c c o u n t 1 9 0 , b u t s e v e r a l p r o b l e m s r e m a i n . F i r s t , t h e k s t e p p r o b a b l y p r o c e e d s b y w a y o f a R u ( l V ) i n t e r -4 m e d i a t e , R u D 2 H C l ( P P h 3 ) y v e r y s i m i l a r t o t h e p r o p o s e d R u H 2 D 2 ( P P h 3 ) 3 > a n d i t i s d i f f i c u l t t o u n d e r s t a n d w h y R u - H \/ D 2 e x c h a n g e w o u l d n o t o c c u r i n t h e f o r m e r c a s e . S e c o n d , a n d p e r h a p s m o r e i m p o r t a n t , t h e p r o p o s e d a c t i v e c e n t e r , R u H D ( P P h Q ) Q , . g e n e r a t e d i n s i t u f r o m H R u ( P P h . , ) . , w a s n 4~n 3 5 <\u2022 i 4 f o u n d t o b e l e s s t h a n 10$ a s r e a c t i v e f o r c a t a l y z i n g t h e reactionc6.32 a s t h e m o n o h y d r i d e . A n i n d e p e n d e n c e o f t h e e x c h a n g e r a t e o n a d d e d P P h 3 l e d S t r a t h d e e a n d G i v e n i n . o n e s e c t i o n o f t h e p a p e r t o c o n c l u d e t h a t \" g e n e r a t i o n o f t h e c a t a l y t i c a l l y a c t i v e s p e c i e s d i d n o t r e q u i r e d i s s o c i a t i o n o f P P h 3 f r o m t h e c o m p l e x \" 1 8 4 ; a n d y e t t h e s u g g e s t e d a c t i v e t r i s p h o s p h i n e p r e c u r s o r H 2 R u ( P P h 3 ) 3 i s l a t e r c o n s i d e r e d t o r e a d i l y f o r m i n t h e p r e s e n c e - o f p h o s p h i n e t h e i n a c t i v e t e t r a k i s p h o s p h i n e s p e c i e s , H _ R u ( P P h Q ) . . I n a n y e v e n t , i n v i e w o f t h e f a c t t h a t t h e 2 3 4 r e a c t i o n r a t e s a p p e a r t o b e l a r g e l y d i f f u s i o n c o n t r o l l e d ( \" a r e d u c t i o n i n a g i t a t i o n r a t e b y a f a c t o r o f t w o d e c r e a s e d t h e r e a c t i o n r a t e b y a f a c t o r o f a p p r o x i m a t e l y t w o i ' ) . , t h e i n d e p e n d e n c e o f r a t e o n p h o s p h i n e c o n c e n t r a t i o n c a n b e o f l i t t l e v a l u e i n d e f i n i n g t h e c a t a l y t i c s p e c i e s . T h e s e a u t h o r s n o t e d a s m a l l b u t s i g n i f i c a n t a b s o r p t i o n o f H 2 b y b e n z e n e s o l u t i o n s o f H R u C l ( P P h 3 ) 3 ( H 2 : R u ~ .0.06) a n d i m p l i e d f o r m a t i o n o f H 2 R u ( P P h 3 ) v i a r e a c t i o n 6.34-. I n t h e p r e s e n t w o r k , o n e x a m i n i n g t h e c o r r e s p o n d i n g P t o l 3 a n a l o g u e , H R u C l ( P t o l 3 ) | , i n t o l u e n e - d g ( [ R u ] T - 9 X l O - 2 ^ ) , t h e a d d i t i o n o f H 2 c a u s e d t h e same - 3 0 0 -t e m p e r a t u r e - d e p e n d e n t s i g n a l b r o a d e n i n g a s w a s o b s e r v e d ( F i g u r e 6 . 1 7 ) . T h i s c o r r e s p o n d s t o t h e p o s i t i o n o f t h e h y d r i d e r e s o n a n c e o f [ H ^ R u C ^ P t o l ^ ) ] 2 i n t h i s s o l v e n t a n d i s --.at l e a s t q u a l i t a t i v e l y c o n s i s t e n t w i t h t h e v i s i b l e s p e c t r o p h o t o m e t r i c c h a n g e s s h o w n i n F i g u r e 6 . 1 1 . T h e r e s o n a n c e a t - 1 2 . 8 6 w a s n o t p r e s e n t b e f o r e t h e a d d i t i o n o f H ^ , w h e n v i e w e d a t t h e . s a m e s c a l e e x p a n s i o n , w h i c h d i s c o u n t s t h e p o s s i b i l i t y t h a t i t w a s d u e t o r e s i d u a l [ H 2 R u C l ( P t o l 3 ) 2 ] 2 f r o m t h e p r e p a r a t i o n o f t h e t r i s ( p h o s p h i n e ) c o m p l e x ( S e c t i o n 2 . 1 . 4 . 1 6 ) . 31 1 H o w e v e r , u n d e r i d e n t i c a l c o n d i t i o n s , n o e v i d e n c e w a s f o u n d b y P { H } -n . m . r . f o r t h e b i s ( p h o s p h i n e ) s p e c i e s , f r e e P t o l ^ , o r p h o s p h i n e o x i d e . T h e e q u i l i b r i u m c o n s i d e r e d p r e v i o u s l y a n d g i v e n i n e q u a t i o n 6 . 3 7 w i l l 2 H R u C l ( P t o l 3 ) 3 + H 2 H 2 R u C l ( P t o l 3 ) 2 2 + 2 P t o l ( 6 . 3 7 ) n e c e s s a r i l y d e p e n d o n t h e t o t a l r u t h e n i u m c o n c e n t r a t i o n a t f i x e d [ H g ] . A l t h o u g h e q u a t i o n 6 . 3 7 may a c c o u n t f o r t h e p r e s e n c e o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 a t l o w e r r u t h e n i u m c o n c n e t r a t i o n s ( F i g u r e 6 . 1 1 ) , t h e a b s e n c e o f a n y s i g n i f i c a n t h y d r o g e n u p t a k e a t [ R u ] ^ = 3 x 10 ^ M t e n d s , t o p r e d i c t a m u c h l o w e r a m o u n t o f [ H 2 R u C l ( P t o l 3 ) 2 ] 2 t h a n w a s o b s e r v e d i n t h e H -n . m . r . s t u d i e s , I t i s n o t k n o w n w h e t h e r [ H 2 R u C l ( P P ] J 3 ) 2 ] 2 i s t h e a c t i v e H 2 ~ D 2 e x c h a n g e c a t a l y s t , o r s i m p l y a s i d e - r e a c t i o n p r o d u c t . H o w e v e r , i t i s n o t e d h e r e t h a t t h e h y d r i d e l i n e b r o a d e n i n g o b s e r v e d c o u l d e q u a l l y b e c a u s e d b y ^ - c a t a l y z e d p h o s p h i n e e x c h a n g e ( e q u a t i o n 6 . 3 3 ) s o t h e a c t i v e c a t a l y s t may b e a b i s ( p h o s p h i n e ) s p e c i e s . - 3 0 1 -a - e . S p e c t r u m ( e ) o b t a i n e d a f t e r r e m o v i n g H - 3 0 2 -CHAPTER 7 . CHARACTERIZATION AND REACTIONS OF CHLOROHYDRIDO(NORBORNADIENE)- B I S ( T R I P H E N Y L P H O S P H I N E ) R U T H E N I U M ( I I ) . 7 . 1 I n t r o d u c t i o n . T r a n s i t i o n m e t a l c o m p l e x e s c o n t a i n i n g o l e f i n , d i o l e f i n , o r a l l y l l i g a n d s a r e b e c o m i n g i n c r e a s i n g l y p o p u l a r a s p r e c u r s o r s f o r s t u d i e s i n c a t a l y t i c r e a c t i o n s , p a r t i c u l a r l y f o r h y d r o g e n a t i o n . F o r e x a m p l e , s e v e r a l g r o u p s 1 9 4 ~ 1 3 5 h a v e - r e c e n t l y ; ' - u s e d d i e n e p r e c u r s o r s t o g e n e r a t e [ R h ( P P ) ( s o l v e n t ) ^] [ B F ^ ] (~P~~V = d i p h o s , c h i r a p h o s ) c o m p l e x e s a n d e l u c i d a t e d m e c h a n i s t i c d e t a i l s o f t h e a s y m m e t r i c h y d r o g e n a t i o n o f p r o c h i r a l o l e f i n s b y n . m . r . I n p a r t i c u l a r , t h e c o o r d i n a t i o n r e q u i r e m e n t s a n d a v a i l a b l e o x i d a t i o n s t a t e s o f r h o d i u m , i r i d i u m , a n d p l a t i n u m b a s e d o n d ^ a n d d^ 1 c o n f i g u r a t i o n s make s t u d i e s w i t h t h e s e m e t a l s e s p e c i a l l y c l e a n a n d a t t r a c t i v e . I n c o n t r a s t , t h e c o r r e s p o n d i n g c h e m i s t r y o f r u t h e n i u m i s m u c h l e s s d e v e l o p e d . A l t h o u g h t h e r e i s c o n s i d e r a b l e c h e m i s t r y i n v o l v i n g s y n t h e s i s a n d s u b s t i t u t i o n r e a c t i o n s o f d i e n e p r e c u r s o r s 2 7 ' 1 9 s ~ 1 9 9 , f e w e x a m p l e s e x i s t i n w h i c h t h e s e l i g a n d s a r e r e m o v e d b y h y d r o g e n a t i o n t o p r o d u c e c o o r d i n a t i v e l y u n s a t u r a t e d m e t a l c e n t e r s . I n a n e f f o r t t o f u r t h e r u n d e r s t a n d t h e i n t e r m e d i a t e s i n v o l v e d w i t h t h e b i s ( p h o s p h i n e ) . . r u t h e n i u m s y s t e m , - t h e c h e m i s t r y , o f H R u C l ( n b d ) ( P P h ^ ) p 2 7 w a s e x p l o r e d . A l t h o u g h t h i s c o m p o u n d i s f r e q u e n t l y - 3 0 3 -1 3 c i t e d a s a r a r e e x a m p l e o f a h y d r i d o - o l e f i n c o m p o u n d ' , l i t t l e i s k n o w n o f i t s c h e m i s t r y . U n d e r c o n d i t i o n s o f h y d r o g e n a t i o n , t h i s c o m p o u n d h a s t h e p o t e n t i a l t o g e n e r a t e a r e l a t i v e l y \" n a k e d \" r u t h e n i u m c e n t e r ( s ) . I n n o n - c o o r d i n a t i n g s o l v e n t s , s u c h a s b e n z e n e o r t o l u e n e , t h i s w o u l d f a c i l i t a t e p r o d u c t i o n . o f p o l y n u c l e a r f r a g m e n t s , s u c h a s t h a t w h i c h -has- b e e n ' - . i d e n t i f i e d ' ' t e n t a t i v e l y a s , [ H R u G l * ( P P h ^ ) 2 ] n \u2022 I t w a s o f p a r t i c u l a r - i n t e r e s t t o d e t e r m i n e i f t h i s h y ' d r i d o c o m p l e x c o u l d b e p r o d u c e d b y \" s u c h ? . a p r o c e d u r e . 7 . 2 P r e p a r a t i o n a n d c h a r a c t e r i z a t i o n . T h e c o m p l e x w a s p r e p a r e d a c c o r d i n g t o t h e p r o c e d u r e o f W i l k i n s o n a n d c o - w o r k e r s 2 7 b y t h e i n t e r a c t i o n o f n o r b o r n a d i e n e w i t h H R u C l C P P h ^ ) ^ \u2022 ' 31 1 ( S e c t i o n 2 . 1 , 4 v l 4 . ) , P { H } - N . m . r . i n v e s t i g a t i o n s o f t h e r e a c t i o n m i x t u r e i n d i c a t e t h a t t h e r e a c t i o n i s c l e a n , a n d t h a t n o o t h e r p h o s p h o r u s - c o n t a i n i n g p r o d u c t s a r e f o r m e d , , d e s p i t e t h e l o w i s o l a t e d y i e l d ( c a . 50%).. I n c o n t r a s t t o t h e i m p l i e d , r e p o r t e d i s o l a t i o n p r o c e d u r e , h o w e v e r , i t w a s n e c e s s a r y t o s t i r t h e r e a c t i o n m i x t u r e w i t h p e t r o l e u m e t h e r f o r s e v e r a l h o u r s t o o b t a i n t h i s y i e l d . A t t e m p t s t o i m p r o v e t h i s y i e l d b y r e d u c i n g t h e s o l u t i o n v o l u m e p r i o r t o a d d i t i o n o f p e t r o l e u m e t h e r , o r b y s c a l i n g u p t h e r e a c t i o n , g a v e p r o d u c t s o f i n f e r i o r q u a l i t y . T h e i n f r a r e d s p e c t r u m ( K B r p e l l e t ) o f t h e i s o l a t e d s o l i d s h o w e d -1 a s i n g l e - v n T T a t 2 0 7 5 cm . E x c e p t , f o r some vn \u201e b a n d s b e l o w 3 0 0 0 R u - n O - n -1 cm , t h e s p e c t r u m w a s i d e n t i c a l w i t h t h a t o f t h e s t a r t i n g m a t e r i a l , H R u C l f P P h ^ ) ^ . t o l u e n e ; b a n d s o f c o o r d i n a t e d n o r b o r n a d i e n e 2 0 0 w e r e n o t d i s c e r n a b l e . T h e ^ ' P { ' H } - n . m . r . s p e c t r u m o f t h e c o m p l e x i n C . D , t o l u e n e - d Q , 6 6 o C D ^ C N . , o r D M A : t o l u e n e - d g ( v \/ v = 1 : 1 ) c o n s i s t e d o n l y o f a s i n g l e t a t 4O.6 ppm f r o m +30\u00b0 t o -60\u00b0C, S e l e c t i v e d e c o u p l i n g o f t h e p h e n y l 2 p r o t o n s i n d i c a t e d c o u p l i n g t o a s i n g l e h y d r i d e ( d , = 24 H z ; c f . 2 1 J = 24 H z , m e a s u r e d f r o m t h e H - n . m . r . s p e c t r u m ) . rn 1 T h e H - n . m . r . s p e c t r u m i s s h o w n i n F i g u r e 7 . 1 . T h e n u m b e r a n d p o s i t i o n s o f t h e n o r b o r n a d i e n e r e s o n a n c e s c o r r e s p o n d w e l l w i t h t h e r e p o r t e d v a l u e s . . A t t e m p t s t o s e l e c t i v e l y d e c o u p l e ( a t 4OO M H z ) t h e b r o a d r e s o n a n c e s b e t w e e n 3 a n d 46 f r o m e a c h o t h e r w e r e u n s u c c e s s f u l b e c a u s e t h e s h i f t s w e r e n o t s u f f i c i e n t l y f a r a p a r t t o p r e v e n t l e a k a g e o f d e c o u p l i n g p o w e r b e t w e e n s i g n a l s . H o w e v e r , i r r a d i a t i o n o f t h e p h o s p h o r u s n u c l e i (4O,506 M H z ) . , a s e v i d e n c e d b y t h e c o l l a p s e o f t h e h y d r i d e r e s o n a n c e a t -8.886 t o a s i n g l e t , c a u s e d t h e c e n t r a l l i g a n d p e a k s t o t a k e o n t h e a p p e a r a n c e o f t r i p l e t s , w h i l e t h e o u t e r t w o r e s o n a n c e s r e m a i n e d u n c h a n g e d ( F i g u r e 7 . 1 , i n s e t ) . T h i s a l l o w s a s s i g n m e n t o f t h e p e a k s a t 3.45 a n d 3.636 a s t h e o l e f i n i c p r o t o n r e s o n a n c e s , a n d t h e o u t e r t w o s i g n a l s (3.20 a n d 3.936) a s t h e b r i d g e -h e a d p r o t o n s . 7 . 3 R e a c t i o n s . 7 . 3 . 1 . R e a c t i o n s w i t h H g . T h e r e a c t i o n b e t w e e n H R u C l ( n b d ) ( P P h ) a n d H p r o c e e d e d a t o n e 3 2 <\u2022 a t m o s p h e r e p r e s s u r e , , w i t h u p t a k e s c o r r e s p o n d i n g t o 2,30 a n d 2.48 m o l e s H g p e r m o l e r u t h e n i u m i n t o l u e n e a n d DMA,, r e s p e c t i v e l y ; r e a c t i o n p l o t s a r e g i v e n i n F i g u r e 7,2. a n d b o t h i n d i c a t e a r e l a t i v e l y r a p i d u p t a k e - 3 0 6 -2.5 B \u2022H Pi CD \u2022C -P P Pi 2.0 1.5 Q 0 A 0 A \u00a9A A Ok \u00a9 o B Pi 0) P< CV CD rH o 1.0 \u00a9 0.5 1 0.0 A ^_ o 400 , 800 1200 1600 Time, s 2000 20000 Figure 7 . 2 Hydrogen uptake p l o t s f o r the r e a c t i o n between Hg and HRuCl(nbd)(PPh 3) 2 i n DMA (0) and toluene (A) at 30\u00b0C: [Ru] T = 4 . 2 x 10\" M; hydrogen pressure = 760 mm Hg. of -2 Hg per Ru, followed by a much slower r e a c t i o n w i t h the f i n a l h a l f mole of Hg. P r e l i m i n a r y v i s i b l e spectrophotometric s t u d i e s of the same r e a c t i o n i n toluene at 500 nm showed a s i m i l a r r a p i d f i r s t stage, but examination of the e n t i r e spectrum i n d i c a t e d the presence of s e v e r a l species (Figure 7.3); intermediate spectra has two wave-l e n g t h maxima, w h i l e the f i n a l spectrum had only one at 500 nm, corresponding to the product,[HgRuCltPPh^)g ]g ( S e c t i o n 4.2.3). The analogue RuClg(nbd) ( P t o l ^ g was unreactive toward Hg under comparable c o n d i t i o n s . To determine more d i r e c t l y the nature of the species generated 1 31 under H 0, a combination of H and P-n.m.r. was used. - 3 0 7 -( a ) CD O C ca \u2022o u o CO ( b ) CD O c cd \u00a3> fi o CO x> 4 0 0 8 0 0 1 2 0 0 1 6 0 0 T i m e , s A a t t = 0 ; B - G a t 2 m i n i n t e r v a l s \/ H ^ ; H a t 4 5 m i n \/ H , 1 1\u2014 7 0 0 4 0 0 0 8 0 0 F i g u r e 7 . 3 500 600 W a v e l e n g t h , nm A b s o r b a n c e c h a n g e s w i t h t i m e f o r t h e r e a c t i o n b e t w e e n H R u C l ( n b d ) ( P P h 3 ) 2 a n d H g i n t o l u e n e a t 3 0 \u00b0 C : ( a ) a t 500 n m , ( b ) c o m p l e t e s p e c t r u m ; [ R u ] ^ , = 1 . 3 0 x 1 0 ~ ^M, = 7 6 0 mm H g . - 3 0 8 -H R u C l ( n b d ) ( P P h ^ ) ^ i s o n l y m o d e r a t e l y s o l u b l e i n O ^ D ^ a n d t o l u e n e - d g , b u t s h a k i n g t a n s o l u t i o n \/ s u s p e n s i o n s o f t h e c o m p l e x ( t y p i c a l l y 35-4-0 mg i n 0 .5 m L ; 0..1 M) u n d e r H g g a v e h o m o g e n e o u s r e d s o l u t i o n s w i t h i n 15-20 m i n , w h i c h r e m a i n e d h o m o g e n e o u s t h r o u g h o u t t h e c o u r s e o f t h e e x p e r i m e n t s ( u p t o 2d),, However . , - s p e c t r a w e r e o f t e n o b t a i n e d b e f o r e d i s s o l u t i o n w a s c o m p l e t e , , i n a n e f f o r t t o e x t e n d t h e i n f o r m a t i o n o b t a i n e d . T h i s e f f e c t i v e l y e x t e n d e d t h e l i f e t i m e o f H R u C l ( n b d ) ( P P h ^ ) 2 i n s o l u t i o n , , s i n c e i t w a s c o n t i n u a l l y b e i n g r e p l e n i s h e d b y d i s s o l v i n g s o l i d a n d , i n t h i s r e s p e c t , , , t h e s e e x p e r i m e n t s d i f f e r e d f r o m t h o s e o b t a i n e d i n m o r e d i l u t e s o l u t i o n s . H o w e v e r , t h e s p e c t r a o f t h e h o m o g - . e n e o u s r e d s o l u t i o n s o b t a i n e d a f t e r l o n g e r t i m e s i n c o r p o r a t e d a l l o f t h e s p e c i e s g e n e r a t e d a n d s h o u l d g i v e r e p r e s e n t a t i v e i n f o r m a t i o n a s t o t h e n a t u r e o f t h e s p e c i e s i n d i l u t e s o l u t i o n s a t l o n g e r t i m e s . On m o n i t o r i n g t h e r e a c t i o n a t r o o m t e m p e r a t u r e i n C ^ D ^ b y H - n . m . r . ( 8 0 M H z ) , , t h e d o w n f i e l d p o r t i o n o f t h e s p e c t r u m , i n a d d i t i o n t o P P h ^ r e s o n a n c e s , i n d i c a t e d o n l y a c l e a n c o n v e r s i o n o f c o o r d i n a t e d n o r b o r n a d i e n e t o n o r b o r n a n e , . c o n f i r m e d - b y c o m p a r i s o n w i t h t h e s p e c t r u m o f a n a u t h e n t i c s a m p l e ( 6 a t 1,19 (6H), 1.48 ( 4 H ) . , 2.20 (2H)) ( F i g u r e 7.4-)- N o n o r b o r h e n e , . w h i c h e x h i b i t s ' , a n o l e f i n i c r e s o n a n c e a t 6 . 0 6 , w a s e v e r d e t e c t e d d u r i n g t h e s e e x p e r i m e n t s - T h e u p f i e l d p o r t i o n o f t h e s p e c t r a s h o w e d a s e r i e s o f m e t a l h y d r i d e s p e c i e s - T h e r e s o n a n c e o f H R u C l ( P P h J 0 ( - 1 7 - 5 6 , q , 26 H z ) a p p e a r e d w i t h i n 5 m i n o f a d d i n g 3 3 H g , a n d g e n e r a l l y r e m a i n e d t h r o u g h o u t t h e d u r a t i o n o f t h e e x p e r i m e n t s (~ 24 h ) ; i t s r e l a t i v e i n t e n s i t y i n c r e a s e d t o a max imum o f - 50$ o f t h e t o t a l i n t e g r a t e d h y d r i d e i n t e n s i t y a n d t h e n d e c r e a s e d . U s u a l l y , H R u C l ( P P h \u201e ) 0 w a s t h e o n l y o t h e r s p e c i e s d e t e c t e d . , , b e s i d e s [H R u C l ( P P h \u201e ) <] 3 3 2 3 2 a n d c o n s t i t u t e d - 15-20$ o f t h e f i n a l h y d r i d e i n t e n s i t y w h e n a l l o f - 3 0 9 -F i g u r . e 7 . 4 ( s e e o v e r ) \u2022310-(d) t = 22 h free norbornane 9 8 7 6 5 4 3 2 1 06 HRuCl(PPh 3) 3 -17 . 505- , 28 Hz (e) t = 5 h HRuCl(nbd)(PPh 3) 2 -8.886, 24 Hz H 2RuCl(PPh 3) 2 2 -12.86 1 ure 7.4 (continued). H n.m.r. s p e c t r a l changes with time when HRuCl(nbd)(PPhJ\u201e was shaken with H n i n C,D, at 25\u00b0C. 3 2 2 6 6 Times indicated are reaction times a f t e r addition of Hg. Spectrum (e) gives representative high f i e l d resonances discussed i n the text. \u2022 3 1 1 -t h e s t a r t i n g H R u C l ( n b d ) ( P P h ^ ) ^ ( - 8 . 8 8 6 , t . , 24 H z ) w a s c o n s u m e d ( - 24>h). M o n i t o r i n g t h e r e a c t i o n a f t e r 2 d s h o w e d n o H R u C l t P P h ^ ) y a n d o n l y [ H 2 R u C l ( T P h 3 ) 2 ] 2 . . I n t e r e s t i n g l y a n d i n c o n t r a s t t o t h e b e h a v i o r o f H R u C l ( P P h 3 ) 3 i n o t h e r s y s t e m s ( S e c t i o n 6 . 2 ) , . n o b r o a d e n i n g o f i t s h y d r i d e r e s o n a n c e w a s o b s e r v e d i n t h e s e e x p e r i m e n t s , e v e n w h e n t h e s a m p l e s w e r e f r e s h l y c h a r g e d w i t h E^. T h e h y d r i d e r e s o n a n c e o f t h e [ H 2 R u C l ( P P h . j ) 2 ] 2 p r o d u c t ( - 1 2 . 8 6 , b r o a d ) w a s a p p a r e n t a f t e r - 1 5 m i n o f r e a c t i o n a n d i n c r e a s e d i n i n t e n s i t y t h r o u g h o u t t h e c o u r s e o f t h e r e a c t i o n . A f t e r 2 d , i t w a s t h e o n l y h y d r i d e o b s e r v e d . I n a d d i t i o n t o t h e s e m a j o r h y d r i d e r e s o n a n c e s , t w o o t h e r v e r y w e a k h i g h f i e l d s i g n a l s w e r e o b s e r v e d a t - 5 . 2 6 ( d , 7 0 H z ) a n d - 1 5 . 0 6 ( t , 34- H z ) . T h e - 5 . 2 6 s i g n a l a p p e a r e d e a r l y i n t h e r e a c t i o n s e q u e n c e ('= 2 h , F i g u r e 7 . 4 ) , a n d t h e n d i s a p p e a r e d . , , ; w h e r e a s t h e - 1 5 6 s p e c i e s a p p e a r e d o n l y a f t e r e x t e n d e d t i m e s (6r-17 h ) . B o t h w e r e r e p r o d u c i b l y p r o d u c e d i n v e r y l o w l e v e l s , , a l t h o u g h n e i t h e r c o u l d b e i d e n t i f i e d . 31 1 T h e r e a c t i o n w a s a l s o m o n i t o r e d b y P{ H } - n . m . r . a t r o o m t e m p e r a t u r e i n C ^ D ^ a n d a t - 6 0 \u00b0 C i n t o l u e n e - d g . T h e s e s p e c t r a w e r e o f l i t t l e a i d i n f u r t h e r e l u c i d a t i n g i n t e r m e d i a t e s , e x c e p t t o c o n f i r m t h e p r e s e n c e o f H R u C l t P P h ^ ) y I n . C ^ ( F i g u r e 7 . 5 ) , t h e f i r s t n e w r e s o n a n c e t o a p p e a r w a s a l s o d u e t o H R u C l ( P P h 3 ) . j ( 5 8 . 3 ppm) b u t b e c a u s e o f t h e b r e a d t h o f t h e r e s o n a n c e , i t b e c a m e a p p a r e n t a s s u c h o n l y a f t e r l o n g e r t i m e s ( - 1 h ) . A s t h e r e a c t i o n p r o c e e d e d , t h e s i g n a l s d u e t o [ H 2 R u C l ( P P h 3 ) . 2 ] 2 ( 7 0 , 8 ppm a n d 46 .0 ppm) b e c a m e a p p a r e n t a n d e v e n t u a l l y d o m i n a t e d t h e s p e c t r u m . A t i n t e r m e d i a t e t i m e s , h o w e v e r , t h e d o w n f i e l d r e s o n a n c e w a s u s u a l l y m o r e i n t e n s e t h a n t h e u p f i e l d r e s o n a n c e - ( F i g u r e 7 . 5 c ) . On o n e o c c a s i o n , , b e f o r e t h e a p p e a r a n c e o f 1 ( a ) 5 m i n - 1 h 58 .3 ppm H R u C l ( P P h 3 ) 3 4.0.5 ppm H R u C l ( n b d ) ( P P h 3 ) 2 7 ( b ) 1 h - 2 h 5 8 . 3 ppm 4 0 . 5 ppm 1 i ! c ) 2 h - 16 h 7 0 . 8 ppm 4 6 . 1 ppm [ H 2 R u C l ( P P h 3 ) 2 ] 2 \u00bbWM-NJW^^ toy W ( d ) 20 h - 21 h 7 0 . 8 ppm 4 6 . 1 ppm [ H 2 R u C l ( P P h 3 ) 2 ] 2 31 \"I o F i g u r e 7 . 5 P{ H } - N . i n . r . s p e c t r a l c h a n g e s a t 2 5 C w i t h t i m e f o r t h e r e a c t i o n b e t w e e n H R u C l ( n b d ) ( P P h 3 ) 2 a n d R*2 i n C ^ D ^ . T i m e s q u o t e d a r e a f t e r a d d i n g R~2 a n d r e f e r t o t i m e s o f d a t a a c c u m u l a t i o n . t h e s i g n a l s o f [ H g R u C ^ P P h ^ ) 2 ] ^ , a ^ P f p h e n y l p r o t o n } - n . m . r . s p e c t r u m s h o w e d t h e p r e s e n c e o f a d o u b l e t a t 70 .64 p p m , w i t h a c o u p l i n g t o h y d r i d e o f 31 H z . T h i s s i g n a l p o s s i b l y a c c o u n t s f o r t h e u n e q u a l i n t e n s i t i e s o f t h e [ H g R u C l C P P h ^ ) r e s o n a n c e s , b u t t h e s p e c i e s r e s p o n s i b l e w a s n o t i d e n t i f i e d . T h e H R u C l ( n b d ) ( P P h ^ ) g c o m p l e x w a s c o n s i d e r a b l y l e s s s o l u b l e i n t o l u e n e - d D , a n d s o t h e o b s e r v e d c h a n g e s w e r e c o r r e s p o n d i n g l y s l o w e r 8 31 1 t h a n i n b e n z e n e . H o w e v e r , o n m o n i t o r i n g t h e r e a c t i o n w i t h P{ H } -n . m . r . a t - 6 0 \u00b0 C ( F i g u r e 7 . 6 ) , t h e o n l y s i g n a l s o b s e r v e d w e r e t h o s e o f H R u C l ( P P h 3 ) 3 ( 9 5 . 5 p p m , t ; 3 7 . 7 p p m , d ; 2 J p p = 2 7 H z ) a n d [ H 2 R u C l ( P P h 3 ) 2 ] 2 ( 7 9 . 6 , 6 2 . 3 , 2 9 . 0 p p m ; r e l a t i v e i n t e n s i t y 1 : 2 : 1 ) w h i c h a p p e a r e d a t a p p r o x i m a t e l y t h e t i m e s i n d i c a t e d a b o v e . M o s t i m p o r t a n t l y , t h e r e w a s n o e v i d e n c e f o r t h e i n t e r m e d i a t e A B C D s p e c i e s d e f i n e d i n C h a p t e r 5 . 7 . 3 . 2 . R e a c t i o n w i t h C O . T h e c o m p l e x H R u C l ( n b d ) ( P P h 3 ) 2 r e a c t e d c l e a n l y a n d i r r e v e r s i b l y i n t o l u e n e a n d DMA a t 1 a t m , CO t o a b s o r b 2 . 8 t o 3 . 0 e q u i v a l e n t s o f c a r b o n m o n o x i d e . T h e l o w e r v a l u e s w e r e o b t a i n e d i n t o l u e n e s y s t e m s , i n d i c a t i n g p e r h a p s t h a t some u p t a k e o c c u r r e d i n t h e s o l i d s t a t e p r i o r t o d i s s o l u t i o n i n t h e s o l v e n t . U s i n g t h e g a s e n t r y t e c h n i q u e a t 1 a t m , ( s e e S e c t i o n 2 . 4 ) , 2 . 5 e q u i v a l e n t s o f CO p e r e q u i v a l e n t o f r u t h e n i u m w e r e t a k e n u p r e l a t i v e l y q u i c k l y ( c a . 5 t o 1 0 m i n ) w h i l e t h e r e m a i n i n g 0 . 5 e q u i v a l e n t s w e r e a b s o r b e d o v e r 1 h o u r . H o w e v e r , m o n i t o r i n g t h e 31 1 r e a c t i o n b y P { H } - n . m . r . i n C ^ D ^ g a v e n o i n d i c a t i o n o f a n y l o n g -l i v e d , p h o s p h i n e - c o n t a i n i n g s i d e p r o d u c t s o r i n t e r m e d i a t e s , o r f r e e P P h ^ w h i c h w o u l d i n d i c a t e p h o s p h i n e d e f i c i e n t i n t e r m e d i a t e s ( F i g u r e 7 . 7 ) . 4-0.7 ppm. H R u C l ( n b d ) ( P P h 3 ) 2 3 0 m i xn I*1 _a IT*.\" '*>' 3 h 9 5 . 3 ppm 3 7 . 7 ppm H R u C l ( P P h 3 ) 3 2 9 . 0 ppm.,. [ H 2 R u C l ( P P h 3 ) 2 ] 2 F i g u r e 7 . 6 ( s e e o v e r ) . -315-( c o n t i n u e d ) . P { H } - j N . m . r . s p e c t r a l c h a n g e s a t - 6 0 \u00b0 C w i t h t i m e f o r t h e r e a c t i o n b e t w e e n H R u C l ( n b d ) ( P P h ^ ) ^ a n d H g i n t o l u e n e - d g . T i m e s g i v e n : a r e r e a c t i o n t i m e s a t room..: t e m p e r a t u r e . - 3 1 6 -J p H = 24 H z 4O.6 ppm ( a ) 3 1 P { 1 H } u n d e r a r g o n . 3 0 . 6 ppm ( b ) 3 1 P { p h e n y l } 1 0 m i n \/ C O ( c ) 3 1 P { p h e n y l } 18 h \/ C O -1 1 1 1 r ~ T 1 1 r~ ~1 1 1 1 r-F i g u r e 7 . 7 C h a n g e s i n 3 ^ P - n . m . r . s p e c t r u m a t 3 0 \u00b0 C w i t h t i m e w h e n H R u C l ( n b d ) ( P P h 3 ) 2 w a s s h a k e n w i t h CO i n C ^ D ^ ; s p e c t r u m ( c ) i s a t t w i c e h o r i z o n t a l e x p a n s i o n a n d s h o w s r e s i d u a l s t a r t i n g m a t e r i a l . -317-31 The i s o l a t e d product, the'. P{phenyl proton}.-n.nur. \u2022 resonance of which 31 1 1 appeared as a s i n g l e t a t 30.6 ppm, had i d e n t i c a l P{ H}- and H-n.m.r. parameters as the species generated i n s i t u , i n d i c a t i n g no GO l o s s i n the workup. The elemental a n a l y s i s of the i s o l a t e d product (Found: C: 65.88; H: 4.6O; CI: 4.04$) was c o n s i s t e n t w i t h the uptake data and i n d i c a t e d the stoic h i o m e t r y RuCl(CO)_(C\u201eHn)(PC.0H\u201e_)_ 3 \/ y 18 15 2 (Calc'd f o r C . ,H_nC10\u201ePoRu: C: 65.91; H: 4.69; CI: 4.12$). 4o 39 3 2 The i n f r a r e d spectrum (Figure 7.8) showed a v p n p a t t e r n c o n s i s t e n t GU w i t h trans c a r b o n y l s 2 0 1 ( v C Q at 2010(w), 1935(vs), 1905(sh)) and a ke t o n i c s t r e t c h a t 1604 cm 1 The H-n.m.r. of the product (Fi g u r e 7.9) showed, i n a d d i t i o n t o the phenyl resonances of PPh^, nine r e s o l v e d resonances of equal i n t e n s i t y downfield of TMS (Table V I I - 1 ) . A s e r i e s of s e l e c t i v e homo-nuclear decoupling experiments were done to determine the magnitudes 2000 ' . . -.1600 -.- ' 1200 Wavenumber, cm~ Figure 7.8. I n f r a r e d spectrum of RuCKCO.C^) ( C 0 ) 2 ( P P h 3 ) 2 as a KBr p e l l e t . J J JJL 5 . 8 5 6 0 . 8 6 6 JL 11 . J J M J U L 4 1 0 1T F i g u r e 7.'9 ' H - N . m . r . s p e c t r u m o f R u C l ( C 0 . C H ) (CO) ( P P h 0 ) 0 i n C , D , a t 3 5 \u00b0 C a n d 4OO M H z ; i n s e r t s 7 9 <\u2022 3 <\u2022 0 0 g i v e e x p a n d e d r e s o n a n c e s o f n o r b o r n e n o y l p r o t o n s ( T a b l e V I I - 1 ) . x i n d i c a t e s i m p u r i t i e s . 00 - 3 1 9 -T A B L E V I I - 1 . M e a s u r e d 1 H a n d 1 3 C { 1 H } - n . m . r . p a r a m e t e r s f o r ? . : i C T : ( C 0 . G r \/ i . r \u201e ) ( 0 0 ) 2 ( P P r ) i n C , D , a t 2 5 \u00b0 C 6 H , p . p . m . a A s s i g n m e n t 6. C{ H } , p . p . m . A s s i g n m e n t 0 . 8 6 ( d , m ) 7 a 3 2 . 3 ( t ) C - 3 1 . 0 4 ( d , d , d ) 3 n 4 3 . 3 ( d ) C - 4 1 . 1 3 ( d , d , m ) 7 s 46.8 ( d ) C - 1 1 . 2 5 ( d , d ) 3 x 4 9 . 1 ( t ) C - 7 2 . 5 2 ( m ) 4 6 0 . 5 ( d ) C-2 2 . 6 2 ( m ) 1 1 3 2 . 9 ( d ) C - 6 4 . 5 3 ( d , d , d ) 2 x 1 3 6 . 5 ( d ) C - 5 5 . 8 5 ( d , d ) 6 2 0 3 . 3 ( t )d C-9 6 . 1 3 ( d , d ) 5 2 4 3 . . S ( t )d C - 8 7 . 1 l ( m ) P P h 3 1 2 8 . 6 e P P h 3 7 . 9 4 ( m ) P P h 3 1 3 0 . 4 6 P P h 3 1 3 5 . 0 e P P h 3 a A t 400 M H z . A b b r e v i a t i o n s i n p a r e n t h e s e s r e f e r t o o b s e r v e d m u l t i p l i c i t y i n t h e a b s e n c e o f h o m o n u c l e a r d e c o u p l i n g ; d = d o u b l e t , t .= t r i p l e t , m;= u n r e s o l v e d m u l t i p l e t . b F o r l a b e l l i n g s c h e m e , s e e F i g u r e 7 7 , 1 0 . F o r r a t i o n a l e o f a s s i g n m e n t s , s e e t e x t . c O b t a i n e d a t n a t u r a l a b u n d a n c e a t 1 0 0 M H z ; p o s i t i v e s h i f t s a r e d o w n f i e l d f r o m M e ^ S i w i t h C ^ D ^ a t 1 2 8 . 0 p . p . m . A b b r e v i a t i o n s i n p a r e n t h e s e s g i v e s p l i t t i n g o b s e r v e d f r o m S F 0 R D e x p e r i m e n t , u n l e s s o t h e r w i s e i n d i c a t e d . - 3 2 0 -T a b l e V I I - 1 ( c o n t i n u e d ) d C o u p l i n g d u e t o p h o s p h o r u s n u c l e i ( 2 j ( 1 3 C 0 - P ) = 7 . 6 H z ; 2 j ( 1 3 C n - P ) = 1 5 . 1 H z ) . T h e r e s o n a n c e d u e t o t h e a c y l c a r b o n ( C - 8 ) w a s d i s t o r t e d a s s h o w n i n F i g u r e ' 7 . 1 1 b . e A s s i g n e d n o n - s p e c i f i c a l l y t o t h e P P h ^ r e s o n a n c e s ; s e e t e x t . T A B L E V I I - 2 . C o u p l i n g c o n s t a n t s J ( H - H ) a f o r R u C l ( C 0 . C 7 H ) ( C 0 ) 2 ( P P h 3 ) 2 J ( 1 . _ 2 X ) = 3 . 6 H z j ( 3 x-4') = 3 . 9 H z J ( 1 - 6 ) = 2 . 8 H z J(4 - 5 ) = 3 . 0 H z J ( 2 x - 3 n ) = 5 . 0 H z J(4 - 7 a ) = 2 . 0 H z J ( 2 x - 3 x ) = 9 . 0 H z J ( 5 - 6 ) = 5 . 5 H z J ( 3 n - 3 x ) = 1 1 . 0 H z J ( 7 a - 7 s ) = 8 . 0 H z J ( 3 n - 7 s ) = 2 . 0 H z b a A t 4-00 MHz i n C ^ D ^ a t 25 C ; a l l c o u p l i n g s n o t l i s t e d w e r e l e s s t h a n o r c o m p a r a b l e t o t h e r e s o l u t i o n o f t h e i n s t r u m e n t . b R e s o l v e d o n l y i n t h e r e s o n a n c e d u e t o 3 n ; s e e t e x t . - 3 2 1 -o f t h e c o u p l i n g c o n s t a n t s a n d a s s i g n t h e r e s o n a n c e s ( T a b l e V I I - 2 ) . 1 3 1 -< T h e C{ H } - n . m . r . s p e c t r u m i s g i v e n i n F i g u r e 7 . T 4 . T h e u p f i e l d p o r t i o n o f t h e s p e c t r u m s h o w e d f i v e w e l l s e p a r a t e d r e s o n a n c e s f o r t h e s a t u r a t e d c a r b o n s i n t h e o r g a n i c m o i e t y . T h e m u l t i p l i c i t i e s o f t h e s e w e r e d e t e r m i n e d b y a s i n g l e - f r e q u e n c y - o f f - r e s o n a n c e - d e c o u p l i n g ( S F O R D ) e x p e r i m e n t . T h e p o r t i o n o f t h e s p e c t r u m s l i g h t l y d o w n f i e l d f r o m t h e \" r e s o n a n c e s ' due..-to.. G-^Dg ( F i g u r e 7-vTTa ' ) ' - showed- t h r e e r e s o n a n c e s a t t r i b u t a b l e t o P P h ^ , t w o a t t r i b u t a b l e t o f r e e o l e f i n , a n d a m u l t i p l e t p a t t e r n o f u n k n o w n o r i g i n . T h e c o o r d i n a t e d c a r b o n m o n o x i d e s e x h i b i t e d a s i n g l e t r i p l e t r e s o n a n c e ( 2 0 3 . 3 2 p p m , J p ^ = 1 5 . 1 H z ) , i n d i c a t i n g c o u p l i n g t o t w o p h o s p h i n e s . T h e e x p e c t e d t r i p l e t r e s o n a n c e f o r t h e a c y l c a r b o n (24.3.0 ppm) w a s d i s t o r t e d , p o s s i b l y d u e t o r e l a x a t i o n e f f e c t s ' 2 0 2 J . t he ' c o u p l i n g - c o n s t a n t ( J p C -\" '7^.6 ' H z ' ) - b e i n g m e a s u r e d a s s h o w n i n F i g u r e 7 . T i b . 7s 7a 3x 6 F i g u r e 7 .1 .0 A p p a r e n t s k e l e t a l a r r a n g e m e n t o f t h e a c y l m o i e t y i n R u C 1 ( C O . C ? H 9 ) ( C O ) 2 ( P P h 3 ) 2 . 1 5 0 F i g u r e , 7 . 1 1 1 2 0 9 0 \u2014 i \u2014 6 0 30 ppm 1 3 C { 1 H } - N . m . r . s p e c t r u m o f R u C l C C O . C ^ ) ( C 0 ) 2 ( P P h 3 ) 2 i n C ^ D ^ a t 2 5 \u00b0 C ; i n s e t ( a ) i s e x p a n s i o n o f d o w n f i e l d r e g i o n ; i n s e t ( b ) a n d ( c ) g i v e s r e s o n a n c e s f o r a c y l a n d t e r m i n a l c a r b o n y l s , r e s p e c t i v e l y . -323-7 . 3 . 3 . R e a c t i o n w i t h 00^. T h e c o m p l e x H R u C l ( n b d ) ( P P h ^ ) 2 s h o w e d n o C O ^ u p t a k e i n t o l u e n e a f t e r 2 h a t 3 0 \u00b0 C a n d 1 a t m o s p h e r e p r e s s u r e . A s i n g l e u p t a k e i n DMA g a v e a n u p t a k e c o r r e s p o n d i n g t o 0.95 C O ^ p e r R u , b u t 4 s u b s e q u e n t a t t e m p t s t o r e p r o d u c e t h i s s h o w e d a b s o l u t e l y n o r e a c t i o n . T h e 3 \" ' p { ' ' H } - n . m , r . s p e c t r u m a t -6'5\u00b0C o f t h e s o l u t i o n - r e s u l t i n g w h e n H R u C l ( - n b d , ) : ( P P h 3 ) . - 2 \" ( ' 3 0 mg.,'0..04 mmol ) was. s h a k e n - u n d e r d r y C O ^ i n D M A \/ t o l u e n e - d g \" (1:1 v\/v, 0.^5 mL) a t 3 0 \u00b0 C f o r 30 m i n . c o n s i s t e d o n l y , o f a r e s o n a n c e a t 4O..8-ppm, i d e n t i f i e d a s s t a r t i n g m a t e r i a l b y c o m p a r i s o n w i t h a n , , a u t h e n t i c s a m p l e u n d e r a r g o n . 7 . 3 . 4 ' . A t t e m p t e d p r e p a r a t i o n o f R u H ( 0 o C C H o ) ( n b d ) ( P P h J <\u2022 J 3 2 I n a n a t t e m p t t o o b t a i n a b ' i s ( p h o \u00bb p > : . : no ) . ' a c e t , a t e _ p r e c u r s o r f o r s u b s e q u e n t r e a c t i o n w i t h h y d r o g e n t o f o r m t h e c a r b o x y l a t e a n a l o g u e o f [ R ~ 2 R u C l ( P P h 3 ) 2 ] 2 , t h e r e a c t i o n o f H R u ( O A c ) ( P P h ^ ) ^ w i t h n o r b o r n a d i e n e w a s e x a m i n e d . W.e h o p e d t o e i t h e r f o r m t h e c o r r e s p o n d i n g H R u ( O A c ) ( n b d ) ( P P h ^ ) 2 c o m p l e x w i t h m o n o d e n t a t e a c e t a t e o r t r a p t h e o l e f i n i n s e r t i o n p r o d u c t w i t h t h e b i d e n t a t e a c e t a t e . A d d i t i o n o f n o r b o r n a d i e n e ( 3 0 mL) t o a y e l l o w s u s p e n s i o n o f H R u ( O A c ) ( P P h ^ ) ^ ( 1 . 0 g , I.05 m m o l ) i n b e n z e n e (25 mL) c a u s e d t h e m i x t u r e t o c l e a r t o a p a l e o r a n g e s o l u t i o n . T h i s w a s s t i r r e d a t r o o m t e m p e r a t u r e f o r c a . 12 h a n d f i l t e r e d i n t o p e t r o l e u m e t h e r s ( ' 3 0 \u00b0 C-60 O C ) (-1 OOmL) . N o c h a n g e w a s o b s e r v e d , e v e n a f t e r 3 d a y s . R e d u c i n g t h e s o l u t i o n v o l u m e b y 50% u n d e r v a c u u m c a u s e d a y e l l o w s o l i d t o d e p o s i t . T h i s w a s f i l t e r e d , w a s h e d w i t h p e t r o l e u m e t h e r a n d v a c u u m d r i e d . ( 2 4 . h ) t o y i e l d o n l y s t a r t i n g m a t e r i a l , H R u ( O A c ) ( P P h ^ ) ^ ( 0 . 7 3 g , 7 0 $ ) , , a s - 3 2 4 -i d e n t i f i e d b y H - n . m . r . (Ru^-H r e s o n a n c e a t r- 17.676, q , 27 H z ) a n d _-| i . r . ( K B r , VQQQ a t 154-0, 1460 cm ) . T o d e t e r m i n e t h e n a t u r e o f t h e o r a n g e s o l u t i o n , H R u ( O A c ) ( P P h ^ ) ^ ( 4 0 m g , 4 x 10 m m o l ) a n d n o r b o r n -31 a d i e n e (0.1 mL) w e r e d i s s o l v e d i n C ^ ( 0 . 5 mL)- . T h e P { p h e n y l } -n . m . r . o f t h e r e s u l t i n g s o l u t i o n s h o w e d o n l y o n e s i n g l e t a t -4.8 p p m , a t t r i b u t a b l e t o f r e e P P h ^ . , i n d i c a t i n g t h a t t h e n o r b o r n a d i e n e h a d r e p l a c e d a l l o f t h e p h o s p h i n e l i g a n d s . 7.4 D i s c u s s i o n . T h e c o m p o u n d H R u C l ( n b d ) ( P P h ^ ) 2 w a s f i r s t r e p o r t e d 2 7 i n 1968 b y W i l k i n s o n a n d c o - w o r k e r s - a n d b e c a u s e o f t h e l a r g e n u m b e r o f r e s o n a n c e s d u e t o n o r b o r n a d i e n e , . w a s c o n s i d e r e d t o b e p o s s i b l y a m i x t u r e o f i s o m e r s ( I a - c ) : T h e r e s o n a n c e a t 0.906 w a s a s s i g n e d t o t h e m e t h y l e n e p r o t o n s , w h i l e t h e r e m a i n i n g f o u r r e s o n a n c e s w e r e a s s i g n e d n o n - s p e c i f i c a l l y t o t h e 31 1 r e s t . T h e p r e s e n t P { H } ^ - n . . m . r . d a t a i n d i c a t e t h e p r e s e n c e o f a 1 31 s i n g l e i s o m e r w i t h e q u i v a l e n t - p h o s p h i n e s . . T h e H{ P } - n . m . r . s p e c t r u m c l e a r l y shows- t h a t t h e r e s o n a n c e s a t 3.63 a n d 3.456 a r e t h o s e o f t h e o l e f i n i c p r o t o n s . T h e r e s u l t i n g p a t t e r n ( F i g u r e 7.1, i n s e t ) i s c o n s i s t e n t - 3 2 5 -o n l y w i t h a s t r u c t u r e I I i n w h i c h H ( a ) a n d H ( b ) a r e i n d i f f e r e n t e n v i r o n m e n t s f r o m H ( d ) a n d H ( c ) . , r e s p e c t i v e l y ; o n l y i s o m e r I - a a c c o u n t s f o r a l l t h e new n . m . . r . d a t a . T h e p s e u d o t r i p l e t a p p e a r a n c e o f t h e p h o s p h o r u s - d e c o u p l e d r e s o n a n c e s s u g g e s t s a n a p p r o x i m a t e n u m e r i c a l 2 2 e q u i v a l e n c e o f t h e c o u p l i n g c o n s t a n t s ^ j j ( a ) H ( b ) ~ ^ H ( b ) H ( c ) ~ 2 J T T , .. T T , l N - 3 . 8 H z , w h i c h i s c o n s i s t e n t w i t h o t h e r w o r k 1 9 9 - ' 2 0 2 , a n d H ( c ) - H t d ) 16 9 i s e x p l a i n e d o n t h e b a s i s o f g e o m e t r y . T h e d i f f e r e n c e i n s h a p e s o f t h e o l e f i n i c r e s o n a n c e s i n t h e n o n d e c o u p l e d s p e c t r u m ( F i g u r e 7 . 1 ) r e s u l t s f r o m s l i g h t l y d i f f e r e n t . c o u p l i n g s t o t h e p h o s p h i n e l i g a n d s . T h i s l i k e l y a r i s e s f r o m some d i s t o r t i o n f r o m i d e a l i z e d g e o m e t r y b y w h i c h t h e b u l k y p h o s p h i n e s \" b e n d \" t o w a r d t h e s m a l l h y d r i d e l i g a n d T h e n . m . r , \u2022 d a t a f o r t h e p r o p o s e d s t r u c t u r e i s a t v a r i a n c e w i t h t h e e m p i r i c a l s u g g e s t i o n r e c e n t l y p u t . f o r w a r d b y M o o r e a n d R o b i n s o n 1 6 7 f o r d e t e r m i n i n g t h e r e l a t i v e d i s p o s i t i o n s o f t r l p h e n y l p h o s p h l n e s a n d - a r s i n e s . T h e s e a u t h o r s h a v e r e p o r t e d t h a t f o r 6 0 p l a t i n u m m e t a l c o m p l e x e s ( n o t s p e c i f i e d ) . , t h e c h e m i c a l s h i f t d i f f e r e n c e , A 6 , i n C ^ D ^ o f t h e o r t h o a n d m e t a \/ p a r a p r o t o n s i s l e s s t h a n 0 . 5 ppm f o r c i s p h o s p h i n e s a n d g r e a t e r t h a n 0 , 5 ppm f o r t r a n s p h o s p h i n e s , a n d - 3 2 6 -t h a t t h i s s e p a r a t i o n d i f f e r e n c e i s \" r e m a r k a b l y i r r e s p o n s i v e \" t o c h a n g e s i n t h e i d e n t i t y o f t h e m e t a l a t o m , g e o m e t r y , o x i d a t i o n s t a t e , a n d n a t u r e o f t h e a u x i l i a r y l i g a n d s . T h e c o m p o u n d H R u C l ( n b d ) ( P P h ^ ) , - , , b e l i e v e d t o c o n t a i n c i s p h o s p h i n e s , h a s a s h i f t d i f f e r e n c e , A 6 , o f 0 . 7 3 p p m . T h e a n o m a l y may b e e x p l a i n e d b y e x a m i n i n g t h e t h e o r e t i c a l b a s i s o f t h e s u g g e s t e d c o r r e l a t i o n . T h e s e p a r a t i o n s a r i s e b e c a u s e I n t e r l e a v i n g - b e n z e n e s o l v e n t ' . m o l e c u l e s p r e f e r e n t i a l l y ' s h i e l d t h e m e t a a n d p a r a p r o t o n s w h i l e d e s h i e l d i n g t h e o r t h o p r o t o n s 9 6 . T h e d e g r e e o f t h i s \u2022 i n t e r a e t i o n \u201e . _ i s d e p e n d e n t o r i - - d i p o l e i n d u c e d i n t e r a c t i o n s . I n t r a n s i t i o n m e t a l c o m p l e x e s , , l i g a n d s o f h i g h t r a n s \u2022 i n f l u e n c e t r a n s t o p h o s p h i n e s c a u s e l e n g t h e n i n g a n d i n c r e a s e s i n t h e d i p o l e m o m e n t s f o r t h e M - E P h ^ ( E = P , A s ) b o n d s . . C o n s e q u e n t l y , i n t h e s e c a s e s , t h e -. b e n z e n e i n t e r a c t i o n s 1 a r e s t r o n g e r a n d t h e s e p a r a t i o n s l a r g e r . H o w e v e r , w h i l e M o o r e a n d R o b i n s o n a p p a r e n t l y c o n s i d e r e d t h a t o n l y p h o s p h i n e s - e x e r t a h i g h t r a n s i n f l u e n c e , l i g a n d s s u c h a s h y d r i d e s , C O , a n d o l e f i n s , e x e r t e v e n s t r o n g e r e f f e c t s 1 3 3 , a n d s h o u l d a l s o b e e x p e c t e d t o p r o d u c e l a r g e s p l i t t i n g s f o r e x a c t l y t h e same r e a s o n s . I n c a s e s w h e r e s u c h l i g a n d s a r e p r e s e n t , t h e n , t h e m e t h o d h a s t h e p o t e n t i a l o f f a l l i n g s h o r t o f i t s r e p o r t e d g e n e r a l i t y a n d u s e f u l n e s s . T h e a p p a r e n t s t a b i l i t y o f t h e H R u C l ( n b d ) ( P P h ^ ) ^ c o m p l e x i s s o m e w h a t r e m a r k a b l e i n v i e w o f t h e r e l a t i v e p o s i t i o n s o f t h e h y d r i d e a n d o l e f i n l i g a n d s . T h e c o p l a n a r a r r a n g e m e n t o f m e t a l , h y d r i d e , a n d a l k e n e - T T - b o n d i s g e n e r a l l y r e g a r d e d a s a f o u r - c e n t e r t r a n s i t i o n s t a t e f o r t h e h i g h l y s t e r o s p e c i f i c m i g r a t i o n - i n s e r t i o n o f o l e f i n s i n t o m e t a l h y d r i d e b o n d s 1 \u00bb 3 > 1 9 . H o w e v e r , t h e h y d r i d e r e s o n a n c e , w h i c h m i g h t b e b r o a d e n e d i f a r a p i d i n s e r t i o n - e l i m i n a t i o n e q u i l i b r i u m w e r e o p e r - . . a t i v e , w a s s h a r p s u g g e s t i n g . n o m e a s u r a b l e d y n a m i c p r o c e s s ( e q u a t i o n 7 . 1 ) . - 3 2 7 -I \u201e I Ru L.Ru 1 L ^ j 3 1 ( 7 . 1 ) T h e h y d r i d o - o l e f i n c o m p l e x a l s o r e m a i n e d a s s u c h i n t h e d o n o r s o l v e n t s DMA a n d C D ^ C N , a n d i n t h e p r e s e n c e o f C O ^ , d e s p i t e t h e a p p a r e n t s t a b i l i t y o f t h e e x p e c t e d u l t i m a t e p r o d u c t ^ R u C l l - O - G R ) ( P P h ' ^ ^ D M A ) . ( C h a p t e r 6 ) V i n t h e l a s t c a s e . R e a c t i o n w i t h CO., h o w e v e r . , d o e s p r o m o t e t h e i n s e r t i o n r e a c t i o n . F r o m t h e d a t a p r e s e n t e d i n S e c t i o n 7 . . 3 . 2 , t h e r e a c t i o n p r o d u c t a p p e a r s t o a r i s e f r o m c o n s e c u t i v e o l e f i n a n d CO i n s e r t i o n r e a c t i o n s , a n d i s b e s t f o r m u l a t e d a s a m o n o h a p t o a c y l d i c a r b o n y l d e r i v a t i v e . . T h e n . m . r . 1 1 3 31 d a t a ( H , C , P ) i n d i c a t e t h a t t h e o r i g i n a l h y d r i d e h a s b e e n i n c o r -p o r a t e d s t e r e o s p e c i f i c a l l y i n t o t h e o r g a n i c m o i e t y . C o n s i d e r i n g t h e g e o m e t r y a r o u n d , t h e r u t h e n i u m c e n t e r . . , o n l y I I I . \" i s ^ c o n s i s t e n t w i t h t h e s p e c t r o s c o p i c d a t a ( t r a n s CO., e q u i v a l e n t P P h ^ ' s ) , w h i l e t h e 1 1 3 1 H a n d C{ H } - n , m . . r . s p e c t r a f o r t h e o r g a n i c m o i e t y a r e i n t e r p r e t e d i n t e r m s o f a n a c y l m o n o - e n e ( F i g u r e 7 . 1 0 ) , \u2022 \" O n c e - - t h e n a t u r e o f t h e P C l ^ l ^ C 0 C 0 - ^ ^ C - R R = C-fi-ll 7 9 P \u00b0 P = P P h 3 ( I I I ) o r g a n i c s k e l e t o n i s a s s u m e d , t h e a s s i g n m e n t s a r e s t r a i g h t f o r w a r d . T h e v a l u e s o f ^ a r e e n t i r e l y c o n s i s t e n t w i t h t h e k n o w n c o u p l i n g s f o r t h i s s k e l e t a l a r r a n g e m e n t 2 0 4 \" . 2 0 7 a n d t h e a s s u m p t i o n -seems v a l i d . I n f a c t , t h e p a r i t y o f J . v a l u e s i n t h i s c o m p o u n d a n d o r g a n i c a n a l o g u e s -328-s u c h a s I V ( p . 329) s u g g e s t s v e r y l i t t l e d i s t o r t i o n o f t h e n o r b o r n e n o y l m o i e t y o n c o o r d i n a t i o n . I n t h e f o l l o w i n g d i s c u s s i o n , t h e c a r b o n p o s i t i o n s a n d h y d r o g e n s a r e n u m b e r e d a c c o r d i n g t o t h e I U P A C n o m e n -c l a t u r e f o r b i c y c l i c t e r p e n e s , . w i t h common n a m e s . I n a d d i t i o n , t h e l e t t e r s n a n d x a r e a d d e d t o t h e i n u m b e r - o f ' t h e - ' h y d r o g e n , t o d e n o t e e n d o . a n d e x o , r e s p e c t i v e l y . F o r t h e 7 - h y d r o g e n s , s s p e c i f i e s t h e p r o t o n s y n t o t h e d o u b l e b o n d a n d a d e s i g n a t e d t h e a n t i p r o t o n , T h e a s s i g n m e n t o f t h e 7j3 a n d 7a b r i d g e p r o t o n s a r e b a s e d ' o n t h e f i n d i n g o f M a r c h a n d a n d R o s e 2 0 7 t h a t , i n n o r b o r n e n e , t h e a n t i b r i d g e p r o t o n ' \" . - r e s o n a t e s a t h i g h e r f i e l d t h a n d o e s t h e s y n b r i d g e p r o t o n . C o n s i s t e n t w i t h t h i s a s s i g n m e n t i s t h e o b s e r v a t i o n t h a t t h e r e s o n a n c e a t I . O 4 6 i s c o u p l e d t o t h r e e p r o t o n s , w h i l e s e l e c t i v e d e c o u p l i n g e x p e r i m e n t s a c c o u n t d i r e c t l y f o r o n l y t w o o f t h e s e , n a m e l y H a n d H . . T h e m a g n i t u d e o f J5X 4 t h e r e m a i n i n g J v a l u e (2 H z ) , a n d t h e e n d o a s s i g n m e n t o f t h i s r e s o n a n c e , i n d i c a t e t h a t t h e c o u p l i n g i s d u e t o a l o n g r a n g e i n t e r a c t i o n w i t h t h e 7s p r o t o n , i n a c c o r d w i t h t h e ' \u2022\"Wr-let ' ter- ' ' r u l e f o r t h i s f r a m e w o r k . B o t h r e s o n a n c e s a t 0,86 a n d 1,1.36 a r e s i g n i f i c a n t l y b r o a d e n e d b y u n r e s o l v e d c o u p l i n g t o H a n d H ( t y p i c a l l y 1 t o 2 H z ) . H o w e v e r , o n i r r a d i a t i o n o f . t h e r e s o n a n c e s a t 2..526 ( H . ) ' o r 2 . 6 2 6 ( H . ) t h e 0 . 8 6 6 4 1 s i g n a l s h a r p e n s t o g i v e a . v A o f . 2 . 3 H z , a n d t h e V i o f t h e r e s o n a n c e 2 s a t 1 .136 r e m a i n s g r e a t e r t h a n 5 H z , O n l y t h e 1 .136 r e s o n a n c e c a n a c c o m m o d a t e . t ' t h e . : ; 2 - H z c o u p l i n g , , ' ' a n d - - t h i s . i s . a l s o c o n s i s t e n t w i t h t h e H _ a s s i g n m e n t . 7s to O f p a r t i c u l a r i n t e r e s t , t h e v a l u e s o f | J _ . . . . | (3.9 H z ) a n d Jx-4 | 3 J 1 2 | (3.6 H z ) a r e w i t h i n t h e r a n g e (3 t o 4 H z ) f o u n d 2 0 6 f o r t h e c o u p l i n g c o n s t a n t s b e t w e e n a b r i d g e h e a d p r o t o n t o a n e x o p o s i t i o n i n n o r b o r n e n e s y s t e m s , r e a f f i r m i n g t h e s e a s s i g n m e n t s . T h e a c y l s u b s t i t u e n t -329-o c c u p i e s t h e t h e r m o d y n a m i c a l l y l e s s f a v o r e d e n d o p o s i t i o n . T h e a s s i g n m e n t s o f t h e c a r b o n r e s o n a n c e s o f t h e n o r b o r n e n y l r e s i d u e a r e s t r a i g h t f o r w a r d 2 0 8 \/ b e i n g ' . b a s e d w a n SFORD e x p e r i m e n t a n d a n a l o g y - t o - t h e ' f i n d i n g s . o f - G r u t z n e r a n d c o w o r k e r s 2 0 ? . R e s o n a n c e s a t 203.3 a n d 243.0 ppm a r e e n t i r e l y c o n s i s t e n t w i t h c o o r d i n a t e d c a r b o n m o n o x i d e s a n d a c y l c a r b o n s . , , r e s p e c t i v e l y , w h i l e t h e m e a s u r e d c o u p l i n g 2 *i 3 c o n s t a n t s J ( C - ? ) a r e i n e x c e l l e n t a g r e e m e n t w i t h v a l u e s f o u n d b y o t h e r w o r k e r s f o r s i m i l a r s y s t e m s 2 0 2 . X n ( I V ) T h e c h e m i c a l s h i f t o f C T 2 a t 6 0 . 5 ppm i n t h e r u t h e n i u m c o m p o u n d s ( I V ; X n = C 0 . R u C l ( C 0 ) 2 ( P P h 3 ) 2 ) i s s i g n i f i c a n t l y , f u r t h e r d o w n f i e l d t h a n f o u n d f o r t h e p u r e l y o r g a n i c a n a l o g u e s ( ^ n = C O O H , C O O C H ^ ; 46 ppm) b u t i s c o m p a r a b l e w i t h t h e s h i f t s f o u n d f o r m o r e e l e c t r o n e g a t i v e s u b s t i t - . \\ u e n t s ( X n = O H , O C H ^ ; ,73 p p m , X n = N H 2 ; 53 p p m ) 2 0 8 . T h i s a p p a r e n t l y h i g h e l e c t r o n e g a t i v i t y o f t h e a c y l r u t h e n i u m m o i e t y i s a l s o s e e n i n t h e d o w n f i e l d s h i f t o f . t h e H \u201e (4 - 5 3 6 ; c f . X = C 0 0 C H o a t 2 . 9 0 6 ; X = 2 x \u2014 n 3 n OH a t 4 - 3 5 6 ) 2 0 6 - H o w e v e r , t h i s p h e n o m e n o n i s n o t o b s e r v e d i n o t h e r r u t h e n i u m a c y l s p e c i e s ; f o r e x a m p l e . , t h e a c e t y l r e s o n a n c e s i n R u ( C 0 . C H 3 ) ( C 0 ) 2 ( P M e 2 P h ) 2 2 1 0 a p p e a r b e t w e e n 2 . 0 a n d 2 , 5 6 . I t i s p o s s i b l e t h a t t h e C 2 c a r b o n a n d H 2 p r o t o n o f t h e n o r b o r n e n o y l c o m p l e x I V . a r e e x p e r i e n c i n g p r e f e r e n t i a l d e s h i e l d i n g f r o m t h e p h e n y l g r o u p s o f P P h ^ . - 3 3 0 -M o d e l s i n d i c a t e t h a t t h e r e i s p r o b a b l y l i t t l e f r e e r o t a t i o n o f t h e Ru-C0R-; ; b o n d a n d H 2 a n d a r e i n t h e r e g i o n m o s t l i k e l y t o b e d e -s h i e l d e d . T h e a t o m may a l s o b e e x p e r i e n c i n g s l i g h t s h i e l d i n g e f f e c t s f r o m t h e P P h ^ g r o u p s b e c a u s e o f g e o m e t r i c c o n s t r a i n t s . T r i p h e n y l p h o s p h i n e u s u a l l y e x h i b i t s f o u r r e s o n a n c e s i n t h e 1 3 1 C{\" H } - n . m . r . s p e c t r a b e t w e e n 1 2 8 a n d 1 3 8 p p m ' w h i c h , f o r m o n o p h o s p h i n e c o m p l e x e s , a r e a s s i g n e d b y t h e m a g n i t u d e o f t h e i r c o u p l i n g s t o t h e p h o s p h o r u s n u c l e u s 2 0 2 ( J p C ( - | ) ~ 4-0 H z ; J p C ( 2 D ) ~ 1 5 H z ? Jpc(3 5 ) ~ 8 H z ; ^PC(4.)~ ^ * W i t h m o r e t h a n o n e c o o r d i n a t e d p h o s p h i n e h o w e v e r , t h e c o u p l i n g s a r e g o v e r n e d b y | j p ^ + J p t ( _ , | 5 5 s o t h a t i f Jp^ , a n d J p t Q a r e o f a p p r o x i m a t e l y e q u a l m a g n i t u d e b u t h a v e o p p o s i t e s i g n s , m e a s u r e d J v a l u e s w i l l b e s i g n i f i c a n t l y r e d u c e d . T h e s m a l l v a l u e s o b s e r v e d i n t h i s c o m p o u n d (<5 H z ) s u g g e s t t h a t t h i s may b e t h e c a s e h e r e ( F i g u r e 7 . 1 1 a ) ' , T h e p r o d u c t o f t h e h y d r i d o ( o l e f i n ) c o m p l e x p l u s CO r e a c t i o n p r e s u m a b l y p r o c e e d s v i a s e q u e n t i a l i n s e r t i o n s o f o l e f i n a n d c a r b o n m o n o x i d e i n t o t h e r u t h e n i u m h y d r i d e ' b o n d . - S u c h r e a c t i v i t y i s f u n d -a m e n t a l i n c a t a l y t i c h y d r o f o r m y l a t i o n r e a c t i o n s , a n d s e v e r a l i s o l a b l e r u t h e n i u m - a c y l c o m p o u n d s a r e k n o w n . T h e k i n e t i c l a b i l i t y o f t h e r u t h e n i u m - c a r b o n o - b o n d s l i m i t s t h e i s o l a t i o n o f a l k y l p r e c u r s o r s 2 1 2 , b u t t h e s e s eem t o b e s t a b i l i z e d b y c o o r d i n a t e d c a r b o n m o n o x i d e . S b r a n a a n d c o w o r k e r s 2 1 3 h a v e g e n e r a t e d r u t h e n i u m - a l k y l s p e c i e s i n s i t u b y r e a c t i n g [ R u C l d ^ - C ^ H ^ ) ( C O ) ^ ^ w i t h a l k y n e s o r h y d r o g e n . S u b s e q u e n t CO i n s e r t i o n l e a d s t o f o r m a t i o n o f m o n o - o r d i - h a p t o - a c y l c o m p l e x e s . 2 1 4 2.-1 5 . \u2022 -R o p e r a n d W r i g h t ' ' . h ^ v e - \" - r e c e n t l y i - p r e p a r e d a - - s e r i e s o f c o m p l e x e s R u X ( C 0 ) ( p . - t o l y l ) ( P P h 3 ) 2 , X - C I , B r , I , b y r e a c t i o n o f H R u C l ( C O ) ( P P h ^ w i t h H g ( p _ - t o l y l ) \u201e a n d s u b s e q u e n t m e t a t h e s e s , . T h e a - a r y l c o m p l e x e s - 3 3 1 -r e a c t r e v e r s i b l y w i t h o n l y o n e e q u i v a l e n t o f CO t o g i v e e q u i l i b r i u m m i x t u r e s o f d i c a r b o n y l s a n d m o n o c a r b o n y l a c y l s . T h e a c y l f o r m i s P \" R I . : R U . \u2022P \u2022co CO R-x-P :RUT I p -CO \u2022co x^ oc-p I : R U : I p \u2022 0 I - C \u2014 R V V I P = P P h y R = p - t o l ; X = C I , B r , I , V I I f a v o r e d f o r X = I ' > B r > C L , a n d V I I w i t h X = I h a s b e e n d e f i n e d c r y s t a l l o g r a p h i c a l l y . I t i s n o t c l e a r w h y V I I d o e s n o t a d d f u r t h e r C O , t o g i v e a s p e c i e s a n a l o g o u s . t o I I I ; t h e n a t u r e o f R i s c l e a r l y c r i t i c a l a n d s u c k i n f o r m a t i o n i s i m p o r t a n t s i n c e t h e l i f e t i m e s o f r | 2 - a c y l i n t e r m e d i a t e s a r e p r o b a b l y a k e y f e a t u r e o f s e v e r a l c a t a l y t i c p r o c e s s e s . M a w b y a n d c o w o r k e r s 2 1 0 ' 2 1 6 ' 2 1 7 h a v e u s e d a m o r e b a s i c a l k y l s y s t e m (R ' = C H ^ ) w i t h m o r e b a s i c a n c i l l a r y , l i g a n d s (EMe^Ph; E = P , A s ) t o s t u d y t h e m e c h a n i s m o f CO i n s e r t i o n . #:co .CO OC R u -y i -Me -1 0 0 V X \"\u2022^Ru-Me L V I I I ( X = C I , B r , I ; L - = E M e 2 P h ) L ' - \u2022 R u -'I L I X < Me X - ' R u -x Me - 3 3 2 -T h e a c e t y l l i g a n d h a s b o t h l a r g e r t r a n s d i r e c t i n g a n d t r a n s l a b i l i z i n g e f f e c t s t h a n C O , a n d i s o m e r I X w a s i n e v e r y c a s e t h e k i n e t i c p r o d u c t , a l t h o u g h X i s t h e r m o d y n a m i c a l l y f a v o r e d . . I n t h e p r e s e n t w o r k , a n i s o m e r c o r r e s p o n d i n g t o X ( L 1 = CO) i s t h e o n l y p r o d u c t i s o l a t e d o r d e t e c t e d . I t i s d i f f i c u l t t o c o m p a r e t h e r n o r b o r n a d i e n e s y s t e m d i r e c t l y w i t h t h a t o f M a w b y , b u t i t s e e m s l i k e l y t h a t t h e same c h e m i s t r y p e r t a i n s f o r b o t h . T h e r e a c t i o n o f H R u C l ( n b d ) ( P P h ^ ) 2 w i t h i s l e s s s t r a i g h t f o r w a r d , b u t t h e o v e r a l l t r a n s f o r m a t i o n c a n b e d e s c r i b e d b y e q u a t i o n 7 . 2 . H R u C l ( n b d ) ( P P h 3 ) 2 + 2 | H g 1*\u00bb \u00a3 [ H g R u C K P P ^ ) 2 ] 2 + n o r b o r n a n e ( 7 . 2 ) R a p i d u p t a k e o f - 2 H 2 . p e r R u i s c o n s i s t e n t w i t h f a s t i n i t i a l h y d r o g e n a t i o n o f t h e n o r b o r n a d i e n e l i g a n d t o n o r b o r n a n e , w h i c h m e a n s t h a t t h e i n i t i a l r e l a t i v e l y h i g h y i e l d f o r m a t i o n o f H R u C l ^ P h ^ ) ^ u n d e r t h e c o n d i t i o n s d e s c r i b e d m u s t b e a t t r i b u t e d t o a f a c i l e d i s p r o -p o r t i o n a t i o n o f a h y d r i d o b i s ( p h o s p h i n e ) s p e c i e s . S u c h a r e a c t i o n i s p r o b a b l y r e s p o n s i b l e f o r t h e p r e s e n c e o f t w o v i s i b l e a b s o r b a n c e m a x i m a i n t h e m o r e d i l u t e s o l u t i o n s ( F i g u r e 7 , 3 b ) , s i n c e t h e o n e max imum i n t h e r e g i o n o f 5 2 0 nm c o u l d w e l l b e a t t r i b u t e d t o t h e H R u C l ( P P h 3 ) 3 s p e c i e s . . S i m i l a r l y , t h e r a t e o f u p t a k e o f t h e f i n a l h a l f m o l e o f H 2 i s l i k e l y t o b e l i m i t e d b y t h e r a t e o f a c o n p r o -p o r t i o n a t i o n s t e p ( s e e b e l o w ) . T h i s b e h a v i o r i s i n m a r k e d c o n t r a s t t o t h e a p p a r e n t s t a b i l i t y o f t h e A B C D s p e c i e s d e s c r i b e d i n S e c t i o n 5 . 4 a n d may b e u s e d a s w e a k e v i d e n c e a g a i n s t f o r m u l a t i n g t h e A B C D s p e c i e s a s [ H R u C l ( P P h \u201e ) 2 L ; t h i s i s a t e n u o u s c o n c l u s i o n , h o w e v e r , b e c a u s e t h e -333-a p p a r e n t d i s p r o p o r t i o n a t i o n may s i m p l y r e f l e c t t h e i n s t a b i l i t y o f a m o n o m e r i c b i s ( p h o s p h i n e ) s p e c i e s . T h e c o m p l e t e h o m o g e n e i t y o f t h e r e a c t i o n i n h y d r o c a r b o n s o l v e n t s a f t e r - 20 m i n , a n d t h e f i n a l g e n e r a t i o n o f . [ H 2 R u C l ( P P h 3 ) 2 ] 2 f r o m a t r i s ( p h o s p h i n e ) s p e c i e s . , , i n d i c a t e t h e p r e s e n c e o f a s o l u b l e p h o s p h i n e d e f i c i e n t r u t h e n i u m c o m p l e x . I n l i g a n d d e f i c i e n t s y s t e m s , c e r t a i n p l a t i n u m m e t a l s ( e . g . , . R h , I r , R u ) a r e c a p a b l e o f u - b o n d l n g t o a v a i ' l ^ b l e - a r e n e s \u2022 , 2 ' 1 8 - \u2022\u2022 2 ?\u2022 ; artd r \" e x a m p l e s - . - e x i s t i n w h i c h ' t h e p h e n y l g r o u p o f a r y l p h o s p h i n e l i g a n d s ' \u2022be.cpme - \u2022 eo .p r . d ina t e d - 7 2 ' 1 8 0 ' 1 9 1 > 2 2 5 \" 2 2 7 X I X I I T h e P { h} c h e m i c a l s h i f t o f t h e a r e n e - b o u n d P P h ^ i n c o m p l e x X I (-5.77 ppm) i s c l o s e t o t h a t f o u n d f o r f r e e P P h ^ (-6.34- p p m ) , u n d e r i d e n t i c a l c o n d i t i o n s . i n a c e t o n e - d ^ a t 25 \u00b0 C I n t h e p r e s e n t 31 s t u d y , t h e r e w a s n o e v i d e n c e f o r a n y P s i g n a l s i n t h i s r e g i o n , e i t h e r a t 30\u00b0C o r a t -60\u00b0C, i m p l y i n g t h e a b s e n c e o f a n y s u c h 7T - b o u n d 31 1 P P h ^ l i g a n d . I n f a c t , t h e P { H } - n . m . r . s p e c t r a g a v e n o e v i d e n c e f o r a n y m o n o p h o s p h i n e s p e c i e s t o c o m p l e m e n t t h e t r i s ( p h o s p h i n e ) h y d r i d e , 31 H R ' u C l ( P P h 0 ) 0 . T h e c o m p o u n d r e s p o n s i b l e f o r t h e o b s c u r e d P r e s o n a n c e 3 3 a t 70.64 ppm i s t h e m o s t r e a s o n a b l e c a n d i d a t e f o r t h i s - c o m p l e m e n t a r y s p e c i e s b u t t h e a b s e n c e o f a n y e v i d e n c e f o r i t a t l o w e r t e m p e r a t u r e s , a n d t h e 1 i n a b i l i t y t o o b s e r v e t h e c o r r e s p o n d i n g h y d r i d e r e s o n a n c e b y H - n . m . r . - 3 3 4 -( J = 31 H z ) a t 2 5 \u00b0 C , s u g g e s t t h a t t h e c o m p o u n d i s n o t a l w a y s p r e s e n t , P H a t l e a s t i n s u f f i c i e n t ; , c o n c e n t r a t i o n s t o a c c o u n t f o r t h e d i s p r o p o r t -i o n a t i o n . T h i s i s p a r t i c u l a r l y d i f f i c u l t t o r a t i o n a l i z e i n v i e w o f t h e p a u c i t y o f a v a i l a b l e l i g a n d s . E v e n w h e n t h e o n l y o r g a n i c r e s o n a n c e s o b s e r v e d ( e x c l u d i n g t h o s e o f P P h ^ ) w e r e t h o s e o f n o r b o r n a n e , t h e p r e s e n c e o f H R u C l f P P h ^ . ) ^ , w h i c h e v e n t u a l l y f o r m e d o n l y [ H g R u C l t P P h ^ ) ^ ] ^ f i m p l i e d t h e p r e s e n c e o f t h e \" l i g a n d d e f i c i e n t s p e c i e s \" . One p o s s i b l e s o u r c e o f s t a b i l i z a t i o n may i n v o l v e t h e a r o m a t i c s o l v e n t s y s t e m s t h e m s e l v e s . . B e n z e n e c o m p l e x e s o f r u t h e n i u m a r e a l s o w e l l k n o w n , b u t n o r m a l l y a r e p r e p a r e d f r o m h e x a d i e n e p r e c u r s o r s . F u r t h e r s p e c u l a t i o n i s n o t j u s t i f i e d i n t h e a b s e n c e o f a d d i t i o n a l i n f o r m a t i o n . - 3 3 5 -C H A P T E R 8 . G E N E R A L SUMMARY AND RECOMMENDATIONS FOR F U T U R E WORK. A n i m p o r t a n t c o n t r i b u t i o n o f t h i s w o r k i s t h e d e f i n i t i v e r e - i n v e s t i g a t i o n o f some p r e v i o u s l y s t u d i e d r u t h e n i u m p h o s p h i n e . \/ d i h y d r o g e n s o l u t i o n r e a c t i o n s a n d t h e r e c h a r a c t e r i z a t i o n o f t h e c o m p l e x e s i n v o l v e d . T h i s a l s o l e d t o a r e - e v a l u a t i o n o f t h e t h e r m o d y n a m i c s t a b i l i t y o f c e r t a i n l i g a n d a r r a n g e m e n t s a r o u n d d i n u c l e a r r u t h e n i u m s y s t e m s . S p e c t r o s c o p i c s t u d i e s i n t o l u e n e a n d DMA o n t h e i m p o r t a n t c a t a l y s t p r e c u r s o r c o m p o u n d s , R u C l g C P P h ^ ) ^ a n d R u B r p J P P h . ^ ) ^ , s h o w e d t h a t t h e n u c l e a r i t y o f t h e t h e r m o d y n a m i c a l l y f a v o r e d b i s ( p h o s p h i n e ) p r o d u c t s , w h e r e t h e y c o u l d b e d e t e r m i n e d u n a m b i g u o u s l y , w e r e d i m e r i c . S u c h b e h a v i o r w a s p r e v i o u s l y k n o w n i n t o l u e n e , b u t t h e s o l u t i o n b e h a v i o r i n DMA w a s u n e x p e c t e d . I n t h i s l a t t e r s o l v e n t , t h e b i s ( p h o s p h i n e ) s p e c i e s e x i s t s a s t h e t r i p l y - c h l o r o b r i d g e d d i m e r , R u 0 C l ( D M A ) ( P P h Q ) . , c o n t a i n i n g 2 4 J 4 o n e DMA p e r u n i t ( I , L = D M A ) . T h i s s o l v e n t m o l e c u l e i s e a s i l y d i s p l a c e d b y c h l o r i d e t o g i v e t h e a n a l o g o u s a n i o n i c s p e c i e s , R u 0 C l c ( P P h \u201e ) ( I , L = C l ) . T h e t r i - u - c h l o r o a r r a n g e m e n t h a s b e e n ( I ) -336-o b s e r v e d i n o t h e r r u t h e n i u m s y s t e m s , i n some c a s e s p r e v i o u s l y u n r e c o g -n i z e d a s s u c h ; i t s a p p a r e n t - s t a b i l i t y p r e s u m a b l y a r i s e s f r o m t h e p r o p e n s i t y o f r u t h e n i u m ( l l ) t o b e c o m e s i x - c o o r d i n a t e . W i t h t h e c o r r e s p o n d i n g R u B r g C P P h ^ ) ^ s y s t e m i n D M A , h o w e v e r , t h e n u c l e a r i t y o f t h e b i s ( p h o s p h i n e ) s p e c i e s w a s n o t d e f i n e d . One p o s s i b l e e x t e n s i o n o f t h e p r e s e n t w o r k w o u l d b e t o c o n s i d e r t h e s o l u t i o n b e h a v i o r o f t h i s s p e c i e s a n d i t s r e a c t i v i t y t o w a r d - i n D M A . A w e a k e r b o n d e d b r o m o - b r i d g e c o u l d l e a d t o a m o n o n u c l e a r e o o r d i n a t l v ' e l y u n s a t u r a t e d s p e c i e s w i t h c o n s i d e r a b l y h i g h e r r e a c t i v i t y , i n c l u d i n g c a t a l y t i c a c t i v i t y , t h a n t h e c h l o r o s y s t e m . A m o r e d e t a i l e d i n v e s t i g a t i o n o f t h e r e a c t i o n b e t w e e n R u C l ^ P P h ^ ) ^ a n d i n DMA c o n t a i n i n g c h l o r i d e l e d t o s e v e r a l l a t e r a l s t u d i e s a n d i n t e r e s t i n g f i n d i n g s . O f p a r t i c u l a r i n t e r e s t i s t h e r e f o r m u l a t i o n o f a h y d r i d o - b i s ( p h o s p h i n e ) s p e c i e s p r e v i o u s l y d e s c r i b e d a s [ H R u C l C P P h ^ ) ( C h a p t e r 4 ) 1 2 . T h e new f o r m u l a t i o n a s [ ' H g R u C ^ P P h ^ ) ^ ] ^ m a k e s t h i s c o m p l e x t h e f i r s t w e l l - c h a r a c t e r i z e d h y d r i d o c o m p l e x o f r u t h e n i u m i n t h e f o r m a l o x i d a t i o n s t a t e o f +3. O t h e r h y d r i d o - r u t h e n i u m ( l I I ) s p e c i e s h a v e b e e n o b s e r v e d p r e v i o u s l y , b u t t h e s e w e r e n e v e r i s o l a t e d i n a p u r e s t a t e 1 2 . T h e c r y s t a l s t r u c t u r e s h o w s a d i s t o r t e d m o l e c u l a r a r r a n g e m e n t w i t h t w o r u t h e n i u m a t o m s j o i n e d b y a m e t a l . - m e t a l b o n d ( 2 . 8 0 S) . A l t h o u g h t h e c o m p l e x i s h i g h l y f l u x i o n a l i n s o l u t i o n , t h e n . m . r . s p e c t r a i n t h e s l o w e x c h a n g e r e g i o n , , s h o w i n g f o u r i n e q u i v a l e n t p h o s p h i n e s a n d t h r e e t y p e s o f h y d r i d e s , p r o v e t h a t t h e a s y m m e t r y p e r s i s t s a t l o w t e m p e r a t u r e s i n s o l u t i o n . T h e e x i s t e n c e o f t h e m e t a l - m e t a l b o n d i s 31 a l s o r e f l e c t e d i n t h e o b s e r v e d s p i n - c o u p l i n g b e t w e e n P n u c l e i o n a d j a c e n t r u t h e n i u m c e n t e r s . T h e k i n e t i c d a t a o f t h e r e a c t i o n b e t w e e n [ H Q R u C l ( P t o l ^ ) 9 ] 9 a n d P t o l q t o g i v e H R u C l ( P t o l ^ ) r w i t h e l i m i n a t i o n o f H 2 - 3 3 7 -s u g g e s t t h a t t h e t e t r a h y d r i d e e x i s t s i n e q u i l i b r i u m w i t h a r e a c t i v e d i h y d r i d e d i m e r , . [ H R u C l ( P t o l 3 ) g ] g , a n d t h e f o r m e r may b e c o n s i d e r e d t o b e a d i h y d r o g e n a d d u c t o f t h e l a t t e r . I n t e r e s t i n g l y , a l t h o u g h t h e a n a l o g o u s t r i p h e n y l p h o s p h i n e . c o m p l e x [ H g R u C l ( P P h 3 ) g ] g a p p a r e n t l y r e a c t s 3 10 t i m e s f a s t e r w i t h H g t h a n w i t h P P h ^ , t h e p r o d u c t o f t h e l a t t e r r e a c t i o n , H R u C l C P P h ^ ) , i s t h e r m o d y n a m i c a l l y m o r e s t a b l e a n d i n e s s e n t i a l l y c o m p e t i t i v e e x p e r i m e n t s f o r m s p r e f e r e n t i a l l y . T h e p r e s e n t w o r k i n d i c a t e s t h a t t h e s o l u t i o n r e a c t i o n o f R u C l g C P P h ^ ) 3 w i t h \u2022 - H g i n t h e p r e s e n c e o f e x c e s s P P h ^ - t o , f o r m H R u C l t P P h ^ g o e s b y w a y o f t h e . m o n o m e ' r i c . b i s ( p h o s p h i n e ) . ' s p e c i e s , R u C l ^ P P h ^ ) g , i n a c c o r d w i t h e a r l i e r f i n d i n g s 6 . H o w e v e r , i n t h e p r e s e n c e o f e x c e s s c h l o r i d e , t h e p r e c u r s o r e x i s t s a s t h e c o o r d i n a t i v e l y s a t u r a t e d c o m p l e x , R u _ C l _ ( P P h J . , a n d a k i n e t i c i n v e s t i g a t i o n i n d i c a t e s t h a t t h i s d i m e r 2 5 3 4 ' s p e c i e s r e a c t s d i r e c t l y w i t h H g ? t h i s g e n e r a t e s a l o n g - l i v e d i n t e r m e d i a t e t h a t e v e n t u a l l y d e c a y s t o f o r m t h e e x p e c t e d p r o d u c t , H R u C l ( P P h 3 ) 3 \u00bb 31 B a s e d m a i n l y o n P - n . m . r . e x p e r i m e n t s a n d t h e s i m i l a r i t y o f t h e i n i t i a l s o l u t i o n b e h a v i o r o f t h e R u 0 C l . ( L ) ( P P h J . s p e c i e s (L \u2022= DMA, C I ) i n t h e 2 4 3 4 a b s e n c e o f p h o s p h i n e , t h e i n t e r m e d i a t e i s b e l i e v e d t o b e H Q R u 0 C l _ ( P P h _ ) . , 3 2 3 3 4 i n e s s e n c e t h e H C 1 a d d u c t o f [ H R u C l t P P h ^ ) g ] g . T h e 3 1 P - 3 1 P c o u p l i n g p a t t e r n f o r t h i s s p e c i e s ( C h a p t e r 5) i s c o n s i s t e n t w i t h t h e p r e s e n c e o f a R u ( l l l ) - R u ( l l l ) d i m e r u n i t a n d t h e k i n e t i c d a t a f o r t h e H g r e a c t i o n a r e c o n s i s t e n t w i t h . t h e o v e r a l l s c h e m e f o r t h e t r i s ( p h o s p h i n e ) s y s t e m : k 1 R u \u201e C l c ( P P h J \" + H _ w H R u 0 G l , ( P P h J \" + H C 1 ( 8 . 1 ) 2 5 3 4 2 . 4 3 4 -1 H R u 0 C l . ( P P h J ' + H \u201e H , R u 0 C l Q ( P P h J , + C l \" ( 8 . 2 ) 2 4 3 4 2 A> <\u2022 i i k 2 H 3 R U g C l 3 ( P P h 3 ) ^ H g R U g C l g t P P h ^ + H C 1 (8.3) k - - 2 - 3 3 8 -k P P h H 2 R u 2 C l 2 ( P P h 3 ) ^ + P P h 3 J > *> J 2 H R u C l ( P P h 3 ) 3 (8.1,} R e a c t i o n s 8 . 1 a n d 8 . 2 h a v e b e e n d i s c u s s e d i n t e r m s o f a s e r i e s o f i n t r a m o l e c u l a r r e a r r a n g e m e n t s c o n c o m i t a n t w i t h a d d i t i o n \u201e ( C h a p t e r 5 ) . I n t h e a b s e n c e o f a d d e d p h o s p h i n e u n d e r c o r r e s p o n d i n g c o n d i t i o n s i n D M A , a s i m i l a r s c h e m e c a n b e e m p l o y e d t o r a t i o n a l i z e t h e o b s e r v e d r e a c t i v i t y t o w a r d o f t h e b i s ( p h o s p h i n e ) s p e c i e s ( I , L = C l , D M A ) : k ' k 1 R u _ C l , ( P P h J . ( L ) + H _ W l H R u 0 C l _ ( P P h _ ) . ( L ) + H C l ( 8 . 5 ) -1 H R u 2 C l 3 ( P P h 3 ) ^ ( L ) + H 2 H 3 R u 2 C l 3 ( P P h 3 ) i + L ( 8 . 6 ) k 2 H ' 3 R u 2 C l 3 ( P P h 3 ) < 4 w H 2 R u 2 C l 2 ( P P h 3 ) ^ + H C l ( 8 . 3 ) k - 2 k ' k 3 H 2 R u 2 C 1 2 ( P P h 3 ) 4 + H 2 ^ k H j 4 R u 2 C l 2 ( P P h 3 ) \/ i ( 8 . 7 ) D e s p i t e t h e c o n s i s t e n c y o f t h e d a t a a n d a r g u m e n t s p r e s e n t e d I n C h a p t e r 5 , t h e t e n t a t i v e c h a r a c t e r i z a t i o n o f t h e A B C D s p e c i e s a s H _ R u 0 C l _ ( P P h Q ) , a n d i t s a s s i g n m e n t a s t h e o v e r a l l r e a c t i o n i n t e r m e d i a t e s h o u l d b e t e s t e d m o r e d i r e c t l y . R e a c t i o n b e t w e e n [ H 2 R u C l ( P t o l 3 ) 2 ] 2 a n d D M A * H C l s e e m s p r o m i s i n g a s a p o s s i b l e s y n t h e t i c r o u t e i n t o t h e s e s p e c i e s . H o w e v e r , i n v i e w o f t h e o v e r a l l t e n d e n c y o f [ H 2 R u C l ( P P h 3 ) 2 J 2 t o r e a c t w i t h e x c e s s H C l t o f o r m R u 0 C l c ; ( P P h Q ) . w i t h l i b e r a t i o n o f h y d r o g e n ( C h a p t e r - 4 ) , c o n d i t i o n s m u s t b e made s o t h a t i n t r o d u c t i o n o f t h e a c i d t o t h e t e t r a h y d r i d e s p e c i e s i s s l o w , a n d t h e l o c a l r u t h e n i u m c o n c e n t r a t i o n i s a l w a y s g r e a t e r t h a n t h a t o f H C l . L o w t e m p e r a t u r e s a n d \/ o r c h o i c e o f a s o l v e n t i n w h i c h t h e H C l s o u r c e i s p o o r l y s o l u b l e may a i d i n t h e s e -339-a t t e m p t s . A l t e r n a t i v e l y , s t o i c h i o m e t r i c a d d i t i o n o f o t h e r c h l o r i n a t i n g a g e n t s ( e . g . , CC1.) may b e u s e f u l f o r t h i s r e q u i r e d t r a n s f o r m a t i o n . 4 A n o t h e r p o s s i b l y c l e a n e r r o u t e may i n v o l v e a d d i t i o n o f a s t o i c h i o m e t r i c e q u i m o l a r c h l o r i d e - h y d r o c h l o r i d e m i x t u r e t o t h e k n o w n c o m p l e x , [ H R u ( n 6 - C 6 H ^ ) ( P P h 3 ) 2 ] f P F 6 ] 2 2 5 i n p o l a r s o l v e n t s s u c h a s a l c o h o l s . T h o u g h n o s y n t h e t i c d e t a i l s a r e g i v e n , t h e r e a c t i o n o f t h e c o r r e s p o n d i n g [ H R u ( n 6 - C 6 H 5 P P h 2 ) ( P P h 3 ) 2 ] [ P F 6 ] c o m p l e x w i t h L i C l t o f o r m H R u C l ( P P h 3 ) 3 i s k n o w n 2 2 6 , a n d a s i m i l a r r e a c t i v i t y w i t h t h e b e n z e n e b i s ( p h o s p h i n e ) p r e c u r s o r s e e m s v i a b l e , - . S u c h a m e t h o d t o f o r m H 3 R u 2 C l 3 ( P P h 3 ) ^ w o u l d a p p e a r t o h a v e a s y n t h e t i c a d v a n t a g e o v e r m e t h o d s u s i n g (( [ H 2 R u C l ( P P h 3 ) 2 ] 2 a s t h e p r e c u r s o r i n t h a t a n y n e u t r a l H 3 R u 2 C l 3 ( P P h 3 ) ^ c o m p l e x s h o u l d p r e c i p i t a t e c l e a n l y f r o m t h e a l c o h o l r e a c t i o n m i x t u r e s . H o w e v e r , c o m p l i c a t i o n s c o u l d a r i s e . f r o m t h e i n i t i a l f o r m a t i o n o f a m o n o m e r i c \" H R u C l ( P P h 3 ) 3 \" s p e c i e s t h a t may d i s p r o p o r t i o n a t e ( C h a p t e r 7 ) . I f t h i s o c c u r s , , l e s s p o l a r s o l v e n t s ( e . g . , C H 2C1 2 o r T H F ) may b e u s e f u l i n p r o m o t i n g a t h e r m o d y n a m i c a l l y c o n t r o l l e d r e a c t i o n . T h e r e a c t i o n s b e t w e e n H R u C l ( P P h 3 ) 3 a n d m a l e i c o r f u m a r i c a c i d s d o n o t y i e l d o r t h o m e t a l l a t e d c o m p l e x e s , a s p r e v i o u s l y r e p o r t e d 1 3 , b u t g i v e s u c c i n i c a c i d d e r i v a t i v e s . E x t e n s i o n s o f t h i s f i n d i n g l e d t o a n e w m e t h o d o f p r e p a r i n g c a r b o x y l a t o c o m p l e x e s b a s e d o n p r e s u m e d , b u t n o t 31 i d e n t i f i e d , a l k y l i n t e r m e d i a t e s . P r e l i m i n a r y P - n , m . r . s t u d i e s o n t h e h y d r i d e \/ u n s a t u r a t e d a c i d s y s t e m s w e r e h a m p e r e d b y t h e p o o r s o l u b i l i t y o f t h e t r i p h e n y l p h o s p h i n e p r e c u r s o r ; f u t u r e u s e o f t h e e x t r e m e l y s o l u b l e P t o l 3 a n a l o g u e , H R u C l ( P t o l 3 ) 3 > s h o u l d a l l o w f o r m o r e d i r e c t i n v e s t i g a t i o n s o f h y d r i d e - o l e f i n i n t e r a c t i o n s . B o t h t h e b i s - a n d t r i s ( p h o s p h i n e ) c h l o r o c a r b o x y l a t o s p e c i e s r e a c t w i t h H 2 . i n t o l u e n e w i t h o u t a d d e d b a s e , b u t t h e r e a c t i o n s i n v o l v e p r e f e r e n t i a l r e l e a s e o f H C l r a t h e r t h a n t h e h o p e d - f o r o r g a n i c a c i d , - 3 4 0 -R C 0 0 H . One f a c t o r - i s a l m o s t c e r t a i n l y t h e b i d e n t a t e mode o f c o o r d i n a t i o n a v a i l a b l e f o r c a r b o x y l a t e . . . T h e n o n - r e a c t i v i t y o f R u C O g C R ) ^ ( P P h ^ ) ^ t o w a r d may b e r a t i o n a l i z e d s i m i l a r l y i n t e r m s o f a n u n f a v o r a b l e i n i t i a l e q u i l i b r i u m ( e q u a t i o n 8 . 8 ) . T h e f i n d i n g t h a t t h e m i x e d h a l o -P P h 3 . . - - ... P P h ^ J>o\u201e | ^ . 0 X , . .... DMA . 0,,, | v *0 . R \" C v ^ R ' d ' ' * > G - R + ' H 9 ^ - ' R-c' . R u : G - R ' + ; R C 0 0 H ( 8 . 8 ) X 0 ^ | ^ 0 X 0 * | ^ O ^ . P P h 3 P P h 3 ,. I l l c a r b o x y l a t o b i s ( p h o s p h i n e ) s p e c i e s , R u X ^ O ^ C R ) ( P P h 3 ) g , r e a c t w i t h h y d r o g e n t o g i v e m e t a l - m e t a l b o n d e d ' . p r o d u c t s c o n t a i n i n g o n l y b r i d g i n g h a l i d e s i s r a t h e r s u r p r i s i n g . , c o n s i d e r i n g t h e k n o w n p r o p e n s i t y o f t h e c a r b o x y l a t o l i g a n d t o b r i d g e . R e a c t i o n o f [ H R u ( r ) \u00b0 - C ^ H ^ ) ( P P h ^ ^ \"f w i t h c a r b o x y l a t e s a l t s c o u l d p r o v i d e a n a v e n u e i n t o c a r b o x y l a t o h y d r i d o -b i s ( p h o s p h i n e ) c h e m i s t r y . A t t e m p t s t o g e n e r a t e p o t e n t i a l l y o b s e r v a b l e [ H R u C l ( P P h 3 ) ^ ] ^ c o m p l e x l e d t o a n i n v e s t i g a t i o n o f t h e c h e m i s t r y o f H R u C l ( n b d ) ( P P h 3 ) g . R e a c t i o n w i t h p r o d u c e d t h e [ H g R u C l t P P h ^ ) ^ ] ^ c o m p l e x , b u t . t h e p a t h w a y i n v o l v e d s u c c e s s i v e d i s p r o p o r t i o n a t i o n ( t o g i v e H R u C l ( P P h 3 ) ^ ) a n d c o n p r o p o r t i o n a t i o n r e a c t i o n s a n d s h o w e d n o e v i d e n c e f o r a n y [ H R u C ^ P P h ^ g J ^ . S u c h d i s p r o p o r t i o n a t i o n i s p r o b a b l y d u e t o t h e s t a b i l i t y o f t h e t r i s ( p h o s p h i n e ) h y d r i d e . N e v e r t h e l e s s , t h e a b i l i t y t o g e n e r a t e u n s a t u r a t e d , r e l a t i v e l y \" n a k e d \" , , r u t h e n i u m s p e c i e s b y h y d r o g e n a t i n g a n u n s a t u r a t e d h y d r o c a r b o n l i g a n d w a s d e m o n s t r a t e d , a n d e x t e n s i o n s o f t h i s may p r o v i d e c o n s i d e r a b l e o p p o r t u n i t y f o r n e w c h e m i s t r y . V e r y r e c e n t l y , C h a u d r e t a n d c o - w o r k e r s 2 3 2 h a v e b e g u n e x p l o r i n g t h e r e a c t i v i t y o f R u ( c y c l o o c t a t e t f a e n e ) ( c y c l o o c t a d i e n e ) a n d i t s : ' d i p h d s p h i n e . d e r i v a t i v e s , - 3 4 1 -u n d e r h y d r o g e n a t i o n c o n d i t i o n s , a n d h a v e g e n e r a t e d p o l y h y d r i d e c l u s t e r c o m p l e x e s , s i m i l a r t o t h o s e d e s c r i b e d b y H a l p e r n a n d c o - w o r k e r s f o r t h e b i s ( t r i p h e n y l p h o s p h i n e ) s y s t e m s 2 3 3 . A p r e c u r s o r c o m p l e x s u c h a s R u ( a l l y l ) 2 ( P P h 3 ) 2 2 3 \/ 2 3 t * s h o u l d s h o w s i m i l a r r e a c t i v i t y : R u ( a l l y l ) 0 ( P P h \u201e ) 0 + ( n+2) H R u ( H 0 ) ( P P h _ ) 0 + 2 p r o p a n e ( 8 . 9 ) 2 3 2 2 2 n 3 2 m *r. sr A d d i t i o n a l l y , t h e c i s - d i s p o s i t i o n o f t h e p h o s p h i n e s i n t h i s a l l y l c o m p l e x ( $ P R u P =. 1 0 9 . 9 ) 2 3 : 5 s u g g e s t s . t h a t \" - s u b s t i t u t l o n w i t h a s i n g l e b i d e n t a t e p h o s p h i n e o r o t h e r l i g a n d s h o u l d b e f a c i l e , a n d a c o n s i d e r a b l e r a n g e o f l o w - v a l e n t r u t h e n i u m c o m p l e x e s o f c a t a l y t i c p o t e n t i a l c o u l d b e c o m e a v a i l a b l e . T h e r e a c t i o n b e t w e e n H R u C l ( n b d ) ( P P h ^ ) 2 a n d c a r b o n m o n o x i d e w a s p a r t i c u l a r l y c l e a n , a n d l e d t o f o r m a t i o n o f a n o r b o r n e n o y l d e r i v a t i v e , p r e s u m a b l y b y t h e d o u b l e i n s e r t i o n o f o l e f i n a n d CO i n t o t h e R u - H b o n d . T h e f a c t o r s w h i c h g o v e r n m i g r a t o r y i n s e r t i o n r e a c t i o n s , p a r t i c u l a r y o f o l e f i n i n t o m e t a l - h y d r i d e b o n d s , a r e n o t f u l l y u n d e r s t o o d , a l t h o u g h i n t h i s r u t h e n i u m s y s t e m , i n i t i a l c o o r d i n a t i o n o f t h e s t r o n g l y T T - a c i d i c CO l i g a n d may b e r e s p o n s i b l e . . ^ o r t h e o l e f i n i n s e r t i o n . I t w o u l d b e o f i n t e r e s t t o e x t e n d t h i s r e a c t i v i t y t o t h e b r o m o a n d o t h e r m o n o a n i o n i c d e r i v a t i v e s a n d a l s o t o u s e o t h e r r e a g e n t s t o f u r t h e r i n v e s t i g a t e t h e f a c t o r s i n f l u e n c i n g t h e s e p r o c e s s e s . . U s e o f P F ^ a n d RNC a s t h e a d d e d r e a g e n t s i s s u g g e s t e d ; t h e f o r m e r h a s a i r - a c i d i t y c o m p a r a b l e t o t h a t o f CO a n d m i g h t b e e x p e c t e d t o p r o m o t e o l e f i n i n s e r t i o n r e a c t i o n s , w h i l e t h e u s e o f i s o c y a n i d e s p r o v i d e s a g r e a t e r d e g r e e o f v a r i a b i l i t y w i t h i n e l e c t r o n i c - a n d s t e r i c p a r a m e t e r s . F u r t h e r , R o p e r e t a l v 2 . 3 6 , ' h a v e s h o w n . t h a t h e a t i n g R u C l ( R ) ( C O ) ( C N R ) ( P P h ^ ) 2 (R = j j - t o l y l ) r e s u l t s i n p r e f e r e n t i a l 2 i n s e r t i o n o f t h e i s o c y a n i d e i n t o t h e R u - C b o n d t o f o r m a n n - i m i n o a c y l -34-2-c o m p l e x . T h e f a c t o r s g o v e r n i n g t h e b o n d i n g mode o f s u c h a c y l s (r\\ 2 vs. n ) a r e n o t w e l l u n d e r s t o o d i n t h e s e r u t h e n i u m s y s t e m s , a n d u s e o f a v a r i e t y o f RNC r e a g e n t s m i g h t b e i n f o r m a t i v e . -343-R E F E R E N C E S ' 1 B . R . J a m e s , \" H o m o g e n e o u s H y d r o g e n a t i o n \" , J . W i l e y a n d S o n s , N e w Y o r k , 1 9 7 3 . 2 B . R . J a m e s , . A d v . . O r g a n o m e t . C h e m , , 1 7 , 3 1 9 ( 1 9 7 9 ) . 3 B . R . J a m e s , i n G . 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