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The solution behavior and reactivity of some triarylphosphine complexes of ruthenium Dekleva, Thomas William 1983

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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. © 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,——ci»—Ru••••»»»PPh 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® (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^) , •.[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„)_ + CI" •« w Ru 0Cl c(PPh„)~ + 2 PPh, 2 $ i 2 5 3 4 3 Ru 0Cl_(PPhJ " + H„ - HRu„Cl.(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 » 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» 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 ............................................. ... •• i i T a b l e o f c o n t e n t s - • 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 )•( 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® ............ 15 2..I...4..12 DiT.y.-ehl'orotetrahydrido.tetrakis(triphenyl-phosphine)diruthenium(lll)•2DMA 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)• toluene solvate.., 18 2.1 . 4 . 1 6 Chlorohydridotri s(trir-£-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 - •. tetrahydridot.etrakis(-triaryl.phosphine)di- ; ruthenium (III)..,.....,... ,. 102 4.1' I n t r o d u c t i o n ...... ..'.•••.. •... »................................. 102 4 .2 Data . -. 107 4.2.1 Precursors'.for uptake experiments • 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„2i.4 ••. N..-.m«r.- spectroscopy 118 4.2.4.I 1H-N.m.r. . 118 4. .2 .4v2. 31P-N.,m.r. ..... . 121 4 „ 2 . 5 : Chemical r e a c t i o n s 125 A . 2 . 5 • 1 .Hydrogen c h l o r i d e 125 4 .2 .5 . i2 2,2»-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 • 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 • 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 - ' © 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^ °2 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-)^ ••• • 277 6..5-2..2 •< On- RuCl(.0oCC,H-) (PPh„) _. 283 2 o 5 3 3 6.5.3 Discussion • of-the.hydrogenation reactions 293 6.6: Discussion, of the i d e n t i t y and.reactivity with hydrogen, of the • IIRuC.'! (PPh.^) ^  complex i n benzene or toluene 295 Chapter 7- Characterization and ..-reactions, of•-. 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 „ ( 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 „ 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 <• 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 ) „ 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°C 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°C. 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„ 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°C 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 •solubility....................... 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°C 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„) ~ 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»C- 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» (C.HcC00H) '•- 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 — 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 — 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 — 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„ ( c a l c u l a t e d ) vs. A (assumed) f o r the 1 — 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„. (calculated) vs:. A (assumed) for the 2 — 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 <• 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 • of K'v ^ calculated) -vs.-*"A " (assumed) for the dissociation of RuCl^PPh^)^ in benzene 85 3 . 1 6 . Plots of K .„ (calculated)., vs.. A (assumed) for the 2 — 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°C.. . 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°C .. 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 ° 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 • 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 ° 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<p^2^ ^ e r e a c ^ 1 0 n °^ RuClgCPPh^)^ i n DMA w i t h E ^ i n t h e p r e s e n c e o f e x c e s s PPh^ 164-5.5 Dependence of, k , . w i t h [ P P h _ l f o r t h e r e a c t i o n O D S j 3 . o f RuClgCPPh^)^ in•DMA 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 P P h^ 165 5.6 Dependence o f -k ^  f o r . r e a c t i o n 5.15 on [ L i C l ] i n DMA u s i n g t h e d a t a i n r e f e r e n c e . 6 b 172 5.7 Dependence--of k ^ f o r r e a c t i o n - 5.15 on [Hg] i n DMA u s i n g - t h e d a t a i n r e f e r e n c e 6b ,172 5.8 Spectral,'^changes accompanying r e a c t i o n 5.15 u s i n g DMA d i s t i l l e d . - o n l y f rom CaH 2. 176 5.9 S p e c t r a l changes accompanying-.reaction 5.15 u s i n g r i g o r o u s l y p u r i f i e d DMA. 178 5.10 S p e c t r a l changes, accompanying r e a c t i o n 5.15 u s i n g r i g o r o u s l y p u r i f i e d . DMA wi t h . 3-85$ HgO added 186 5.11 Dependence o f k , on .[i.H0 1 f o r r e a c t i o n 5.15 w i t h obs 2 1 added PP.-h^ i n . r i g o r o u s l y p u r i f i e d DMA 191 — 1 — 1 5.12 P l o t , o f k _. vs.. [H„l f o r t h e r e a c t i o n g i v e n obs — L 2 J i n e q u a t i o n 5.15 192 5.13 V a r i a t i o n i n d e v e l o p e d i s o s b e s t i c p o i n t as a f u n c t i o n o f hydrogen p r e s s u r e . . . 194 5.14 S p e c t r a l changes accompanying t h e a d d i t i o n o f E ^ t o DMA s o l u t i o n s .of . R u G l . (DMA-) (PPh.) . c o n t a i n i n g < 4 3 4 P r o t o n Sponge^ 203 5.15 S p e c t r a l changes accompanying t h e r e a c t i o n between Ru 01 (PPh ) ~ and H i n DMA i n t h e p r e s e n c e o f 2 5 5 4 P r o t o n Sponge® t o form [ H 2 R u C l ( P P h ^ ) ? ] ? 204 S p e c t r a l c h a n g e s a t 5 0 0 nm 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 ' 0 C l r ( P P h „ ) . . a n d H „ i n DMA i n 5 3 4 t h e p r e s e n c e o f P r o t o n S p o n g e . : ; . . . . . . R a t e p l o t f o r . t h e H 0 - r e d u c t i o n o f R u 0 G l c ( P P h 0 ) " i n DMA R a t e p l o t f o r t h e H ^ - r e d u c t i o n o f R U g C l (DMAMPPh^ i n DMA R a t e p l o t s f o r t h e ^ - r e d u c t i o n o f [ R u C l 2 ( P P h ) 2 ) 2 i n t o l u e n e . R a t e p l o t f o r t h e ^ - r e d u c t i o n o f [ R u C l ^ P P h ^ ) 2 ] 2 i n t o l u e n e R a t e p l o t f o r t h e . H ^ r e d u c t i o n o f R u C l 3 ( P P h 3 ) 2 ( D M A . ) . (DMA 1) i n DMA R a t e p l o t f o r t h e H g - r e d u c t i o n o f 2 x 10 M R u G l 3 ( P P h 3 ) 2 i n DMA 31 1 T i m e a n d t e m p e r a t u r e d e p e n d e n t P { H } - n . m . r . s p e c t r a o b t a i n e d f r o m t o l u e n e - d g s o l u t i o n s r e s u l t i n g w h e n [ R u C l 2 ( P P h 3 ) 2 J 2 a n d P r o t o n S p o n g e " w e r e s h a k e n u n d e r H 2  31 1 P { H } - N . 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 C l 2 ( P P h 3 ) 2 ] 2 w a s s h a k e n i n D M A / t o l u e n e - d ? u n d e r H 2 ., 31 1 S i m u l a t e d P { H } ^ n . m . . r . . s p e c t r u m o f t h e A B C D c o m p l e x 31 P - N . m . r . s p e c t r a o f a D M A / t o l u e n e - d g s o l u t i o n c o n t a i n i n g t h e A B C D c o m p l e x 3 1 P { 1 H } - N . m . r . s p e c t r u m o f t h e D M A / t o l u e n e - d g s o l u t i o n r e s u l t i n g w h e n P P h 3 w a s a d d e d t o a - x x i -s o l u t i o n c o n t a i n i n g 50% R u C l c ( P P h Q ) . a n d A B C D c o m p l e x 2 2 0 1 5 . 2 8 . H-N. - .nur . . s p e c t r a a t .80 MHz o f a s o l u t i o n c o n t a i n i n g t h e A B C D s p e c i e s i n D M A / t o l u e n e - d g u s i n g s o l v e n t s u p r e s s i o n 2 2 2 31 1 5 . 2 9 P { H } ^ N . . 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 [ H ^ R u C l C P t o l ^ . ) w a s r e a c t e d w i t h > 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„ 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 „ C C , H r ) ( P P h J „ a f t e r b e i n g s h a k e n w i t h H „ . . . 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 ° 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 ° 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 ^ '•• P h ,. '. : •. 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 • 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 ( £ - 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 • 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 ^ - » » 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 ) . „ 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 ? • [lrH(uSBu ) ( C 0 ) ( P P h J J ? GG S ^ - P P h „ ^ (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 - — ' 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 ( • 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 + • 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 • 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 « 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 ° ( 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 ° - 6 0 ° 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 ° - 6 0 ° 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 ° ^ 6 0 ° 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 ° - 5 0 O C ( l i t . 2 8 47°-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 „ ( 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 „ ( 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 ) • ( 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 „ P o R u ^ r e q . u i . r e s . : C Y :6.Q H : 6 . 1 1 , 44 4° 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 . , , . - ... • , . , . , - 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 ) • DMA s o l v a t e , R u C l ^ T t o l ^ ) 2 ( D M A ) • (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 ) • ( 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 „ ( 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 ° 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 ) • ( 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 ) ^ » ( 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 ) • (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 ° C ) : P . = 6 0 . 0 p p m , P D = 52.4 p p m , J . „ = 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 ) »(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 ° 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 ® ( 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 ° 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 ° 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 ° 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 ^ • 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 « . 2 D M A 7 . R u C l 3 ( P P h 3 ) 2 ( D M A ) » , ( 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 ® ( 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 ° 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 ) • ( 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 ® ( 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 ® ( 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 ° 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 ° 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„ a t 2 0 2 0 c m " 1 ; 6 3 ° 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 ° 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 ° 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 „ C ^ . , . £ - 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 « 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 ° 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 ° 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 ' - £ - 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 - £ - 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 „ 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 • 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 . „ C ^ , . . £ - 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 ) ,«,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 ° - 6 0 ° 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 ™ 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 „44 , 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—L» 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 ° 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 „ . C 6 H 5 „ £ ^ C 6 H ^ F „ p - C ^ O C H ^ 3 7 » 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 - £ - 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 ° - 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 . Y i e l d : 0 . 7 2 5 g ( 8 5 $ ) ; C 6 1 H 5 0 ° 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 » 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°-60°C ) 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•orange 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$.;.. \^ B r„ at 2060, 2020 cm"1; r v u - n .30°C °C 6D 6: -10.20 (dt., 40.0 Hz, 34--4 Hz); ^ P{ H)-'n.m.r. (-60°C): 48.8 ppm, t ; 37 . 9 , t ; ^Jp p = 14 Hz.;. 3 1 P { p h e n y l protons}-n.m.r. spectra (-60°G) showed a d d i t i o n a l s p l i t t i n g . d u e to Jp ^, but the AA'KK'XX' pa t t e r n was not analyzed. The s p e c t r a l data are given i n Appendix A. The triphenylpho sphine.. d e r i v a t i v e , H 2Ru(PPh 3) ^  3 _ I t 5, was prepared by a s i m i l a r method but on.a s m a l l e r . s c a l e using i n s t e a d R u C l 0 ( P P h 0 ) 0 <• 3 3 (0.52g, 0.54' mmol) and PPh. (0.60g, 2.3 mmol). Y i e l d : 0.43g (70$). 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„ 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°C): 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„, 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 — 1 — •106 -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°C 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„ at ambient c o n d i t i o n s to C^D, or toluene-d„ 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 <to> H RuPo and fr e e phosphine; 6„. n : -7.1 (br, l i t . ' 4 C 6 D 6 -7.05); 3 1P{ 1H} (C 6D 6, 30°C): 58.0 ( s ) : 3 1P{ 1H} (toluene-dg, 30° to -65 C): 56,6 ppm ( s , t o t a l l y u naffected by s e l e c t i v e phenyl proton decoupling). 2.1..4.23 : Attempted, preparation of- d i 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 ) - ruthenium(II)., H^RuCPPh^) j. F o l l o w i n g the procedure of Levison and R o b i n s o n 3 8 , RuCl^^H^O (0.53g, 2v0 mmol) i n hot ethanol (20 mL).was added r a p i d l y to a v i g o u r s l y s t i r r e d s o l u t i o n - o f PPh^ (l..57g.,. 6.0 mmol) i n b o i l i n g ethanol (120.mL).. Subsequent r a p i d portionwi.se a d d i t i o n of WaBH 4 (0.38g, 10,0' mmol) i n hot ethanol .(20. mL) caused the mixture t o f i r s t become purple and then yellow before d e p o s i t i n g a brown s o l i d . This was f i l t e r e d . , washed with e t h a n o l , water, ethanol, and petroleum ether (30°-60°C.) (4O: mL, each), and vacuum-dried. Y i e l d : 1.50g (82$). The complex was i d e n t i f i e d . spectrosco.pically as being H^Ru^O) (PPh^) v^r at 1960-cm'1 . ( l i t ; . . 2 7 ' 3 8 1960 cm" 1); 3 1P{ 1H} ( C ^ , 30°C): 57.7 pp 2 d; 4.6,0 ppm, t ; J p p = 17 Hz. ( l i t . 2 3 61 .8 ppm.,. d; 47.5 ppm, t ; 2 31 Jpp = 17.5.Hz)', The present. P^n.m.r. assignments were confirmed by generating: H^Ru'tGO)C'PPh^.)^ i n s i t u by the r e a c t i o n of H^Ru^Ph^)^ with CO i n C . -27-2.1 ,4.24. Chlorohydrido (nor.bornadiene ) b i s (triphenylphosphine) -ruthe n i u m ( l l ) 2 7 ' , . HRuCl (nbd) (PPh 3) 2.. Norbornadiene (T mL) was added.to a suspension of HRuCl(PPh 3) 3.toluene (L.Og, 1 mmol) i n benzene (25 mL) at 25°C. A f t e r 18 h,. the brown s o l u t i o n was f i l t e r e d and added to petroleum ether (30 -60 C:, 150 mL).. S t i r r i n g .for 6-8 h gave a brown s o l i d , which was: f i l t e r e d , , washed with petroleum ether (30 -60 C), and vacuum-•dried... Y i e l d : 350mg (46$); C ^ H ^ C l P ^ u r e q u i r e s C: 68.4.7, I,. CI: 4.70$; .found C: 68.32, H: [ Ch a r a c t e r i z a t i o n , i s given i n Chapter 7. H: 5.21, , 5.36, CI: 4.61$; v J B r u 2020 cm"1. Ru-H 2..,1 ..,4.. 25 Dichloro(nor.bornadiene)bis(tri - p T r.tolylpho,sphine) ruthenium ( I I ) , R u C l 2 ( n b d ) ( P t o l 3 ) 2 . Norbornadiene (2 mL) was added to a suspension.of R u C l 2 ( P t o l 3 ) ^ (2g, 1.85 mmol) i n benzene (30 mL). A f t e r 24 h, the volume of the r e s u l t i n g y e l l o w s o l u t i o n was .reduced under vacuum to -10 mL, and petroleum ether (.30 , 6 0 C;. 50 mL) was added. The mixture was f i l t e r e d a f t e r s t i r r i n g 6 h, and the. s o l i d , washed w i t h petroleum ether (30°-60°) and vacuum-dried. Yield:. 1 .02g (63$); C , nH c nCl nP„Ru r e q u i r e s 0 49 50 2 2 ^ C: 67.4-3., H:- 5.77., CI: 8,12$.; found C:. 67,28, H: 5.98, CI: 8.00$; 6 3 0 D C : 3.81 (bs., 4H), 3,46 (bs., 2H).; 3 1 P { 1H} ; (CgDg, 30°C): 20.64 ppm, s. 6 6 2.1.4-26 C h l o r o d i carbonyl (norborneno.yl). b i s (triphenylpho sphine) -ruthenium (IT.).,. RuCl(G0.,C 7R g) (C0) 2(PPh 3)- 2. HRuCl(hbd)'-(.PPh3) 2 (0,30g., 0,40 mmol) was s t i r r e d i n benzene (10 mL) under.CO f o r 18 h, The yellow s o l u t i o n was f i l t e r e d to remove rsmall-amounts of, decomposition products contained- i n the s t a r t i n g -28-material, and the volume of the f i l t r a t e was reduced to -5 mL. The yellow product was precipitated with hexanes (20 mL), fi l t e r e d , washed with petroleum ether (30°-?60°C; 2 x 5 mL)., and vacuum-dried. Yield: 0.29g,(87$); C ^ H ^ O ^ l P ^ u requires C: 65.91, H: 4 . 6 9 , CI: 4 .12$.; found C: 65.88,. H: 4 . 6 O , CI: 4.04$. The complex i s further described in Chapter 7. 31 1 2.1.4,27 Other complexes; generation of -n.m.r. shift table. A series of phosphine complexes was prepared during the course of this work for use as standards in product analyses for in situ P{ H}-n.m.r. experiments,. While most of these compounds are known, 3 1 1 13 1 their P{' H'}vn,m,r. (and sometimes' C{ H^n.m.r.) chemical shifts are not, and so the.data, are presented in Table II-1. Using a modified .literature.procedure 5 1 ' 5 2 the complex RuCl 2(C0)' 2(PPh 3) 2 was prepared by stirring RuCl^PPh^) (l,0g, L O 4 mmol) in CH2C12 ("30 mL) under CO for.24 h. The white solid was precipitated with methanol (250 mL)., recrystallized. from hot CH2Cl2-methanol, fil t e r e d and vacuum-dried. Yield:. 0.75g (96$); C ^ H ^ O ^ l ^ R u requires C: 60.65, H: 4.02., CI: 9.42$; found C: 60,61, H: 3.97, CI: 9.42$'; v™ rat 2060,. 1995 (vs) cm"1 ( l i t , 5 2 2064, 2001 cm"1); 13C{1H}-n.m.r, (CDCl^, 25°C): 134.3 ppm (t, | j p c + J p 1 ( , | = 10.8 Hz; o-C); 131..8 ppm (t, | j p ( - , + J p ^ l = 4-9.6 Hz; carbon bound to P); 130.6 ppm (s,..-£-C).; 128,2 ppm (t, | j p c + J p, cl = 9.8 Hz, m-C). The geometry i s defined as . cis.-.,cis-,.trans-RuCl2(C0) 2(PPh^) 2 in accord 5 3 with previous findings . 5 1 5 2 Based on a literature procedure ' ., the complex HRuCl(C0) 2(PPh 3) 2 was prepared by stirring HRuCltPPh^) .,toluene - 2 9 -T A B L E 31 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 c o m p l e x e s ; p r e s e n t e d i n o r d e r o f i n c r e a s i n g u p f i e l d s h i f t C o m p o u n d 3 1 P { 1 H } - N . m . r . s h i f t , ppm ; H 2 R u ( C 0 ) 2 ( P P h 3 ) 2 b 5 7 . 7 R u ( C 0 ) - j ( P P h 3 ) 2 C 56.6 R u ( C 0 ) 2 ( P P h 3 ) 3 5 0 . 5 H R u ( 0 2 C C 6 H 5 ) ( C O ) 2 ( P P h 3 ) 2 ( C g H ^ C O O H ) 46.3 H R u ( 0 2 C C 6 H 5 ) ( C O ) ( P P h 3 ) 2 46.1 H R u C l ( C 0 ) 2 ( P P h 3 ) 2 C 3 9 . 9 R u C l ( 0 2 C C H 3 ) ( C 0 ) ( P P h 3 ) 2 3 6 . 0 R u ( 0 2 ) ( C 0 ) 2 ( P P h 3 ) 2 3 5 . 1 R u ( 0 2 C C H 3 ) 2 ( C 0 ) 2 ( P P h 3 ) 2 3 1 . 5 R u ( 0 2 C C 6 H 5 ) 2 ( C 0 ) 2 ( P P h 3 ) 2 3 1 . 5 R u C l 2 ( C 0 ) 2 ( P P h 3 ) 2 C 1 7 . 0 R u B r C l ( C 0 ) 2 ( P P h 3 ) 2 1 5 . 0 R u B r 2 ( C 0 ) 2 ( P P h 3 ) 2 1 3 . 3 R u I 2 ( C 0 ) 2 ( P P h 3 ) 2 8 : 7 I n C g D g a t 2 5 ° C ; r e p o r t e d s h i f t s a r e d o w n f i e l d f r o m 8 5 $ H 3 P 0 ^ « 31 1 T h e P { H } - n . m . r . r e s o n a n c e o f t h e d i d e u t e r i d e a n a l o g u e , D 2 R u ( C 0 ) 2 ( P P h 3 ) 2 < w a s a p o o r l y r e s o l v e d 1 : 2 : 3 : 2 : 1 q u i n t e t ; 2 J p D - 3 . 5 H z . 1 3 1 S h o w n b y C{ H } - n . m . r . t o c o n t a i n t r a n s p h o s p h i n e s . - 3 0 -( 1 . 0 g , 0 . 9 8 m m o l ) i n C H 2 C 1 2 ( 5 0 mL) u n d e r CO f o r 24- h . T h e w h i t e s o l i d w a s p r e c i p i t a t e d " w i t h m e t h a n o l ( 2 5 0 mL) . , r e c r y s t a l l i z e d f r o m h o t C H 2 C l 2 - m e t h a n o l , f i l t e r e d , a n d v a c u u m - d r i e d . Y i e l d : 0 . 6 7 g ( 9 5 $ ) ; C o o H o . 0 o C l P _ R u r e q u i r e s C : 6 3 . 5 6 , H : 4 . 3 5 , C I : 4 - 9 4 $ ; f o u n d C : 6 3 . 4 6 , 3o 3i 2 2 H : 4 . 7 0 , C I : 4 . 7 7 $ ; V ^ r a t 2 0 3 0 , 1 9 8 2 c m " 1 ( v s ) ( l i t . . 5 f u j o l 2 ° 4 2 , 1 9 9 5 c m " 1 ) ; 6 ^ ° :. - 3 . 8 6 ( R u - H , t , 2 0 ' H z ) ( l i t . ^ ' " ; - 4 . 5 3 , t , 19 H z ) ; 1 3 1 ^ ^ 3 C{ H} ( C D C 1 , 2 5 C ) : 1 3 4 . 1 ppm ( t , | j p G + J p | ( , | = 4 6 . 6 H z , c a r b o n b o u n d t o P ) ; 1 3 4 * 1 ppm ( t , | j p c + J P , C | = 1 3 . 3 H z , o - C ) ; 1 3 0 . 0 ppm ( s , J J - C ) ; 1 2 8 . 1 ppm (t.,. | j p ^ + J P L ( - , | = 9 . 5 H z , m - C ) . C o n s i s t e n t w i t h i n i t i a l a s s i g n m e n t s 5 1 ' , t h e . g e o m e t r y i s d e f i n e d a s c i s - , c i s - , t r a n s -R u H C l ( C 0 ) 2 ( P P h 3 ) 2 T h e c o m p l e x R u ( ' 0 2 C C H 3 ) ' 2 ( C 0 ) 2 ( P P h 3 ) 2 w a s p r e p a r e d b y s t i r r i n g R u C 0 2 C C H ) 2 ( P P h 3 ) 2 (0 . . .6g , ; 0 , 8 1 . m m o l ) i n T H F ( 1 0 mL) u n d e r CO f o r 3 6 h . T h e w h i t e 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 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 : 0 . 5 5 g ( 8 5 $ ) . ; C ^ H ^ O ^ R u r e q u i r e s C : 6 3 . 0 8 , H : 4 . 5 4 $ ; f o u n d C : 6 3 . 5 1 , H : 4 . 7 3 $ ; v ^ 1 * . a t 2040.,. 1 9 7 0 c m " 1 ( v s ) ; a t 1 6 1 0 ( v s , b ) , 1 3 7 0 ( s ) , 1 3 2 0 ( s ) c m " 1 ; 1 3 C { 1 H } ( C D C 1 3 > 2 5 ° C ) : 1 8 1 . 4 ppm ( s . , OgCCff ) ;. 1 3 4 . 7 ppm ( t , | j p c + J p I ( , | = 1 2 . 0 H z , o - C ) ; 1 3 0 . 0 ppm ( s , £ - C ) ; 1 2 8 , 1 ppm ( t , | j p c + J p , c l = 9 . 5 H z , m - C ) ; 2 2 . 0 ppm ( s , O g C C H ^ ) . A c o m p o u n d g i v i n g t h e same, i n f r a r e d s p e c t r u m w a s a l s o o b t a i n e d u s i n g 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 ( l i t . 3 7 v ^ n a t 2 0 4 4 , 1 9 7 3 c m " 1 ; v o c o a t 1613 . , 1 5 9 6 , . 1 3 1 5 c m " 1 ) . T h e s e a u t h o r s h a v e a s s i g n e d t h e g e o m e t r y . ,as t r a n s ? - , c i s - , c i s - R u ( 0 2 C C H , , ) 2 ( C 0 ) 2 ( P P h , J 2 > b u t t h e t r i p l e t 5 t f ? 5 5 r e s o n a n c e s o b s e r v e d , i n t h e p r e s e n t w o r k i n d i c a t e t h a t t h e P P h ^ g r o u p s a r e . m u t u a l l y t r a n s 5 6 , a n d t h e g e o m e t r y i s a s s i g n e d a s c i s - , , c i s ? .> t r ans - -Ru ( .0.A ,CCH o ) ^ ( C O ) ^ ( P P h O 0 . - 3 1 -T h e R u C l ( 0 o C C H o ) ( C 0 ) ( P P h J o , R u C l ( 0 - C C , H _ ) ( C O ) ( P P h J a n d 2 5 j> <. 2 o p i ti H R i ^ O g C C g H j J ( G O ) ( P P h ^ ) ^ c o m p l e x e s w e r e p r e p a r e d b y t h e l i t e r a t u r e m e t h o d s 3 7 . Y i e l d f o r R u C K O g C C R y ( C O ) ( P P h ^ ^ 0 . 1 5 g ( 6 2 $ ) ; G . n H _ _ 0 . C l P o R u r e q u i r e s C: 6 2 , 6 1 , H : 4 . 4 5 $ ; f o u n d C : 6 2 . 8 7 , H : 4 - 5 1 $ ; 39 3 3 3 2 V ™ 1 " a t 1 9 4 0 ( v s ) c m " 1 a n d a t 1 5 0 5 ( s ) , U 6 0 ( s ) c m " 1 ( l i t . 3 7 1941 , 1 5 0 7 , a n d 1 4 6 5 c m " 1 ) . Y i e l d f o r R u C l ( 0 _ C C , . H - ) ( C 0 ) ( P P h _ ) _ : 0 . 2 1 g ( 8 0 $ ) ; 2 o 5 3 2 C H 3 5 0 3 C l P 2 R u r e q u i r e s C : 6 5 . 2 3 , H : 4 . 3 5 $ ; f o u n d C : 64.88, H : 4 . 3 5 $ ; V£Q a t 1 9 4 0 ( v s ) c m " a n d v Q C Q a t 1 5 0 0 ( s ) a n d 1 4 0 0 ( s ) c m " ( l i t . 3 7 1 9 3 5 , 1 5 0 6 , a n d 1 4 4 6 c m " 1 ) . Y i e l d f o r H R u ( 0 n C C , H _ ) ( C O ) ( P P h J 0 . 2 1 g 2 o 5 3 2 ( 8 1 $ ) ; C ^ H ^ O ^ P g R u r e q u i r e s C : 6 8 , 1 2 , , H : 4 - 6 8 $ ; f o u n d C : 6 8 . 9 9 , H : 4 . 7 2 $ ; fc?5-. a t - 1 5 . 6 2 ( R u - E , t , 20 H z ; l i t , 3 7 a t - 1 6 . 3 5 , C D 0 C 1 0 , 6 6 t , 2 0 H z ) ; vjPr„ a t 2 0 0 0 . c m - 1 . , v ™ r a t 1 9 1 8 ( v s ) c m " 1 , a n d KU-n 01 ) V Q B J a t 1 5 1 5 ( s ) a n d 1 4 2 0 ( s ) c m " 1 ( l i t . 3 7 2 0 0 3 , 1 9 2 4 , 1 5 1 4 , a n d 1 4 2 5 cm 1 ) . T h e c o m p o u n d R u ( C 0 ) ^ ( P P h ^ ) ^ f f _ T ' s e s e r v e d a s a u s e f u l p r e c u r s o r f o r t h e g e n e r a t i o n o f s e v e r a l s p e c i e s . E x c e s s . -mobi le ' ' s o d i u m a m a l g a m w a s a d d e d t o a T H F s o l u t i o n . ( 9 0 mL) c o n t a i n i n g R u C l 2 ( C O ) 2 ( P P h 3 ) 2 ( 3 . 1 5 g , 4 . 2 m m o l ) a n d P P h ^ ( 2 , 4 g , 9 . 2 m m o l ) . T h e m i x t u r e w a s s t i r r e d u n d e r A r f o r 48 h . . T h e g r e e n s u s p e n s i o n w a s a l l o w e d t o s e t t l e ; t h e g r e e n i s h s u p e r n a t a n t 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 r e m o v e m o s t o f t h e s u s p e n d e d m e r c u r y a n d s a l t s a n d t h e f i l t r a t e w a s t a k e n t o d r y n e s s . T h e r e s i d u a l y e l l o w s o l i d w a s d i s s o l v e d i n b e n z e n e . , t h e s o l u t i o n b e i n g f i l t e r e d a g a i n t h r o u g h C e l i t e a n d t a k e n t o d r y n e s s , R e c r y s t a l l i z a t i o n f r o m T H F -h e x a n e s g a v e b r i g h t y e l l o w n e e d l e s , Y i e l d : 2 . 9 5 g ( 7 5 $ ) ; C ^ H . - O - P - R u r e q u i r e s C : 7 1 . 2 5 , H : 4 - 8 1 $ ; f o u n d C : 7 1 . 2 0 , H : 4 . 5 9 $ ; 5o 4 5 2 $ V ^ Q 1 " 1 8 9 8 ( v s ) . a n d 1 8 5 0 (w) c m " 1 ( l i t . 5 " ' , 1 9 0 5 c m " 1 ) . S a m p l e s t e n d e d t o c o n t a i n s m a l l a m o u n t s o f R u ( C 0 ) 0 ( P P h J „ a n d / o r H „ R u ( C 0 ) 0 ( P P h J _ Z> 3 2 2 2 5 2 - 3 2 -u n l e s s t h e r e s i d u a l m e t h a n o l . , u s e d i n t h e r e c r y s t a l l i z a t i o n o f t h e R u C l 2 ( C 0 ) 2 ( P P h 3 ) 2 s t a r t i n g m a t e r i a l , w a s r i g o r o u s l y r e m o v e d b y v a c u u m . T h e c o m p l e x e s R u ( X Y ) ( C O . ) ^ ( P P h ^ ) ^ ( X I = H 2 ? 7 ' r < ? ' 6 0 , O ^ " 7 , a n d C 0 3 8 . . f i » 5 9 - ( . » ) w e r e p r e p a r e d b y s t i r r i n g R u ( C O ) 2 ( P P h 3 ) 3 ( 0 . 6 0 g , O.64 mmol) . i n T H F ( 2 0 mL) u n d e r 1 a t m o f t h e a p p r o p r i a t e g a s a t 2 5 ° C f o r 6 h . . T h e 0 2 c o m p l e x , d e p o s i t e d . , w a s f i l t e r e d , w a s h e d w i t h 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 : . 0...32 g (7.0 .%)•;. C o o H o n 0 . P „ R u r e q u i r e s JO JU 4 2 C : 63.95, H : 4-24$; f o u n d C : 6 3 . 8 8 , . H : 4.29$; V ^ r a t 2 0 0 0 ( v s ) a n d 1 9 3 8 ( v s ) ' c m " 1 a n d *.at 8 5 2 (m) c m - 1 ( l i t . . 5 " 1 , 2 0 0 5 , 194-5 , a n d _ 1 R u 0 2 " 8 4 9 cm )-. T h e CO a n d H 2 a d d u c t s w e r e p r e c i p i t a t e d b y a d d i n g h e x a n e s t o t h e T H F s o l u t i o n s . Y i e l d f o r R u ( C 0 ) 3 ( P P h 3 ) 2 : 0 . 4 1 g ( 9 0 $ ) ; C „ n H „ ~ 0 _ P o R u r e q u i r e s C : . 66 , 0 1 . , H : 4 . 2 6 $ . ; f o u n d C : 6 5 - 9 0 , H : 4 . 3 7 $ ; 39 JU 3 2 v^v a t 1 8 9 0 ( v s ) c m - 1 ( l i t . . * 1 , . 1 8 9 5 c m " 1 ) . ; . 1 3 C { 1 H } - n . m . r . ( C D C l ^ 2 5 ° C ) : 2 5 ° C ) : 1 3 6 . 5 ppm ( t , | j p c + J p , - C ] = 47.9 H z , c a r b o n b o u n d t o P ) ; 1 3 3.6 ppm ( t , | j p c + J p , c | = 1 3 . 0 H z , o ^ C ) ; 1 2 9 . 8 ppm ( s , j a - C ) ; 1 2 8 , 1 ppm ( t , | J p c + J p , c | = 1 0 , 3 H z , m - C ) . Y i e l d f o r H 2 R u ( C 0 ) 2 ( P P h 3 ) 2 : 0 . 3 7 g ( 8 5 $ ) ; 6 , ? 5 n a t . - 6 . 3 0 ( R u - H , t , 2 3 H z ; l i t . . " , - 6 . 3 0 , t , 2 3 . 5 6 6 2 3 . 5 H z ) ; v ^ r a t 2 0 0 0 ( v s ) a n d 1 9 6 2 ( v s ) c m - 1 a n d \EBru a t 1 8 7 5 (mw) U U Hu -n a n d 1 8 2 0 (mw) c m " 1 ( l i t . * 8 , 2015, 1 9 7 0 , 1 8 7 0 , a n d 1 8 2 0 c m " 1 ) . T h e 31 P c h e m i c a l s h i f t s f o r t h e s e c o m p l e x e s w e r e a l s o o b t a i n e d s i m p l y b y s h a k i n g C ^ D ^ s u s p e n s i o n s o f R u ( C 0 ) 2 ( ' P P h 3 ) u n d e r t h e r e q u i r e d g a s . I n t h i s w a y , t h e s p e c t r u m o f D 2 R u ( C 0 ) 2 ( ' P P h 3 ) 2 - w a s o b t a i n e d . T h e 3 1 P c h e m i c a l s h i f t s f o r R u B r 2 ( C 0 ) 2 ( P P h 3 ) 2 a n d R u I 2 ( C 0 ) 2 ( P P h 3 ) 2 w e r e o b t a i n e d s i m i l a r l y b y a d d i n g s t o i c h i o m e t r i c a m o u n t s o f B r 2 a n d I 2 » r e s p e c t i v e l y , t o C ^ D ^ s o l u t i o n s o f R u ( ' G O ) 2 ( P P h 3 ) y T h e , s i g n a l f o r f r e e P P h 3 w a s o b s e r v e d - i n a l l i n s i t u e x p e r i m e n t s a t - 3.9 p p m . C a r b o n y l a t i o n o f R u B r 2 ( P P h 3 ) 3 i n T H F , b y a p r o c e d u r e i d e n t i c a l w i t h t h a t d e s c r i b e d -33-f o r R u ( 0 2 C C H 3 ) 2 ( C 0 ) 2 ( P P h 3 ) 2 . , g a v e t h e d i c a r b o n y l p r o d u c t R u B r 2 ( C 0 ) 2 ( P P h 3 ) 2 ( v ^ r a t 204-6 ( v s ) a n d 1978 ( v s ) c m - 1 ; l i t > ' , 2050, -1 31 1990 cm ) w h i c h e x h i b i t e d t h e same P r e s o n a n c e a t 13.3 ppm a s a b o v e , c o n f i r m i n g t h e a s s i g n m e n t o f t h i s s i g n a l . Some s a m p l e s o f R u B r ^ P P h ^ ) ^ , 31 h o w e v e r , g a v e c a r b o n y l a t e d p r o d u c t s w h i c h s h o w e d a n a d d i t i o n a l P s i n g l e t a t 15 .0 p p m . I n v i e w o f t h e d i f f i c u l t y i n p r e p a r i n g R u B r ^ P P h ^ ) ^ f r e e f r o m c h l o r i d e - c o n t a i n i n g s p e c i e s 6 8 , a n d s i n c e t h i s p e a k p o s i t i o n i s a t a p p r o x i m a t e l y t h e a v e r a g e p o s i t i o n o f s i g n a l s f o r R u C l 2 ( C 0 ) 2 ( P P h 3 ) 2 (17.0 ppm) a n d R u B r 2 ( C 0 ) . 2 ( P P h 3 ) 2 (13.3 p p m ) , t h i s r e s o n a n c e i s a s s i g n e d t e n t a t i v e l y t o R u B r C l ( C O ) 2 ( P P h 3 ) 2 » T h e a b s e n c e o f t h i s p e a k a t 15-0 ppm i n c a r b o n y l a t e d s a m p l e s o f R u B r 2 ( P P h 3 ) 3 s e r v e d a s a c r i t e r i o n o f p u r i t y f o r t h i s t r i s ( p h o s p h i n e ) s p e c i e s ( C h a p t e r 3 ) . T h e n e w c o m p l e x H R u ^ C C g H ^ ) ( C O ^ P P h . ^ - ( C g H ^ C O O H ) w a s p r e p a r e d b y a d d i n g s o l i d R u ( C 0 ) 2 ( P P h 3 ) (0 ,20g , 0.21 m m o l ) t o a T H F s o l u t i o n (5 mL) o f b e n z o i c a c i d (0 .34g , 2.8 m m o l ) . T h e m i x t u r e w a s s t i r r e d a t 25°C u n t i l t h e r u t h e n i u m c o m p l e x f u l l y d i s s o l v e d . t o g i v e a p a l e y e l l o w s o l u t i o n . A f t e r a d d i n g d i e t h y l e t h e r (20 m L ) , t h e v o l u m e w a s r e d u c e d t o 3 m L , A d d i t i o n o f p e t r o l e u m e t h e r ( 3 0 ° - 6 0 ° C ) (30 m L ) , f o l l o w e d a g a i n b y v o l u m e r e d u c t i o n u n d e r v a c u u m , p r o v i d e d s u f f i c i e n t c o o l i n g t o p r e c i p i t a t e a w h i t e s o l i 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 c o l d p e t r o l e u m e t h e r ( 3 0 ° -r60°C)(5 mL) a n d v a c u u m d r i e d . Y i e l d : 0.11g (65%). T h e e l e m e n t a l a n a l y s i s ( f o u n d C : 67.21,, H : 4.68$) d i d n o t d i f f e r e n t i a t e b e t w e e n t h e b e n z o i c a c i d . a d d u c t , H R u ( 0 o C C / H c ) ( C O ) ~ ( P P h _ . ) • ti o o ti 3 ti ( C g H ^ C O O H ) ( C ^ H ^ O g P g R u r e q u i r e s C : 67.45,- H : 4-57$) a n d t h e b e n z o i c a c i d - f r e e s p e c i e s , H R u ( 0 2 C C g H ^ ) (CO) 2 ( P P h 3 ) 2 ( C ^ H ^ O ^ R u r e q u i r e s C : 67.24-, H : .4.51%), b u t t h e f o r m e r f o r m u l a t i o n i s m o r e c o n s i s t e n t - 3 4 -w i t h t h e i n f r a r e d s p e c t r a l d a t a ( F i g u r e 2.2): v r n a t 204.0 ( s ) a n d *1 K B r 1 1 9 6 0 ( v s ) c m " , V Q £ Q a t 154-0 ( s ) a n d 1 3 7 5 ( s ) c m " ' ( c o o r d i n a t e d m o n o -d e n t a t e b e n z o a t e ) a n d 1 7 0 8 ( s ) a n d 1245 ( s , b r ) c m " ( h y d r o g e n b o n d e d b e n z o i c a c i d 3 7 ) . 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 i n t h e 1 H - n . m . r . ( C ^ D ^ , 2 5 ° C , - 3 . 5 2 6 , t , 2 0 H z ) i s c l o s e t o t h a t f o u n d f o r c i s , c i s , t r a n s H R u C l ( C 0 ) 2 ( P P h 3 ) 2 ( - 3 . 8 6 6 , t , 2 0 H z ) , a n d t h e d a t a c o l l e c t i v e l y s u g g e s t t h e s t r u c t u r e I . CO/*,, P P h 3 . . . » * H " ^ C - P h c o - ^ o ^ o - - H P P h 3 Ph I t h e 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 o f b e n z o i c a c i d ( s e c t i o n 6 . 2 . 2 ) . - 3 5 -T h i s d i c a r b o n y l s p e c i e s c o u l d n o t b e g e n e r a t e d p u r e b y a d d i t i o n o f s o l i d b e n z o i c a c i d t o b e n z e n e o r T H F s o l u t i o n s of . R u ( C O ) g C P P h ^ ) 3 ; i n s u c h c a s e s , , t h e P{ H } - n . m . . r . . s p e c t r a s h o w e d m o s t l y t h e p r e s e n c e o f e q u i m o l a r a m o u n t s o f R u ( C 0 ) 3 ( P P h 3 ) 2 ( 5 6 . . 6 ppm) a n d H R u t O g C C g H ^ ) ( C O ) ( P P h ^ ) 2 ( 4 6 . I ppm). , w h i c h i s a t t r i b u t e d t o t h e r e a c t i o n o f t h e p r o d u c t H R u ( 0 _ C C , H C ) ( C 0 ) o ( E P h - . ) _ w i t h r e s i d u a l R u ( C O ) J P P h J . : H R u ( 0 2 C C 6 H 5 ) ( C O ) 2 ( P P h 3 ) 2 + R u ( C 0 ) 2 ( P P h 3 ) 3 H E u f Q ^ S : ^ ) ^ + P P h 3 ( 2 . 1 ) E x a m i n a t i o n o f t h e d a t a i n T a b l e I I - 1 s h o w s a n i n t e r e s t i n g 31 r e l a t i o n s h i p f o r t h e P c h e m i c a l s h i f t s o f t h e c i s , c i s , t r a n s R u ( X Y ) ( C O ) 2 ( P P h 3 ) 2 s p e c i e s ( X Y = H , C I , 0 2 C R , B r ) . T h e c h e m i c a l s h i f t s m o v e s i g n i f i c a n t l y d o w n f i e l d w i t h i n c r e a s i n g h y d r i d e s u b s t i t u t i o n , a n d t h e e f f e c t i s a d d i t i v e . F o r e x a m p l e , t h e c h e m i c a l s h i f t o f H R u C l ( C O ) 2 ( P P h 3 ) 2 ( 3 9 , 9 ppm) i s a l m o s t t h e a v e r a g e v a l u e ( 3 7 . 4 ppm) f o r t h e s h i f t s - o f H 2 R u ( C 0 ) 2 ( P P h 3 ) 2 ( 5 7 . . 7 ppm) a n d R u C l 2 ( C 0 ) 2 ( P P h 3 ) 2 31 ( 1 7 . 0 p p m ) . W h i l e t h e n a t u r e o f t h e P c h e m i c a l s h i f t s h a s b e e n e x p l a i n e d t h e o r e t i c a l l y 6 3 ' 6 4 , t h e i n t e r p l a y o f f a c t o r s ( e . g . t h e d e g r e e o f d o r b i t a l o c c u p a t i o n a n d g e o m e t r i c a l s y m m e t r y d e v i a t i o n s ) h a s n o t y e t p e r m i t t e d a q u a n t i t a t i v e i n t e r p r e t a t i o n o f e x p e r i m e n t a l l y o b s e r v e d c h e m i c a l s h i f t s 6 5 ' 6 6 . . I n t h e c i s . , c i s , t r a n s c o m p l e x e s , t h e g e o m e t r i c a l - - • s y m m e t r y - . d e v i a t i o n s a r e - ~ e x p e c t e d ' . ' t o be- s m a l l - ' b e c a u s e o f t h e b u l k o f t h e P P h 3 l i g a n d s . ' S i m i l a r l y - , : o t h e r d i c a r b o n y l c o m p l e x e s w i t h t r a n s p h o s p h i n e s may b e e x p e c t e d t o s h o w l i t t l e g e o m e t r i c a l v a r i a t i o n i n t h e " R u ( C O ) 2 ( P P h 3 ) 2 " m o i e t y . T h e 3 1 P c h e m i c a l s h i f t s o f t h e t r a n s p h o s p h i n e s m o v e s . d o w n f i e l d a s X Y = H 2 > CO > ( H ) ( 0 2 C R ) > ( H ) ( ' C l ) > - 3 6 -0 2 > ( 0 2 C R ) 2 > ( C l ) 2 > ( B r ) ( C I ) > ( B r ) 2 > ( l ) 2 > w h i c h i s i n t h e o r d e r o f i n c r e a s i n g s i z e o f X Y 5 7 . B y n o n - b o n d i n g r e p u l s i o n s , s u c h a n i n c r e a s e w o u l d f o r c e a l e n g t h e n i n g o f t h e r u t h e n i u m - p h o s p h o r u s b o n d s , w i t h a 31 d e c r e a s e i n t h e o v e r l a p , a n d t h e P s h i f t s a r e p r o b a b l y r e f l e c t i n g t h i s . 31 S u c h a n e m p i r i c a l c o r r e l a t i o n o f P c h e m i c a l s h i f t s w i t h 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 r u t h e n i u m - p h o s p h o r u s b o n d l e n g t h s c a n a l s o b e made f o r t h e p h o s p h i n e s i n R u C l ^ P P h ^ , H R u C l ( P P h 3 ) , H R u ( 0 2 C C H 3 ) ( P P h ^ ) y [ H R u ( n 6 - C 6 H 5 P P h 2 ) ( P P h 3 ) 2 ] [ B F j , a n d [ H 2 R u C l ( P t o l 3 ) 2 l 2 , - w h i c h " . . g i v e s s u p p o r t f o r t h i s i d e a ( F i g u r e 2 . 3 ; T a b l e I I - 2 ) . xi -p M fi 0) T3 a o CP 2 . 4 0 2 . 3 5 2 . 3 0 A 2 . 2 5 H 2 . 2 0 10 -r 30 50 70 9 0 D o w n f i e l d c h e m i c a l s h i f t , ppm 1 1 0 F i g u r e 2 . 3 P l o t o f 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 v s . 31 P c h e m i c a l s h i f t s i n t h e s l o w e x c h a n g e r e g i o n s f o r t h e c o m p l e x e s l i s t e d i n T a b l e I I - 2 . - 3 7 -T A B L E 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 i . r . s h i f t , ppm B o n d l e n g t h , R C o m p l e x 9 4 . 0 5 8 2 . . 2 0 6 6 9 H R u C l ( P P h 3 ) 3 7 8 . 1 6 8 2 . 2 3 9 7 0 H R u ( 0 o C C H j ( P P h J o 7 6 . 9 C 2 . 2 3 8 , C [ H 2 R u C l ( P t o l 3 ) 2 ] 2 7 5 , 7 6 . 8 2 , 2 3 0 7 1 R u C l 2 ( P P h 3 ) 3 6 0 . 4 ° 2 . 2 8 , 2 . 2 6 8 , c [ H 2 R u C l ( P t o l 3 ) 2 J 2 48.9 7 2 2 , 3 1 1 , 2 . 3 3 2 7 2 H R u ( n 6 - C 6 H 5 P P h 2 ) ( P P h 3 ) 2 + U . 3 6 8 2 , 3 5 4 , 2 . 3 6 3 7 0 H R u ( 0 2 C C H 3 ) ( P P h 3 ' ) 3 3 8 . 6 6 8 ' 2.361.,. 2 . 3 2 9 6 9 H R u C l ( P P h 3 ) 3 2 7 . 9 C 2 . 3 9 8 ' ° [ H 2 R u C l ( P t o l 3 ) 2 ] 2 2 4 . 1 6 8 2 . 3 7 4 , 2 . 4 1 2 7 1 R u C l 2 ( P P h 3 ) 3 a D a t a t a k e n f r o m , r e f e r e n c e s a s i n d i c a t e d b y s u p e r s c r i p t s ; s e e a l s o F i g u r e 4»6 a n d T a b l e V I - 4 o f t h e p r e s e n t w o r k . b D o w n f i e l d s h i f t s a r e p o s i t i v e ; , r e f e r e n c e d t o 85$ H Q P 0 . 3 4 c S e e C h a p t e r 4 o f t h i s w o r k . -38-2 . 2 I n s t r u m e n t a t i o n . I n f r a r e d s p e c t r a w e r e r e c o r d e d a s K B r d i s c s o n a P e r k i n E l m e r 4 5 7 o r 598 g r a t i n g s p e c t r o p h o t o m e t e r c a l i b r a t e d w i t h t h e 1601 cm p e a k o f p o l y s t y r e n e . V i s i b l e s p e c t r a w e r e r e c o r d e d o n P e r k i n E l m e r 2 0 2 o r 5 5 2 A s p e c t r o -p h o t o m e t e r s , f i t t e d w i t h 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 s , u s i n g a n a e r o b i c s p e c t r a l c e l l s w i t h q u a r t z c e l l s o f 1 . 0 cm o r 1 . 0 mm p a t h l e n g t h ( F i g u r e 2 . . 4 ) , A b s o r b a n c e d a t a f o r k i n e t i c e x p e r i m e n t s w e r e o b t a i n e d f r o m t h e d i g i t a l d i s p l a y o n t h e M o d e l 5 5 2 A i n s t r u m e n t a t t h e w a v e l e n g t h o f i n t e r e s t . T i m e s w e r e r e c o r d e d f r o m a L a b - C h r o n 14-00 t i m e r . 1 1 H - N u c l e a r m a g n e t i c r e s o n a n c e ( . H - n . m . . r . ) s p e c t r a w e r e r e c o r d e d o n B r u c k e r WP80 ( 8 0 MHz f o r H)..,, V a r i a n X L 100 ( 1 0 0 MHz f o r ' H ) , o r B r u c k e r WH4OO (4OO MHz f o r H ) s p e c t r o m e t e r s . , o r p e r a t i n g i n t h e F o u r i e r t r a n s f o r m mode w i t h t e t r a m e t h y l s i l a n e ( T M S ) a t 0 . 0 6 a s s t a n d a r d . 31 1 31 P{ H } - a n d P { p h e n y l p r o t o n } r n . m . r , s p e c t r a w e r e r e c o r d e d o n t h e V a r i a n X L 1 0 0 (4O..505 MHz f o r 3 1 P ) o r B r u c k e r WP80 (32.4 MHz f o r 3 1 P ) s p e c t r o m e t e r s e q u i p p e d w i t h . v a r i a b l e t e m p e r a t u r e a t t a c h m e n t s a n d o p e r a t i n g i n t h e F o u r i e r t r a n s f o r m , m o d e . T h e s t a n d a r d f o r P { ' H } -n . m . r . s p e c t r a w a s t h e s i g n a l f o r t r i m e t h y l p h o s p h i t e a t + I 4 I . O ppm 7 3 a t 30°C, t h i s b e i n g r e l a t i v e t o 8 5 $ H P 0 , D o w n f i e l d s h i f t s a r e t a k e n i 4 1 3 1 a s p o s i t i v e , a n d a r e r e p o r t e d r e l a t i v e t o 8 5 $ IL ,P0 : . C{ H } - N . m . r . . 3 . 4 1 3 s p e c t r a w e r e o b t a i n e d o n t h e B r u c k e r WH4OO ( 1 0 0 MHz f o r C ) o r V a r i a n OFT 2 0 ( 2 0 MHz f o r 1 3 C ) s p e c t r o m e t e r s . E v o l v e d h y d r o g e n f r o m s o l u t i o n r e a c t i o n s ( s e e C h a p t e r 4) w a s i d e n t i f i e d u s i n g a C a r l e A n a l y t i c a l G a s C h r o m a t o g r a p h M o d e l 311 - 4 0 -( t h e r m a l c o n d u c t i v i t y d e t e c t o r ) w i t h a I 4 f o o t h a n d - p a c k e d P o r a p a k Q c o l u m n ( W a t e r s A s s o c i a t e s , M e s h 8 0 - 1 0 0 ) , U s i n g a h e l i u m c a r r i e r g a s a t 20 p . . s . i . a t 3 0 ° C , t h e w a s w e l l r e s o l v e d f r o m t h e o t h e r g a s e s a n d h a d a r e t e n t i o n t i m e o f 1 9 5 ± 5 s e c . E l e c t r o n s p i n r e s o n a n c e ( e . s . r . ) s p e c t r a w e r e o b t a i n e d o n a V a r i a n E 3 s p e c t r o m e t e r , u s i n g s o l i d s a m p l e s i n e v a c u a t e d q u a r t z e . s . r . t u b e s a t r o o m t e m p e r a t u r e o r - 1 9 6 ° C . T h e l o w t e m p e r a t u r e s w e r e m a i n t a i n e d b y . u s i n g a D e w a r j a c k e t . T h e i n s t r u m e n t w a s c a l i b r a t e d w i t h d i p h e n y l p i c r y l h y d r a z y l ( D P P H ) . w h i c h h a s a s i g n a l a t g = 2 . 0 0 2 . T h e g v a l u e s w e r e c a l c u l a t e d u s i n g t h e r e l a t i o n s h i p ? i f , ' : hv K - 2 7 w h e r e h = P l a n k ' s c o n s t a n t = 6 . 6 2 6 x 10 e r g - s e c . 3 = B o h r m a g n e t o n = 9 . 2 7 3 2 x 1 0 ~ 2 1 e r g / G . V = m e a s u r e d m i c r o w a v e f r e q u e n c y ( t y p i c a l l y 9 . 1 0 0 G H z ) a n d H Q = m a g n e t i c f i e l d ( 2 0 0 0 - 4 0 0 0 G ) . 2 . 3 P r o c e d u r e f o r m o n i t o r i n g r e a c t i o n o f c o m p l e x e s w i t h H ^ u s i n g  P - n . m . r . R e a c t i o n s w e r e m o n i t o r e d b y " " P - n . m , r . o n t h e X L 1 0 0 s p e c t r o m e t e r . T y p i c a l l y , . 30mg o f c o m p l e x w e r e d i s s o l v e d o r s u s p e n d e d i n t h e a p p r o p r i a t e s o l v e n t . I n t h e h y d r o g e n a t i o n s t u d i e s , s e v e r a l p r e c u r s o r s w e r e i n i t i a l l y i n s o l u b l e o r o n l y s l i g h t l y s o l u b l e , b u t t h e n d i s s o l v e d 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 p r e s e n c e o f s o l i d m a t e r i a l i n . t h e n . m . r . . t u b e d i d n o t seem t o . h a v e m u c h e f f e c t o n t h e l i n e s h a p e s o f t h e s p e c t r a , , n o r d i d t h e s o l u t i o n v i s c o s i t y , a l t h o u g h p r o b l e m s - 4 1 -w e r e o c c a s i o n a l l y e n c o u n t e r e d w i t h t h e l o c k c h a n n e l a n d s i g n a l - t o - n o i s e l e v e l i n t h e s e c a s e s . W h e r e i n d i c a t e d . , D M A / ' t o l - u e r i e - d 0 . ; o r - D M A / C . D ' / s o l u t i o n s ! w e r e a p p r o x i m a t e l y 1:1 ( v / v ) i n e a c h s o l v e n t a n d t h e t o t a l v o l u m e w a s a p p r o x i m a t e l y 0 , 5 t o ' 1 . 0 mL w i t h [ R u ] ^ - 1 0 t o 1 0 M . I n t h e h y d r o g e n a t i o n s t u d i e s , t h e . o b j e c t s o f m o s t i n t e n s e s t u d y w e r e t h e p r i m a r y p r o d u c t s , s i n c e t h e s e w e r e b e l i e v e d t o b e i n t e r m e d i a t e s t h a t r e a c t e d f u r t h e r w i t h . t o g i v e . , f o r e x a m p l e , a f i n a l p r o d u c t s u c h a s [ H g R u C l E g ] ^ . . . T h e t i m e s g i v e n , t h e n , i n t h e i n d i v i d u a l d i s c u s s i o n s r e f e r t o t h e t i m e t h e s o l u t i o n w a s l e f t , u s u a l l y a t r o o m t e m p e r a t u r e , , u n d e r h y d r o g e n , . I t i s a s s u m e d t h a t d u r i n g t h e a c c u m u l a t i o n o f s p e c t r a . , , t h e l o w p r o b e t e m p e r a t u r e s e f f e c t i v e l y q u e n c h e d a n y / r e a c t i o n s . . T h e s a m p l e s w e r e r e c h a r g e d w i t h h y d r o g e n d u r i n g t h e t i m e i n t e r v a l s a t a m b i e n t t e m p e r a t u r e s . U n d e r t h e e x p e r i m e n t a l c o n d i t i o n s t h e n , t h e c h e m i s t r y o b s e r v e d r e p r e s e n t s a f r e e z i n g o u t o f t h e r o o m t e m p e r a t u r e e q u i l i b r i a a n d p r o c e s s e s . N o r m a l i n s t r u m e n t s e t t i n g s a r e l i s t e d b e l o w : S p e c t r a l w i d t h . - 1 0 0 0 0 H z P u l s e w i d t h - 30 u s e e N u m b e r o f t r a n s i e n t s - 2 t o 30 t h o u s a n d O f f s e t - 4 4 4 4 4 H z S p e c t r u m a m p l i t u d e - 2 5 0 D e c o u p l e r o f f s e t - 4 5 3 0 7 H z D e c o u p l e r p o w e r r- h e t e r o h i g h 5 0 - 8 0 D e c o u p l e r b a n d w i d t h - 2 0 0 0 H z 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 w e r e d o n e b y i r r a d i a t i n g t h e a r o m a t i c r e s o n a n c e s o f P P h ^ . o r P t o l ^ a t 7 5 0 H z d o w n f i e l d f r o m T M S . O p t i m u m r e s u l t s w e r e o b t a i n e d b y o f f s e t t i n g t h e d e c o u p l i n g c h a n n e l t o 4 5 5 5 7 H z - 4 2 -( C ^ D ^ , C D C l ^ ) o r 4-6078 H z ( t o l u e n e - d g m e t h y l s i g n a l ) , , a n d s e t t i n g t h e h e t e r o h i g h p o w e r l e v e l a n d d e c o u p l i n g b a n d w i d t h t o z e r o . . I n a l l r u t h e n i u m s y s t e m s w h e r e J p ^ o f a h y d r i d e c o u l d b e m e a s u r e d i n d e p e n d e n t l y f r o m H - n . . m . r , . e x p e r i m e n t s , , t h e v a l u e s o b t a i n e d w e r e i d e n t i c a l . T h e l i m i t a t i o n , o f t h i s m e t h o d , h o w e v e r , , w a s s e e n i n t h e h a f n i u m - b o r o h y d r i d e c o m p l e x , H f 2 - y - H 3 - y - , ( B H ) 3 [ N ( S i t C H ^ C H ^ C C H ^ g ) 2 ] 2 ( s u p p l i e d b y P r o f e s s o r M , F r y z u k a n d H . : W i l l i a m s ' • o f - t H i . s d e p a r t m e n t ) , w h e r e t h e d i s t a n c e b e t w e e n t h e i r r a d i a t e d s i g n a l a n d t h e h y d r i d e 31 r e s o n a n c e w a s 7 5 3 H z . . I n t h i s c a s e , t h e J p ^ o b t a i n e d f r o m t h e P s p e c t r u m w a s s l i g h t l y l e s s t h a n t h a t f r o m t h e H - n . m . r . s p e c t r u m ( 8 . 0 v s . 8 . 6 H z ) . 2.4 G a s u p t a k e . a p p a r a t u s , a n d m e a s u r e m e n t . 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 p p a r a t u s u s e d f o r d e t e r m i n i n g g a s s t o i c h i o m e t r i e s a n d k i n e t i c s t u d i e s i s s h o w n s c h e m a t i c a l l y i n F i g u r e 2 . 5 . . T h e p y r e x t w o - n e c k r e a c t i o n f l a s k ( A ) , e q u i p p e d w i t h . a d r o p p i n g s i d e - a r m b u c k e t , , w a s a t t a c h e d t o a f l e x i b l e g l a s s s p i r a l t u b e , w h i c h c o n n e c t e d f l a s k A t o a c a p i l l a r y m a n o m e t e r ( D ) a t t a p . C . T h e r e a c t i o n f l a s k w a s c l i p p e d . t o a p i s t o n - r o d a n d w h e e l , w h i c h w a s d r i v e n b y a W e l c h v a r i a b l e s p e e d e l e c t r i c m o t o r so t h a t t h e f l a s k c o u l d b e s h a k e n w h i l s t h e l d i n t h e t h e r m o s t a t t e d o i l . b a t h ( B ) . . T h e o i l b a t h c o n s i s t e d o f a f o u r l i t e r g l a s s b e a k e r f i l l e d w i t h s i l i c o n e o i l (Dow C o r n i n g 5 5 0 ) , a n d w a s h e l d i n a p o l y s t y r e n e - f o a m l i n e d w o o d e n b o x f o r i n s u l a t i o n . T h e c a p i l l a r y m a n o m e t e r c o n t a i n e d . . n . - b u t y l p h t h a l a t e , o f n e g l i g i b l e v a p o r p r e s s u r e , a n d w a s c o n n e c t e d t o t h e g a s m e a s u r i n g b u r e t t e w h i c h - u -h a d a p r e c i s i o n b o r e d t u b e ( N ) o f k n o w n d i a m e t e r a n d a m e r c u r y r e s e r v o i r ( E ) . T h e c a p i l l a r y m a n o m e t e r a n d g a s m e a s u r i n g b u r e t t e w e r e t h e r m o -s t a t t e d a t 2 5 ° C i n a p e r s p e x w a t e r b a t h . B y m e a n s o f a n E d w a r d s h i g h v a c u u m n e e d l e v a l v e ( M ) , t h e b u r e t t e w a s c o n n e c t e d t o t h e g a s - h a n d l i n g p a r t o f t h e a p p a r a t u s . T h e l a t t e r c o n s i s t e d o f a m e r c u r y m a n o m e t e r ( F ) , t h e g a s i n l e t ( Q ) , a n d c o n n e c t i o n s t o a W e l c h D u o - S e a l r o t a r y v a c u u m p u m p . ( G ) . T h e t h e r m o s t a t t i n g o f t h e t w o b a t h s w a s c o n t r o l l e d b y J u m o t h e r m o - r e g u l a t o r s a n d M e r c - t o - M e r c r e l a y c o n t r o l c i r c u i t s , w i t h 4O w a t t e l o n g a t e d l i g h t b u l b s u s e d f o r h e a t i n g . T h i s , w i t h m e c h a n i c a l s t i r r i n g , m e a n t t h a t t h e t e m p e r a t u r e c o u l d b e m a i n t a i n e d w i t h i n ± 0 . 0 5 ° C . T h e g a s - u p t a k e w a s m e a s u r e d w i t h a v e r t i c a l l y m o u n t e d c a t h e t o m e t e r . I n e a c h e x p e r i m e n t , 1 0 mL o f DMA w a s p i p e t t e d i n t o t h e 2 5 mL r e a c t i o n f l a s k . T h e w e i g h e d c o m p l e x w a s s u s p e n d e d o n t h e h o o k o f t h e s i d e a r m o f t h e r e a c t i o n f l a s k . W i t h t h e f l a s k c o n n e c t e d t o t h e s p i r a l a r m , i t w a s a t t a c h e d t o t h e gas-r h a n d l i n g p a r t o f t h e a p p a r a t u s a t j o i n t 0 . T h e s u b s t r a t e s o l u t i o n w a s d e g a s s e d b y a f r e e z e a n d t h a w s t a t i c v a c u u m t e c h n i q u e w h i c h w a s c a r r i e d o u t t h r e e t i m e s . T h e r e a c t i o n f l a s k w a s t h e n f i l l e d w i t h g a s t o a p r e s s u r e s l i g h t l y l e s s t h a n t h a t r e q u i r e d , a n d t a p s C a n d P w e r e c l o s e d . T h e f l a s k a n d s p i r a l a r m c o u l d t h e n b e r e m o v e d a n d c o n n e c t e d t o t h e c a p i l l a r y m a n o m e t e r a t H . T h e f l a s k w a s p l a c e d i n t h e o i l - b a t h . , , a n d . a t t a c h e d t o t h e m o t o r d r i v e n s h a k e r ( i ) w h i c h : w a s t h e n s t a r t e d . T h e w h o l e s y s t e m u p t o t a p C w a s e v a c u a t e d w i t h t a p s H , K , L , J , a n d M o p e n . A f t e r 10 m i n u t e s s h a k i n g t o a t t a i n t h e r m a l e q u i l i b r a t i o n o f t h e r e a c t i o n f l a s k a n d t o s a t u r a t e t h e s o l u t i o n w i t h g a s , , t h e s h a k i n g w a s s t o p p e d . , a n d h y d r o g e n w a s a d m i t t e d t o t h e r e s t o f t h e a p p a r a t u s a t p r e s s u r e s l i g h t l y l e s s t h a n r e q u i r e d . T a p G w a s o p e n e d a n d t h e p r e s s u r e o f h y d r o g e n i n c r e a s e d t o t h a t d e s i r e d . -45-, T h e - - n e e d l e - v a l v e , - . , a n d - t a p s K / a n d i w e r e c l o s e d : ; "'."and t h e i n i t i a l r e a d i n g o f t h e m e r c u r y l e v e l i n H t a k e n . A n e x p e r i m e n t a l r u n w a s s t a r t e d b y d r o p p i n g t h e b u c k e t c o n t a i n i n g t h e c o m p l e x , a n d s t a r t i n g t h e s h a k e r a n d t i m e r . T h e g a s - u p t a k e w a s i n d i c a t e d b y t h e d i f f e r e n c e i n t h e o i l l e v e l s o f t h e m a n o m e t e r ( D ) . T h e m a n o m e t e r w a s b a l a n c e d b y a l l o w i n g g a s t o t h e b u r e t t e t h r o u g h t h e n e e d l e v a l v e a n d t h e r e b y m a i n t a i n i n g a c o n s t a n t p r e s s u r e i n t h e r e a c t i o n f l a s k . T h e c o r r e s p o n d i n g r i s e i n t h e m e r c u r y l e v e l i n N w a s m e a s u r e d a t a p p r o p r i a t e i n t e r v a l s o f t i m e . S i n c e t h e d i a m e t e r o f t h e m a n o m e t e r ( N ) w a s k n o w n , , t h e v o l u m e o f g a s c o n s u m e d c o u l d b e c a l c u l a t e d a n d e x p r e s s e d a s m m o l e s o f u p t a k e p e r mg ( m m o l e ) o f c o m p l e x . T h e s o l u b i l i t y o f h y d r o g e n i n DMA a t s p e c i f i c t e m p e r a t u r e s a n d p r e s s u r e s w a s d e t e r m i n e d u s i n g t h e g a s - u p t a k e a p p a r a t u s d i s c u s s e d p r e v i o u s l y . T h e DMA w a s d e g a s s e d , b u t w a s l e f t u n d e r v a c u u m w h e n t a p s C a n d P w e r e c l o s e d a n d t h e f l a s k w i t h t h e s p i r a l a r m t r a n s f e r r e d t o t h e c a p i l l a r y m a n o m e t e r . T h e s y s t e m w a s t h e n e v a c u a t e d t o t a p C a n d f i l l e d w i t h h y d r o g e n t o t h e a p p r o x i m a t e p r e s s u r e r e q u i r e d . T a p G w a s o p e n e d , , a n d t h e p r e s s u r e i m m e d i a t e l y a d j u s t e d t o t h a t r e q u i r e d . W i t h t a p s K a n d L , a n d t h e n e e d l e v a l v e c l o s e d , t h e t i m e r a n d s h a k e r c o u l d b e s t a r t e d , , a n d t h e i m m e d i a t e u p t a k e o f g a s c o u l d b e m e a s u r e d . T h i s same p r o c e d u r e w a s u s e d t o . d e t e r m i n e g a s s t o i c h i o m e t r i c s f o r c o m p l e x e s w h i c h a p p e a r e d t o r e a c t w i t h g a s i n t h e s o l i d s t a t e i n t h e p r e s e n c e o f s o l v e n t v a p o r . . . B y m e a s u r i n g t h e d i f f e r e n c e o f g a s u p t a k e b e t w e e n t h e s o l u t i o n w i t h c o m p l e x a n d n e a t s o l v e n t , a c c u r a t e m e a s u r e m e n t s c o u l d . b e a c h i e v e d . T h e t e r m " g a s e n t r y m e t h o d " r e f e r s t o e x p e r i m e n t s d o n e i n t h i s w a y . -46-C H A P T E R 3. T H E -NATURE;' O F DICHLORQ;- , AND. . .DTBROMOTRIS ( 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 N S O L U T I O N . • 3.1 I n t r o d u c t i o n -S i n c e a n i n i t i a l - r e p o r t , i n . 1966 b y W i l k i n s o n a n d S t e p h e n s o n , R u C l g C P P h ^ ) ^ 3 1 , .'and;,, t o , a m u c h - l e s s e r e x t e n t , . , t h e b r o m o a n a l o g u e h a v e .commanded^ c o n s i d e r a b l e . . a t t e n t i o n - b o t h , a s . a c a t a l y s t f o r a w i d e v a r i e t y of- - o r g a n i c , t r a n s f o r m a t i o n s 1 . ' 7 5 - 8 2 , , a n d a s t h e p r e c u r s o r f o r t h e h y d r i d e , , , H R u G l ' . ( P P h 3 ) y. T h e - c r y s t a l s t r u c t u r e of. R u C l ^ P P h ^ 7 1 r e v e a l e d t h a t . , , a t l e a s t - i n t h e s o l i d s t a t e . , t h e c o m p l e x e x i s t s a s a d i s t o r t e d - s q u a r e p y r a m i d , , . . R u t h e n i u m ( I T ) c o m p l e x e s a r e l o w s p i n d a n d p r e f e r t o . b o s i x - c o o r d i n a t e , p r e s u m a b l y , b e c a u s e o f - t h e h i g h c r y s t a l - f i e l d ' s t a b i l i z a t i o n e n e r g y of- t h i s c o n f i g u r a t i o n . O t h e r s y s t e m s ^ w i t h s m a l l e r . / p h o s p h i n e s a c h i e v e t h i s b y a d d i n g a d d i t i o n a l l i g a n d s t o - f o r m c o m p l e x e s . o f t h e t y p e R u C l (PR. ) 8 3 , o r b y f o r m i n g <• 3 4 n e u t r a l o r e a t i o n i c d o u b l y . - o r t r i p l y - b r i d g e d d i m e r s 8 1 * d e p e n d i n g o n t h e - - p o l a r i t y o f • t h e s o l v e n t , u s e d i n t h e . s y n t h e s i s . I n t h e t r i p h e n y l -p h o s p h i n e c a s e > t h e b u l k o f t h e l i g a n d 6 7 a p p a r e n t l y p r e v e n t s t h e r u t h e n i u m c e n t e r . f r o m a t t a i n i n g t h i s p r e f e r r e d g e o m e t r y . A l t h o u g h i n t h e c r y s t a l , ; o n e - l i g a n d p h e n y l . r i n g o c c u p i e s t h e - s i x t h c o o r d i n a t i o n s i t e i n R u G l g C P P h ^ ) ^ , - , t h e r e i s n o s p e c t r a l e v i d e n c e t o s u g g e s t t h a t t h e r e i s a n y d i r e c t i n t e r a c t i o n -be tween- t h i s r i n g a n d t h e m e t a l a t o m . - 4 7 -T h e p r o x i m i t y h a s b e e n a t t r i b u t e d t o a p a c k i n g e f f e c t 6 8 . A n e x a m -i n a t i o n o f t h e l i t e r a t u r e b y C a u l t o n a n d H o f f m a n n 6 - 8 " ' 8 5 r e v e a l e d that-" d ^ c o m p l e x e s , w h e n t h e y c a n b e i n d u c e d t o b e f i v e - c o o r d i n a t e , p r e f e r a s q u a r e p y r a m i d a l g e o m e t r y , a n d t h i s w a s e x p l a i n e d o n e l e c t r o n i c g r o u n d s 8 6 . I n s o l u t i o n , h o w e v e r , e x t e n s i v e d i s s o c i a t i o n o f p h o s p h i n e o c c u r r e d . I n i t i a l 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 a c e t o n e o r b e n z e n e u n d e r n i t r o g e n i n d i c a t e d v a l u e s t h a t w e r e a b o u t h a l f t h a t e x p e c t e d 3 1 , s u g g e s t i n g r e a c t i o n s o f t h e t y p e : R : i C i ? . ( ? ? r : 3 ) 3 + s o l v e n t » . . R u C l 2 ( P P h 3 ) 2 ( s o l v e n t ) + P P h 3 (3.D L a t e r s p e c t r o s c o p i c s t u d i e s o n t h i s s y s t e m 6 8 ' ' 1 1 - i n . b e n z e n e ' w e r e i n t e r -. preted 'in- terms :• o f • t h i s t y p e o f " e q u i l i b r i u m ; - . H o w e : v ' e r , u s i n g P{ H } -n . m . r . e v i d e n c e C a u l t o n a n d H o f f m a n n 6 8 ' 8 5 a n d S t e p h e n s o n a n d c o -w o r k e r s 8 ' i n d e p e n d e n t l y a r g u e d a g a i n s t t h i s i n t e r p r e t a t i o n . I n t o l u e n e o r c h l o r i n a t e d " s o l v e n t s ( ' C D J D 1 , , , . o r C D C l J ' R u C l 0 P „ ('P = P P h „ , P t o l J - • ' <• 2. 3 it 3 3 3 s h o w s a t e m p e r a t u r e d e p e n d e n t s p e c t r u m , i n d i c a t i v e o f a f l u x i o n a l m o l e c u l e . T h e expected.A X 2 p a t t e r n b e c o m e s r e s o l v e d o n l y a t - 9 7 ° C ( 6 A = 7 5 . 7 p p m , 6 x = 2 4 . 1 p p m , 2 J p p = 31 H z ) 3 3 ' 6 8 . I n a d d i t i o n t o t h e s e s i g n a l s , a t l o w t e m p e r a t u r e s , a n A B p a t t e r n b e c o m e s e v i d e n t ( a t - 9 7 ° C , 6^ = 5 8 . 8 , 6 p = 5 3 . 0 p p m , ^Jpp = 4-1-5 H z ) . T h e s e r e s o n a n c e s w e r e a s s i g n e d t o a d i m e r ( i ) . a n d i n d i c a t e d - - t h a t t h e b u l k e q u i l i b r i u m 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 h o u l d b e r e g a r d e d a s : K 2 2 R u C l 2 P 3 [ R u C l 2 P 2 ] 2 + 2 P ( 3 . 2 ) C I . p -: R u ; P - C I . •ci-p I R u : -p •ci ( I ) A l t h o u g h t h e t r a n s i e n t m o n o m e r i c s p e c i e s , R u C l ^ P g , w a s n e v e r d i r e c t l y o b s e r v e d , i t w a s i n v o k e d t o e x p l a i n t h e i n t e r m o l e c u l a r p h o s p h i n e e x c h a n g e p r o c e s s i n R u C l ^ ' O P P h y ^ 7 Q, 3 5 I n . 1 9 7 7 , J a m e s a n d c o - w o r k e r s 8 i s o l a t e d 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 A B p a t t e r n a n d s h o w e d b y m o l e c u l a r w e i g h t m e a s u r -m e n t s t h a t i t w a s d i m e r i e i n t o l u e n e ( c a l c u l a t e d , 1 3 9 0 ; f o u n d , 1 2 0 0 ) . I n c o n t r a s t , t h e b i s ( p h o s p h i n e ) s p e c i e s a p p e a r e d t o e x i s t i n DMA a s a m o n o m e r . A v i s i b l e s p e c t r o p h o t o m e t r y s t u d y a n d c o n d u c t i v i t y m e a s u r -m e n t s i n t h i s s o l v e n t w e r e i n t e r p r e t e d i n . . t e r m s o f t h e t w o e q u i l i b r i a ^ 1 R u C l 2 P 3 R u C l 2 P 2 + P R u C l 2 P 2 „ 3 - R u C l P 2 + . + . C I " ( 3 . 3 ) ( 3 . 4 ) N o s u c h i o n i z a t i o n h a s b e e n o b s e r v e d i n a c e t o n e , b u t i t d o e s o c c u r i n n i t r o m e t h a n e , w h e r e s i g n i f i c a n t s o l v e n t b l - n d ! n : g ; l s ' b e l i e v e d 8 7 t o b e i n v o l v e d : + S R u C l 2 P 3 S = C H 3 N 0 2 ; P = P P h 3 S-C l -P I . R u . S-( 3 . 5 ) -49-8 8 C o n s i s t e n t w i t h t h i s i o n i c f o r m u l a t i o n , A s h w o r t h a n d S i n g l e t o n h a v e r e c e n t l y i s o l a t e d [ R u C l ( C H C N ) 3 ( P P h 3 ) 2 ] [ P F g ] v i a [ R u C l ( C 8 H 1 2 ) ( C H C N ) 3 ] [ P F 6 ] . C o n d u c t i v i t y m e a s u r e m e n t s a t 25°C o n s o l u t i o n s o f R u C l ^ P P h ^ ) . ^ i n DMA g a v e i n i t i a l e q u i v a l e n t c o n d u c t a n c e . v a l u e s o f c a . 10 ohm 2 -1 cm m o l , i n d i c a t i n g t h e p r e s e n c e o f i o n i c s p e c i e s . H o w e v e r , c o n s i s t e n t c o n d u c t i v i t y r e s u l t s c o u l d n o t b e o b t a i n e d b e c a u s e o f t h e e x t r e m e o x y g e n s e n s i t i v i t y o f t h e . d i l u t e s o l u t i o n s . T h e a u t h o r s r e c o g n i z e d t h i s p r o b l e m , b u t f o u n d t h a t s o l u t i o n s c o n t a i n e d i n a n a e r o b i c c e l l s u n d e r v a c u u m r e m a i n e d u n c h a n g e d , w h i l e a d d i t i o n o f c h l o r i d e i o n ( a s L i C l ) c a u s e d s p e c t r a l c h a n g e s w h i c h w e r e c o n s i s t e n t w i t h t h e f o r m a t i o n o f " R u C l g P g " » 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 i n t o l u e n e . Q u a n t i t a t i v e m e a s u r e m e n t s i n d i c a t e d t h a t t h e e x t e n t o f t h i s i o n i z a t i o n w a s s m a l l (<25% a t 10 M r u t h e n i u m ) . L a t e r ^ ' P { H } - n . m . r . s t u d i e s o n ' [ • R u C l g C ' P P h ^ ) 2 ' ] 2 ? £ k i n DMA . w e r e 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 m o n o m e r i c f o r m u l a t i o n s . I n D M A , 31 1 t h e s y s t e m e x h i b i t e d o n l y a s h a r p s i n g l e t i n t h e P { H } - n . m . r . s p e c t r u m a t a m b i e n t c o n d i t i o n s a t 64.9 ppm. . T h i s w a s a s s i g n e d t o R u C l 2 ( D M A ) 2 ( P P h 3 ) 2 , b y a n a l o g y w i t h o t h e r s i x - c o o r d i n a t e c o m p l e x e s ' On a d d i t i o n o f c h l o r i d e i o n , t h i s s i g n a l s h i f t e d t o 48.il p p m . . - A l t h o u g h t h e e x a c t n a t u r e o f t h e p r o d u c t w a s n o t d e t e r m i n e d , t h e r e s u l t s o f some o t h e r p r e l i m i n a r y w o r k i n t h i s l a b o r a t o r y i n d i c a t e d t h a t t h e r e a c t i o n w i t h c h l o r i d e i o n may h a v e b e e n a s s o c i a t i v e i n n a t u r e T h e i n i t i a l i n t e n t o f t h i s s t u d y w a s t o u n d e r s t a n d t h e s o l u t i o n c h e m i s t r y o f R u G l ^ C P P h ^ ) ^ i n D M A . i n ' t h e p r e s e n c e , o f c h l o r i d e i o n , a s s u c h u n d e r s t a n d i n g o f f e r e d t o c l e a r u p some a n o m a l i e s i n a r e p o r t e d k i n e t i c s t u d y ( s e e C h a p t e r 5 ) • D u r i n g t h e c o u r s e o f t h i s w o r k , h o w e v e r , i t w a s a l s o n e c e s s a r y t o r e - e v a l u a t e t h e n a t u r e 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 n D M A . I n a n a t t e m p t t o d e t e r m i n e w h e t h e r a p a r t i c u l a r m e t h o d o f d a t a m a n i p u l a t i o n c o u l d d i f f e r e n t i a t e b e t w e e n a m o n o m e r i c a n d d i m e r i c d i s s o c i a t i o n p r o d u c t f o r u s e i n . t h e DMA s y s t e m , a s w e l l a s t o o b t a i n t h e a p p r o p r i a t e ' e q u i l i b r i u m c o n s t a n t s , t h e l i g a n d d i s s o c i a t i o n s f r o m R u X ^ P P h ^ ) ^ ( X = C I , B r ) i n t o l u e n e h a v e b e e n r e - e x a m i n e d s p e c t r o p h o t o m e t r i c a l l y . F o r t h e s a k e o f c l a r i t y i n t h e e n s u i n g d i s c u s s i o n s , t h e f o l l o w i n g e q u i l i b r i u m c o n s t a n t s a r e d e f i n e d ( P = P P h 3 ) : K1 : R u X 2 P 3 „ R u X 2 P 2 + P ( 3 ' 3 ) K 2 : 2RuX 2 P 3 „ [ R u X 2 P 2 ] 2 + 2P (3.6) K 3 : R u C 1 2 P 2 ^ R u C l P 2 + + C l " (3.4) : [ R u C l 2 P 2 ] 2 + C l " = ^ R u 2 C l 5 P ^ " (3.7) K 5 : 2 R u C l 2 P 2 + C l " = ^ R u 2 C l 5 P ~ (3.8) K 6 : 2 R u C l 2 P 3 + C l " =^i= R u g C l ^ " + 2P (3.9) 3 . 2 E x p e r i m e n t a l . 3.2.1. S a m p l e p r e p a r a t i o n a n d m a n i p u l a t i o n . R u C l 2 ( P P h 3 ) 3 w a s c h o s e n a s t h e r u t h e n i u m s o u r c e f o r t h e s e e q u i l i b r i u m s t u d i e s b e c a u s e i t c o u l d b e o b t a i n e d v e r y p u r e . A l t h o u g h u s e o f t h e d i m e r [ R u C l 2 ( P P h 3 ) 2 ] 2 w o u l d h a v e h a d g r e a t e x p e r i m e n t a l a d v a n t a g e s , i t c o u l d n o t b e p r e p a r e d s u f f i c i e n t l y p u r e b y a n a l y s i s f o r ( -51-i t s u s e t o b e j u s t i f i e d . A s P h ^ C I * 2 1 1 ^ 0 w a s c h o s e n a s t h e c h l o r i d e s o u r c e i n p r e f e r e n c e t o L i C l b e c a u s e t h e c o n c e n t r a t i o n s o f t h e f o r m e r c o u l d m o r e a c c u r a t e l y b e d e t e r m i n e d . F o r t h e s e e q u i l i b r i u m s t u d i e s , i t w a s m o s t a c c u r a t e a n d c o n v e n i e n t t o p r e p a r e t w o s t o c k s o l u t i o n s o f e q u a l r u t h e n i u m c o n c e n t r a t i o n s . T h i s m i n i m i z e d e r r o r s d u e t o w e i g h i n g t o <A% a n d t h e e r r o r s i n s o l u t i o n c o m p o s i t i o n w e r e n o t c u m u l a t i v e . I n a l l c a s e s , t h e s o l u t i o n s w e r e v e r y a i r s e n s i t i v e , b u t s o l u t i o n t r a n s f e r s w e r e c o n v e n i e n t l y made b y g r a d u a t e d M o h r p i p e t t e s ( 1 0 . 0 mL a n d 1 . 0 m L ) , a f t e r p u r g i n g t h e p i p e t t e a n d p r o - p i p e t t e f o u r t i m e s w i t h a r g o n . T h e l a y e r o f a r g o n a b o v e t h e s o l u t i o n s p r e v e n t e d a i r . o x i d a t i o n o f t h e s o l u t i o n s d u r i n g t h e s h o r t t r a n s f e r t i m e s . T h r e e v a r i a t i o n s o f t h e s a m p l e p r e p a r a t i o n s w e r e u s e d , a n d t h e s e a r e b e s t d e s c r i b e d b y w a y o f e x a m p l e s : ( a ) I n t h e p h o s p h i n e e q u i l i b r i u m . s t u d i e s , t h e R u C l g t P P h ^ ) ^ s y s t e m i n t o l u e n e s e r v e s a s a g o o d e x a m p l e . T o l u e n e w a s ' c h o s e n i n p r e f e r e n c e t o b e n z e n e b e c a u s e t h e l o w e r v a p o r p r e s s u r e made h a n d l i n g s i m p l e r . I n t h i s c a s e , 1 2 8 mg o f R u C l ^ P P h ^ ) y w e r e d i s s o l v e d i n 1 0 0 . 0 mL o f t o l u e n e , t o g i v e a s t o c k s o l u t i o n . A . ( d e s i g n a t e d [Ru] ) o f 1 . 3 3 x 1 0 " M . A s e c o n d s t o c k s o l u t i o n B w a s p r e p a r e d b y t r a n s f e r r i n g 4-0.0 mL o f s o l u t i o n A o n t o 1 8 6 . 5 mg P P h 3 ( [ R u ] . ' T A = [Ru]^ , : p ; [ P P h ^ g = 1 . 7 8 x l O " 2 M ) . T h e p a r t i c u l a r [ P P h ^ ] ^ was, c h o s e n a f t e r p r e l i m i n a r y e x p e r i m e n t s i n d i c a t e d t h a t t h i s w a s a t t h e l o w e r c o n c e n t r a t i o n , l e v e l r e q u i r e d t o p r o d u c e a l i m i t i n g s p e c t r u m o f R u C l ^ P P h ^ ) T h e c o n c e n t r a t i o n o f a d d e d p h o s p h i n e w a s v a r i e d b y m i x i n g v o l u m e s o f A a n d B s u c h t h a t t h e t o t a l v o l u m e w a s 5 . 0 m L . T y p i c a l l y , t h e 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 i n t h e s p e c t r o -p h o t o m e t e r ' s 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 u n t i l t h e r e w a s n o c h a n g e -52-i n t h e a b s o r b a n c e a t a p a r t i c u l a r w a v e l e n g t h ( n o t t h e w a v e l e n g t h o f i n t e r e s t ) o v e r a p e r i o d o f f i v e m i n u t e s . T h r e e t e s t s w e r e d o n e t o c h e c k t h e v a l i d i t y o f t h e e x p e r i m e n t a l p r o c e d u r e . F i r s t , t h e c o n c e n -t r a t i o n o f a d d e d P P h ^ w a s d e c r e a s e d b y 10$ (4.5 mL o f s o l u t i o n B + 0.5 mL o f s o l u t i o n A ) a n d t h e r e s u l t i n g s p e c t r u m w a s s h o w n t o b e t h e same a s t h a t o f s o l u t i o n B , i n d i c a t i n g t h a t s o l u t i o n B ( t h e l i m i t i n g h i g h p h o s p h i n e s o l u t i o n ) c o n t a i n e d f u l l y f o r m e d R u X ^ P P h ^ ) , ^ S e c o n d , t h e a p p e a r a n c e a n d m a i n t e n a n c e o f i s o s b e s t i c p o i n t s i n d i c a t e d t h a t [ R u ] ^ = [ R U ] ^ ; t h a t i s , n o d i l u t i o n e f f e c t s a n d n o a p p r e c i a b l e o x i d a t i o n o f r u t h e n i u m w a s o c c u r r i n g . L o s s o f . i s o s b e s t i c s w o u l d r e f l e c t o n l y g r o s s o x i d a t i o n , b e c a u s e w i t h a d d e d p h o s p h i n e , t r a c e s o f o x y g e n w o u l d " 9 2 b e r e m o v e d a s p h o s p h i n e o x i d e , e f f e c t i v e l y d e c r e a s i n g t h e a d d e d p h o s p h i n e c o n c e n t r a t i o n w i t h o u t a f f e c t i n g 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 . T o m i n i m i z e t h i s p o s s i b i l i t y , t h e s o l u t i o n s w e r e r u n i n r a n d o m o r d e r , a n d some w e r e r e p e a t e d a t d i f f e r e n t t i m e s . I f i r r e p r o -d u c i b l e w i t h t i m e , t h e d a t a w e r e d i s c a r d e d , f r e s h s o l u t i o n s w e r e p r e p a r e d , a n d t h e e x p e r i m e n t r e p e a t e d . T h i s w a s a p a r t i c u l a r p r o b l e m i n t h e s t u d i e s i n D M A . I n s e v e r a l t r i a l s , t h e c o m p l e x R u C l ^ P P h ^ ) ^ a p p e a r e d t o b e u n s t a b l e i n t h i s s o l v e n t , t h e s p e c t r a s h o w i n g s l o w g e n e r a l d e c r e a s e s i n a b s o r b a n c e w i t h t i m e . T h e d e c a y w a s s l o w e r a t h i g h e r p h o s p h i n e c o n c e n t r a t i o n s , a n d w a s c o n s i d e r e d t o b e d u e t o some t r a c e i m p u r i t y i n t h e s o l v e n t ( s e e s e c t i o n 5 . 3 : 2 . ) . P r e l i m i n a r y e q u i l -i b r i u m • s t u d i e s • f o r . e q u a t i o n - 3 . 2 - u s i n g s u c h u n s t a b l e . " s o l u t i o n s g a v e v a l u e s w h i c h w e r « - s l i g h ' t i y . ' - l a r g e r (10 2?< 2 . 2 . % 3..9, 2.6, 1.2 'A) t h a n t h e v a l u e f i n a l l y o b t a i n e d ( 1 0 2 K 2 D M = 1.5 ± 0.5 k ) . ( b ) F o r t h e s t u d y i n v o l v i n g r e a c t i o n ( e q u a t i o n 3 .9) , s a m p l e m a n i p u l a t i o n a n d c h e c k s w e r e e s s e n t i a l l y t h e same a s d e s c r i b e d a b o v e , - 5 3 -b u t s l i g h t m o d i f i c a t i o n s w e r e made i n s o l u t i o n p r e p a r a t i o n s . A s t o c k s o l u t i o n A o f r u t h e n i u m a n d c h l o r i d e w e r e p r e p a r e d s u c h t h a t [Ru]™ . = 1 , A 1 . 0 6 x 1 0 " 3 M a n d a d d e d [ C l ~ ] . = 2 . 0 3 x 1 0 " 3 M . A l l o f t h e r u t h e n i u m w a s s h o w n t o b e p r e s e n t a s R u 0 1 ( P P h ) " . T r i p h e n y l p h o s p h i n e ( 2 . 6 2 1 g) <- 5 3 4 w a s d i s s o l v e d i n 5 0 . 0 mL o f s o l u t i o n A t o g i v e s o l u t i o n B i n w h i c h [ R u ] T a = [ R u ] T b , [ C 1 " ] A = [ C 1 " ] B , a n d [ P P h 3 ] B = 0 . 2 0 0 M , t h i s p h o s p h i n e c o n c e n t r a t i o n b e i n g c o n v e n i e n t f o r t h e a n a l y s i s . H o w e v e r , s o l u t i o n B d i d n o t y i e l d t h e l i m i t i n g h i g h p h o s p h i n e s p e c t r u m . T h e v a l u e u s e d i n t h e c a l c u l a t i o n s was o b t a i n e d f r o m s e p a r a t e l y d e t e r m i n e d m e a s u r e m e n t s . T h e p r e s e n c e o f a c l e a n i s o s b e s t i c p o i n t a t 4 4 9 nm i n d i c a t e d t h a t t h e e f f e c t o f a d d i n g s u c h a l a r g e a m o u n t o f s o l i d p h o s p h i n e t o s o l u t i o n B w a s n e g l i g i b l e . ( c ) F o r t h e c o n t i n u o u s v a r i a t i o n m e t h o d o f J o b 9 3 ' 9 4 , a s t o c k s o l u t i o n A o f R u C l 2 ( P P h 3 ) 3 i n DMA w a s p r e p a r e d s o t h a t . [ R u ] T a = 1 . 2 4 x 1 0 " 3 M . D i l u t i o n w i t h DMA g a v e a s e r i e s o f s o l u t i o n s t h a t o b e y e d a l i n e a r B e e r ' s L a w p l o t ( r e g r e s s i o n c o n s t a n t , R = 0 . 9 9 7 4 ) . T h e same s t o c k s o l u t i o n A w a s t h e n d i l u t e d w i t h DMA s o l u t i o n s o f c h l o r i d e ( [ C l ~ ] _ = 1 . 2 5 x 1 0 M) o v e r t h e same r u t h e n i u m c o n c e n t r a t i o n r a n g e . I n t h i s w a y , t h e sum [ R u ] ^ , + [ C I ] ^ r e m a i n e d c o n s t a n t . B y u s i n g t h e same r u t h e n i u m s t o c k s o l u t i o n f o r b o t h d i l u t i o n p r o c e d u r e s , e r r o r s i n v a r i a t i o n o f s o l u t i o n c o m p o s i t i o n w e r e g r e a t l y r e d u c e d . ( N o t e : t o b e w h o l l y r i g o r o u s , t h e p r o c e d u r e s h o u l d b e d o n e a t t w o d i f f e r e n t w a v e -l e n g t h s . I n t h i s s t u d y t h o u g h , n o o t h e r s u f f i c i e n t l y d i f f e r e n t w a v e -l e n g t h l e n t i t s e l f t o t h e m e t h o d . ) -54-3 . 2 . 2 . C a l c u l a t i o n s . T h e r e w e r e t h r e e b a s i c t y p e s o f e q u i l i b r i u m c a l c u l a t i o n s : ( 1 ) d i r e c t m e a s u r e m e n t s , i n w h i c h l i m i t i n g s p e c t r a o f b o t h r e a c t a n t s a n d p r o d u c t s w e r e k n o w n ( K g ) ; ( 2 ) a p p r o x i m a t i o n m e t h o d s , i n w h i c h o n l y o n e l i m i t i n g s p e c t r u m w a s k n o w n ( a s i n p h o s p h i n e d i s s o c i a t i o n s t u d i e s ) ; a n d ( 3 ) J o b ' s m e t h o d . T h e c a l c u l a t i o n s a r e p r e s e n t e d i n t h i s o r d e r , w i t h a n i n c r e a s i n g d e g r e e o f c o m p l e x i t y . 3 . 2 . 2 . 1 . D e t e r m i n a t i o n o f K g . T h e e q u i l i b r i u m : 2 R u C l _ ( P P h J - + C l " - R u 0 C l c ( P P h J " + 2PPh_ ( 3 . 9 ) 2 3 3 2 5 3 4 3 I . I I i s r e p r e s e n t e d b y t h e e q u i l i b r i u m c o n s t a n t : DMA [ R u C l P - ] [ P ] 2 Kg A = 9 4 ( 3 . 1 0 ) [kuci 2 P 3 ] 2 [ci~] F o r t h e p u r p o s e o f t h e c a l c u l a t i o n s , t h e a m o u n t o f r u t h e n i u m c o n t a i n e d i n d i m e r s i s e x p r e s s e d i n t e r m s o f ' m o n o m e r c o n c e n t r a t i o n ' ( d e s i g n a t e d [ I I ] ) . T h i s r e p r e s e n t s t h e c o n c e n t r a t i o n o f r u t h e n i u m a t o m s w h i c h e x i s t a s t h e d i m e r i c ; b l s ( p h o s p h i n e ) ' s p e c i e ' s . . ' - W i t h - ' t h i s ' c o n v e n t i o n , t h e DMA e x p r e s s i o n f o r K g a n d t h e r e m a i n i n g e q u i l i b r i a , 3 5 5 ' c a n ^ e w r i t t e n w i t h [ l l ] a s t h e o n l y v a r i a b l e . U n d e r t h e c o n d i t i o n s o f t h e e x p e r i m e n t , a l l o f t h e t e r m s o f K g a r e e x p r e s s e d w i t h r e s p e c t t o [ l l ] a s f o l l o w s : [ R u 2 C l 5 P ^ ] [ C l " ] [ R u 2 C l 5 P ^ - ] ' f r e e L J a d d e d ^ T o t a l = t R u C 1 2 P 3 ] + ° r [ R u C l 2 P 3 ] = [ I ] = [ R U ] T [ C l ' l - 4 [11] [ P ] f r e e [?] a d d e d [ I I ] ( 3 . 1 1 ) ( 3 . 1 2 ) ( 3 . 1 3 ) (3 .U ) T h e s u b s c r i p t s " T " , " f " , a n d " a " d e s i g n a t e " t o t a l " , " f r e e " , a n d " a d d e d " , r e s p e c t i v e l y , s o t h a t , f o r e x a m p l e , [ p ] r e f e r s t o t h e c o n c e n t r a t i o n o f f r e e p h o s p h i n e . C o m b i n i n g : *[!!]([?]„ + [II])' ( [ R u L - [n])2([cil - 4 [ 11 ] R e a r r a n g i n g [ R u ] = [ i ] + [ l l ] y i e l d s : [II] [Ru L (1 + [l]/[n]} ( 3 . 1 5 ) ( 3 . 1 6 ) I f A ^ = l i m i t i n g a b s o r b a n c e a t h i g h a d d e d [ P P h ^ ] a n d l o w , : [ C 1 ] , a n d A q = l i m i t i n g a b s o r b a n c e a t [ ? ] '• - D' a n d . h Lg'r. [ C l ~ ] , a n d A = some i n t e r m e d i a t e a b s o r b a n c e , t h e n A - A [I] [ R u ] , ( 3 . 1 7 ) - 5 6 -[ I I ] A - A CO A - A oo 0 ;[.Ru]r ( 3 . 1 8 ) o r i n ] A - A A - A ( 3 . 1 9 ) a n d K g i s e s t i m a t e d d i r e c t l y f r o m ( 3 . 1 5 ) a n d ( 3 . 1 8 ) . T h e d a t a a n d c a l c u l a t e d r e s u l t s a r e g i v e n i n T a b l e I I I - 6 . 3 . 2 . 2 . 2 . E x p e r i m e n t s c o n c e r n i n g d i s s o c i a t i o n o f p h o s p h i n e l i g a n d s . T h e m e t h o d o f a n a l y z i n g t h e d a t a i n t h e s e p h o s p h i n e d i s s o c i a t i o n e x p e r i m e n t s i s a v a r i a t i o n o f o n e d e s c r i b e d b y D r a g o 9 5 , a n d i n v o l v e s g r a p h i c a l a n a l y s i s . Two s e t s o f c a l c u l a t i o n s w e r e d o n e f o r e a c h s e t o f d a t a f o r t h e t w o p o s s i b i l i t i e s : R u X 2 P 3 , R u X 2 P 2 + P ^ 3 * 3 ^ 2 R u X 2 P 3 ^ ' » R u X 2 P 2 2 + 2 P U s i n g t h e same c o n v e n t i o n s d e s c r i b e d p r e v i o u s l y , a n d m a k i n g t h e a p p r o p r i a t e s u b s t i t u t i o n s , t h e e q u i l i b r i u m e x p r e s s i o n s c a n b e d e r i v e d i n t e r m s o f a b s o r b a n c e m e a s u r e m e n t s : i [ ^ x 2 P 2 ] [ p ] f [ R u X 2 P 3] ( 3 . 2 0 ) -57-A - A 00 A - A 00 [ [ R u X 2 P 2 ] 2 ] [ P ] [RuX 2P 3]' [Ru ]n A - A 00 A - A . 0 0 o [ R ] a + [Ru] T A - A l " [ R u ] T 0 A - A 00 (3.21) (3.22) (3.23) S i n c e , f o r a g i v e n e x p e r i m e n t , [ R u ] , p , [ R ] a > a n d & m a r e a l l k n o w n a n d c o n s t a n t , w h e r e a s v a l u e s f o r K a n d A a r e u n k n o w n ( b u t o c o n s t a n t ) , c a l c u l a t e d v a l u e s o f a n d K 2 a r e o b t a i n e d b y s y s t e m a t i c a l l y s u b s t i t u t i n g a s s u m e d v a l u e s f o r A q . E a c h d a t a p o i n t i s t r a n s f o r m e d i n t o a c u r v e o f K ( c a l c u l a t e d ) v s . A Q ( a s s u m e d ) . T h e s e a r e p r e s e n t e d i n F i g u r e s 3.2, 3.3, 3.5, 3.6, 3-8, -and 3.9. 3.2.2.3. D e t e r m i n a t i o n o f b y J o b ' s m e t h o d 9 3 , 9 I + T h e d a t a f o r t h e s e e x p e r i m e n t s a n d t h e r e s u l t s o f t h e c a l c u l a t i o n s c a n b e f o u n d i n s e c t i o n 3*3 V'(^l 7gur .es 3.-10 'and-?3it1:";an-d-:-Table-III-A).. T h e p r o d u c t s t o i c h i o m e t r y w a s f o u n d b y u s i n g a p l o t o f Y- v s . m o l e r a t i o o f c h l o r i d e , w h e r e Y = t h e d i f f e r e n c e o f t h e a b s o r b a n c e v a l u e s a t a g i v e n [ R u ] ^ w h e n t h e r u t h e n i u m s t o c k s o l u t i o n w a s d i l u t e d w i t h n e a t DMA a n d DMA c o n t a i n i n g 1.24. x 10 M c h l o r i d e , i o n - ( F i g u r e s 3.10, 3.11). T h e f o r m a t i o n c o n s t a n t s K a n d K c w e r e a l s o d e t e r m i n e d u s i n g 4 J t h e d a t a i n T a b l e I I I - 5 . T h e - d a t a f o r t h e d i l u t i o n o f t h e r u t h e n i u m -58-stock s o l u t i o n w i t h DMA obeyed Beer's Law (column 2) and were subjected to a l e a s t squares a n a l y s i s to give the values i n column 3. Those values i n column 4 (absorbance when ruthenium s o l u t i o n was d i l u t e d w i t h CI s o l u t i o n ) which were not d i r e c t l y measured were obtained from the curve i n Figure 3.10 . . The .difference curve a r i s i n g from these two columns i s presented i n Figure 3..1.1-. At low r a t i o s of -[Ru] rj 1/([C1 ] + [Ru]) e s s e n t i a l l y a l l of the complex e x i s t e d as RUgCl^P^ . The i n i t i a l p o i n t s i n Figure 3.11 form a s t r a i g h t l i n e , which i s a Beer' Law p l o t - f o r t h i s complex r e l a t i v e to that of [RuClgPgJg.. This s t r a i g h t l i n e was e x t r a p o l a t e d f o r the absorbance (at high [CI ]) to higher ruthenium concentrations. S u b j e c t i n g the f i r s t s i x p o i n t s of Table I I I - 4 to l e a s t squares' a n a l y s i s ( f o r absorbance d i f f e r e n c e vs. volume ruthenium s o l u t i o n ) gave a slope of -2 -2 -9.44 x 10 , an i n t e r c e p t of 2.37 x 10 . and r e g r e s s i o n constant of 0.9999. The ..experimental'' d e v i a t i o n s from t h i s c a l c u l a t e d l i n e a r i t y at higher [Ru]/([Ru] + [Cl~]) r a t i o s r e f l e c t e d the l a r g e r concentrations of [RuClgPgjg species. Values f o r and were c a l c u l a t e d by l e t t i n g A Q = 0 = absorbance of [RuClgPgJg: A^ = absorbance of RUgCl^P^ (from e x t r a p o l a t i o n of the l e a s t squares a n a l y s i s ) and A = measured absorbance d i f f e r e n c e . The data were analyzed i n terms of two e q u i l i b r i a by the methods discussed p r e v i o u s l y i n S e c t i o n 3.2.2.1. (a) 2 R u C l 2 P 2 + CI" R U g C l ^ " (3.8) [ R u 2 C l 5 P ^ " ] ^4 = (3.24) [ R U C I 2 P 2 ] 2 [ C l " j -59-( b ) R u 2 C l P + C l " R u 2 C l 5 P 4 - (3.7) [ R u 2 C l 5 P ^ ] [ R u 2 C l P ]"[C1"] (3.25) 3 . 2 . 3 . J'P{'H}-N.m.r. s t u d i e s A l t h o u g h DMA f r e e z e s a t - 2 0 ° C , b y u s i n g a m i x e d s o l v e n t s y s t e m ( D M A r t o l u e n e = 0 . 3 t o 0.6) i t was p o s s i b l e t o e x t e n d t h e l o w t e m p e r a t u r e l i m i t t o - 7 0 ° C . T h e r e p o r t e d o b s e r v a t i o n s w e r e i n d e p e n d e n t o f t h e e x a c t s o l v e n t c o m p o s i t i o n w i t h i n t h i s r a n g e . [ R u C l 2 P 2 ] 2 a n d R u C l ^ ( P = P P h ^ P t o l 3 1 > ' 3 3 ) s h o w e d i d e n t i c a l s p e c t r a l f e a t u r e s f o r t h e b i s ( ; p h o s p h i n e ) c o m p l e x , b u t i n t h e l a t t e r c a s e , r e l a t i v e s i g n a l i n t e n s i t y w a s m u c h r e d u c e d b e c a u s e o f c o m p e t i n g c o n t r i b u t i o n s o f : t h e t r i s ( p h o s p h i n e ) s p e c i e s . T h 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 R u C l g P ^ w e r e i d e n t i c a l i n t h i s m e d i u m - a n d i n t o l u e n e , i n d i c a t i n g l i t t l e , i f a n y , s o l v e n t (DMA) i n t e r a c t i o n w i t h t h e t r i s s p e c i e s . T h e s p e c t r u m o f ' - R u ^ C l ^ . ( a c e t o n e ) ( P P n ^ ) , ^ w a s o b t a i n e d b y d i s s o l v i n g [ R u G l ~ ( " P P h 3 > 2 ' ] 2 i n - C D C i ^ / a c e t b n e ' ' f o l l o w e d b y i m m e d i a t e " d a t a a c c u m u l a t i o n . D u r i n g t h e s t u d y , s i g n i f i c a n t a m o u n t s o f s o l i d [ R u C l ^ P P h ^ ) 2 ( a c e t o n e ) ] p r e c i p i t a t e d , b u t a g o o d s p e c t r u m w a s n o n e -t h e l e s s o b t a i n e d . B e c a u s e o f s o l u b i l i t y r e q u i r e m e n t s , t h e P { H } - n . m . r . o f t h e c o r r e s p o n d i n g b r o m o c o m p l e x , R u B r ^ P P h ^ ) ^ , was o b t a i n e d f r o m C D 2 C 1 2 o r C D 0 C 1 0 : D M A (1:1.6 v / v ) m i x t u r e s . -60-3.3 R e s u l t s . T h 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 a d d i t i o n o f t r i p h e n y l -p h o s p h i n e t o s o l u t i o n s o f R u C l ( P P h _ 0 a n d R u B r 0 ( P P h 0 ) 0 i n t o l u e n e <• i 3 i i i a r e g i v e n i n F i g u r e s 3 . 1 a n d 3 . 4 . T h e c o r r e s p o n d i n g d a t a a r e g i v e n i n T a b l e s I I I - 1 a n d I I I - 2 , a n d t h e r e s u l t s o f t h e c a l c u l a t i o n s d e s c r i b e d i n S e c t i o n 3 . 2 . 2 . 2 a r e p r e s e n t e d g r a p h i c a l l y i n F i g u r e s 3 . 2 , 3 . 3 » 3 . 5 a n d 3 . 6 . F r o m t h e s e p l o t s , t h e v a l u e s f o r a t 3 0 ° C f o r t h e r e a c t i o n : K t o l 2 R u X 2 P 3 „ [ R u X 2 P 2 ] 2 + 2P w e r e f o u n d t o b e ( 1 . 1 ± 0 . 5 ) x 1 0 ~ 3 M ( R u C l 2 ( P P h 3 ) ) a n d ( 2 . 1 ± 0 . 6 ) x 1 0 " 3 M ( R u B r 2 ( P P h 3 ) 3 ) . I n D M A , t h e same d a t a a r e p r e s e n t e d i n F i g u r e s 3 . 7 - 3.1 2 _ a n d T a b l e s I I I - 3 t o I I I - 7 . T h e m e t h o d o f d a t a a n a l y s i s u s e d I n t h e s e p h o s p h i n e d i s s o c i a t i o n s t u d i e s w a s a v a r i a t i o n . o f o n e p r e v i o u s l y d e s c r i b e d . I n c a s e s w h e r e o n e o f t w o l i m i t i n g s p e c t r a i s n o t k n o w n , i t i s a l w a y s n e c e s s a r y t o p r e - s u p p o s e a n e q u i l i b r i u m e x p r e s s i o n a n d r e l y o n a p p r o x -i m a t i o n m e t h o d s t o d e t e r m i n e b o t h t h e s e c o n d a b s o r b a n c e v a l u e a n d K . I d e a l l y , a g i v e n s y s t e m s h o u l d h a v e u n i q u e v a l u e s f o r C q a n d K , s o t h a t i f a s e r i e s o f i d e a l d a t a p o i n t s , i s t r a n s f o r m e d i n t o a s e r i e s o f c u r v e s o f K , -, • , , v s . A _ . , , . e a c h c u r v e s h o u l d i n t e r s e c t a t c a l c u l a t e d — o , a s s u m e d a common p o i n t , t h a t b e i n g t h e a c t u a l v a l u e s o f K a n d A . P r a c t i c a l l y , h o w e v e r , e x p e r i m e n t a l e r r o r s t e n d t o c a u s e some s c a t t e r a b o u t t h i s p o i n t . I n t h e p r e s e n t s y s t e m s , v a r y i n g d e g r e e s o f s c a t t e r a r e o b s e r v e d , t h i s p r o b l e m - b e i n g f a r m o r e . ' a c u t e i n ' t h e : R u C l ' 2 ' ( . E P h 3 ) ' 3 _ / D M A ' : s y s t e m . . A n - 6 1 -TABLE I I I - 1 . S p e c t r a l changes at 4-80 nm 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 2 ( P P h 3 ) 3 i n toluene a t 30°C: [Ru.] T = 1.33 X 10~ 3 M (Figure 3.1). 10 3 x [ P P h J , M Abs (4.80. nm) 10 3 x [PPh,l , M Abs (4-80 nm) 0.00 0.98 1.98 1.38 0.176 1.03 2,54 1.43 0.349' 1 .09 3.56 1 .50 0.685 1,15 4.85 1.54 1.008 1.23 17.8 1.65 1.78 1.31 TABLE I I I - 2 . S p e c t r a l changes at 475 nm accompanying the a d d i t i o n of PPh 3 to s o l u t i o n s of RuBr 2(PPh' 3) 3 i n toluene at 30°C; [ R u ] T = 1,38 x 1 0 - 3 M (Figure 3.4). 10 3 x [ P P h 3 ] a , M Abs (475 nm) 10 3 x [ P P h 3 ] & , M Abs (475 nm) 0.70 1.12. 3.31 1.44 1.03 1,17 5.46 1.55 1.35 1.23 7.28 1 . 6 2 1.82 1.29 18.2 1.70 2.60 1.37 3 5 0 4 0 0 5 0 0 6 0 0 7 0 0 W a v e l e n g t h , n m . A b s o r b a n c e c h a n g e s 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 2 ( P P h 3 ) 3 i n t o l u e n e a t 3 0 ° C ; [ R u ] T = 1 . 3 3 x 1 0 " 3 M , 1 0 3 x [ ? P h 3 ] a d d e d = 0 ( A ) , 0 . 1 7 6 ( B ) , 0 . 3 4 9 ( G ) , 0 . 6 8 5 ( D ) , 1 . . 0 0 8 ( E ) , - 1 . 7 8 0 ( F ) , 1 . 9 7 8 ( G ) , 2 . 5 4 3 ( H ) , 3.236(1), 3.560(J), 4 . 8 5 5 ( K ) . „ 1 7 . 8 0 ( L ) , ( T a b l e I I I - 1 ) . -63-0.8 0.6 0.4 0.2 0.0 A q , a s s u m e d . F i g u r e 3.2 P l o t s o f ( c a l c u l a t e d ) v s . A q ( a s s u m e d ) f o r t h e d i s s o c i a t i o n o f R u C l 2 ( P P h 3 ) 3 i n t o l u e n e a t 3 0 C , a s s u m i n g 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 , R u C l 2 ( P P h 3 ) 2 ( a c c o r d i n g t o e q u a t i o n 3 . 2 1 , u s i n g t h e d a t a f r o m T a b l e I I I - 1 ) . -64-0 . 8 0 . 6 0 . 4 0 . 2 0 . 0 A , a s s u m e d . o F i g u r e 3 . 3 P l o t s o f ( c a l c u l a t e d ) v s . A q ( a s s u m e d ) f o r t h e d i s s o c i a t i o n o f R u C l ^ P P h ^ ) ^ i n t o l u e n e a t 3 0 ° C , a s s u m i n g a d i 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 ^ ) 2 ] 2 ( a c c o r d i n g t o e q u a t i o n 3 . 2 3 , u s i n g t h e d a t a f r o m T a b l e I I I - 1 ) . -65-F i g u r e 3.4 A b s o r b a n c e c h a n g e s 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 J 0 i n t o l u e n e a t 30°C ; [ R u l m = < 3 i L J 1 1.38 x 10" 3 M, 10 3 x [ P P H 3 J A D D E D = ° ( A ) , 0 . 7 0 0 ( B ) , 1.03 ( C ) , 1.35 ( D ) , 1 . 8 2 ( E ) , 2.60 ( F ) , 3.31 (G) , 3.64 (H) , 4 . 9 6 ( l ) , 5.46(J), 7.28(K), 9 .10(L) , 1 . 8 2 ( M ) ( T a b l e I I I - 2 ) . -66-0.80 0.60 0.40 0.20 0.00 A , assumed o Figure 3.5 P l o t s of ( c a l c u l a t e d ) vs. A Q (assumed) f o r the d i s s o c i a t i o n of RuB^tPPh.^^ i n toluene at 30°G, assuming a monomeric b i s (phosphine) s p e c i e s , RuB^tPPh.^)^ (according to equation 3.21, u s i n g the data from Table I I I - 2 ) . -67-1 . 0 0 . 8 0 . 6 0 . 4 0 . 2 0 . 0 A , . a s s u m e d , . g u r e 3.6 P l o t s o f K n ( c a l c u l a t e d ) v s . A ( a s s u m e d ) f o r t h e d i s s o c i a t i o n <• — o o f R u B r 2 ( P P h 3 ) 3 i n t o l u e n e a t 30°C, a s s u m i n g a d i 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 B r 2 ( P P h . j ) 2 ] ^ ( a c c o r d i n g t o e q u a t i o n 3.23, u s i n g t h e d a t a f r o m T a b l e I I I - 2 ) . -68-T A B L E I I I - 3 . S p e c t r a l c h a n g e s a t 4-78 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 2 ( P P h 3 ) 3 i n DMA a t 3 0 ° C ; [ R u ] T = 1 . 2 9 X 1 0 - 3 M ( F i g u r e 3 . 7 ) . 1 0 3 x [ P P h ] , M A b s ( 4 7 8 nm) 1 0 3 x [PPh-1 , M A b s ( 4 7 8 nm) j a _______ 3 a_ 0 . 0 0 1 . 1 8 6.65 1.31 1.11 1 . 1 9 9.53 1.36 2.32 1.24 15 .05 1.38 3.94 1 . 2 7 95.3 1.42 4-54 1.29 3 5 0 7 0 0 7 5 0 W a v e l e n g t h , nm F i g u r e 3 . 7 A b s o r b a n c e c h a n g e s 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 3 t o s o l u t i o n s o f R u C l 2 ( P P h 3 ) 3 i n DMA a t 3 0 ° C ; ,-3 [ R u ] _ = 1 . 2 9 x 1 0 " ^ M ( T a b l e I I I - 3 ) . -69-A q , assumed. Figure 3.8 P l o t s of (calculated) vs. A. (assumed) f o r the d i s s o c i a t i o n of R u C l ^ P P h . ^ i n DMA at 30°C, assuming a monomeric bis(phosphine) product, R u C l 2 ( P P h 3 ) 2 (according to equation 3.21, using the data from Table III-3). Figure 3.9 Plots of K p (calculated) vs„. A (assumed) for the dissociation of RuCT 2(PPh 3) 3 in DMA at 30°C, assuming a dimeric bis (phosphine) product, [RuCl^PPh^) 2] 2 (according to equation 3.23, using the data from Table III-3). - 7 1 -T A B L E 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 ( F i g u r e s 3 . 1 0 , 3 . 1 1 ) ; 4 [ R u C l 2 ( P P h - ) - _ ; } A = 1 . 2 4 x 1 0 " 3 M , , [ A s P h C 1 . 2 H 2 0 ] . _ = 1 . 2 5 x 1 0 ~ 3 M : C o l u m n 1 - v o l u m e (mL) ' s t o c k s o l u t i o n A p e r 5 . 0 mL t o t a l . C o l u m n 2 - a b s o r b a n c e f o r B e e r ' s L a w p l o t w h e n s t o c k s o l u t i o n A d i l u t e d w i t h D M A . C o l u m n 3 - c a l c u l a t e d v a l u e s f o r B e e r ' s L a w p l o t b a s e d o n d a t a i n c o l u m n 2 , a c c o r d i n g t o A b s = 0 . 2 1 0 5 ( m L A ) + 6 . 6 1 x 1 0 ~ 2 ; r 2 = 0 . 9 9 7 4 ( s e e s e c t i o n 3 . 2 . 2 . 3 ) . C o l u m n 4 - a b s o r b a n c e w h e n - s t o c k s o l u t i o n A w a s d i l u t e d w i t h s t o c k s o l u t i o n B t o make 5 . 0 m L . C o l u m n 5 - d i f f e r e n c e b e t w e e n c o l u m n s 3 a n d 4. V o l u m e A A b s (4-78 nm) A b s ( c a l c ) A b s ( C l " ) D i f f e r e n c e 0 . 0 0 , 0 5 8 0 . 0 6 6 0 , 0 9 0 + 0 . 0 2 4 0 , 2 - 0 . 1 0 8 0 . 1 1 3 0 . 0 0 5 0 . 5 0 , 1 6 9 ' 0 , 1 7 1 0 . 1 4 7 -0.024 0 , 8 - 0 , 2 3 4 0 , 1 8 2 - 0 . 0 5 2 1 . 0 0 . 2 6 0 • 0 , 2 7 6 0 . 2 0 5 - 0 . 0 7 1 1 . 2 - 0 . 3 1 9 0 . 2 3 0 - 0 . 0 8 9 1 . 5 0 . 3 9 2 0 , 3 8 2 0 . 2 6 8 - 0 . 1 1 4 1 . 8 - a . 4 4 5 0 . 3 0 8 - 0 . 1 3 7 2 . 0 0 . 4 9 0 0 . 4 8 7 0 . 3 5 5 - 0 . 1 5 2 2 . 2 - 0 . 5 2 9 0 , 3 5 9 - 0 . 1 7 0 2 . 5 0 . 6 2 4 0 . 5 9 2 0 . 4 0 8 - 0 . 1 8 4 2 . 8 - 0 , 6 5 5 0 . 4 5 8 - 0 . 1 9 7 3 . 0 0- .685 0 . 6 9 7 0 . 4 9 0 - 0 . 2 0 7 3 . 2 - 0.740 0 . 5 2 7 - 0 . 2 1 3 3 . 5 0 . 8 0 8 0 . 8 0 3 0 . 5 9 6 - 0 . 2 0 7 3 . 8 0 . 8 7 2 0 , 8 6 6 0 , 6 8 5 - 0 . 1 8 1 --72-T a b l e I I I - 4 ( c o n t i n u e d ) . V o l u m e A A b s (4.78 nm) A b s ( c a l c ) A b s ( C l ~ ) D i f f e r e n c e 4 . 0 0 . 9 0 0 0 . 9 0 8 0 . 7 3 3 - 0 . 1 7 5 4 . 2 0 . 9 0 2 0 . 9 5 0 0 . 7 9 0 - 0 . 1 6 0 4 . 4 1 . 0 1 2 0 . 9 9 2 0 . 8 6 7 - 0 . 1 2 5 4 . 5 - 1 . 0 1 3 0 . 9 0 3 - 0 . 1 1 0 4 . 6 1 . 0 5 1 1 . 0 3 4 0 . 9 4 3 - 0 . 0 9 1 4 . 8 1 . 0 4 4 1 . 0 7 6 1 . 0 2 0 - 0 . 0 5 6 4 . 9 1 . 1 1 0 1 . 0 9 7 1 . 0 7 0 - 0 . 0 2 7 5 . 0 1 . 1 1 2 1 . 1 1 8 1 . 1 1 2 - 0 . 0 0 6 T A B L E 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 _ , f o r R u „ C l _ ( P P h _ ) " u s i n 4 5 2 5 3 4 t h e d a t a i n T a b l e I I I - 4 . V o l u m e A * , m L 10^ x [RuL, M 10 - 7 X K _ , M - 2 10~^ X K , , M - 1 i ~ D ~ / — 1- 8 4.46 64.6 3.06 2- ° 4-96 39.2 2.66 2-2 5.46 44.8 3.22 2.5 6.20 14.5 2.14 2 . 8 6.94 8.8 1.99 3.0 7.93 7.8 2.69 2 . 5 8 ± 0.46 C o l u m n 1, T a b l e I I I-4. - 7 3 -0 - 2 0 . 4 0 . 6 0 . 8 V o l u m e r u t h e n i u m s o l u t i o n / t o t a l v o l u m e . i g u r e 3 . 1 0 P l o t s o f a b s o r b a n c e v s . r u t h e n i u m c o n c e n t r a t i o n w h e n DMA s o l u t i o n s o f R u C l 2 ( P P h 3 ) 3 ( [ R u ] T = 1 . 2 3 x 1 0 - 3 M) w e r e d i l u t e d w i t h DMA ( 0 ) a n d DMA s o l u t i o n s o f A s P h ^ C 1 . 2 H 2 0 ( [ C l ] = 1 . 2 4 x 1 0 " 3 M; v ) a t 3 0 ° C . 0.0 , , — i r i 1— 3 5 0 4 0 0 5 0 0 6 0 0 W a v e l e n g t h , n m . F i g u r e 3 . 1 2 A b s o r b a n c e 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 g i v e n 2 R u C l 2 ( P P h 3 ) 3 + C I " «, * R u 2 C l 5 ( P P h 3 ) ^ , " + 2 P P h 3 i n DMA a t 3 0 ° C ( T a b l e I I I - 6 ) . - 7 6 -T A B L E I I I - 6 . D e t e r m i n a t i o n o f K g ( F i g u r e 3.12): [ R u C l _ . ( P P h - ) 3 ] _ = 1 .06 x 1 0 - 3 M , [ A s P h C1..2H_0] = 2.03 x 1 0 - 3 M . : [ P P h - . l ... M L 3 J a — A b s (484 nm) ( I / T I ) : 10^ x [ l l ] , M K 6 0 O.466 0 1 0 , 6 -4 . 0 0 0.546 0 . U 5 5 9 . 3 9 5 0 0 6 . 6 0 0 , 5 8 3 0 . 2 2 8 8 . 8 3 5 0 4 10.0 0 .61.6 0 , 2 7 3 8 . 3 3 5 8 7 1 2 . 5 O.646 O..346 7.84 5 7 2 1 6 . 7 0 . 6 8 6 0 , 4 5 8 7 . 2 7 5 9 7 20 , 0 0 , 7 2 6 0, 591 6 . 6 6 541 20,0 0 , 7 3 5 O..624 6 . 5 3 4 9 2 2 6 . 7 0 . 7 8 1 0 . 8 1 8 5 . 8 3 5 4 9 30.8 0 , 8 1 1 0 . 9 7 2 5 . 3 6 5 4 9 36,4 0 , 8 5 7 1 . 2 6 5 4.68 5 0 5 44.4 0 . 8 9 4 1 . 5 7 4 4 . 1 2 5 4 0 50.0 0 . 9 2 0 1 .84.5 3 . 7 3 5 4 2 57.1 0.946 2 , 1 8 3 . 3 3 5 5 8 6 6 , 7 0 . 9 7 6 2 . 6 8 2.88 5 7 4 71.4 0 . 9 8 7 2 . 9 1 2 . 7 1 5 9 0 1 . 1 6 6 _ _ _ M e a n 54-5 * - S e e t e x t . - 7 7 -T A B L E I I I - 7 . S p e c t r a l c h a n g e s a t 6 1 0 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 B r 2 ( P P h 3 ) 3 i n DMA a t 3 0 ° C ; [ R u ] _ = 1 . 3 6 x 1 0 ~ 3 M . 1 0 3 x [ P P h 3 ] a > M ADS* (610 nm) 1 0 3 x [ P P h - ] . , M A b s * ( 6 l 0 nm) 0 . 0 0 0 . 4 6 3 9 . 8 8 0 . 3 6 5 1 . 2 4 0 . 4 4 5 12.. 4. 0 . 3 5 0 2 . 4 7 0 . 4 2 8 14 .8 0 . 3 3 1 4 . 9 4 0.402 1 6 . 5 0 . 3 2 7 7 . 4 1 0 . 3 8 0 2 2 . 2 0 . 3 0 5 8 . 9 8 0 . 3 6 7 4 1 . 0 0 . 2 8 0 V a l u e s t a k e n f r o m e x p a n d e d s p e c t r a a n d a r e d i r e c t l y p r o p o r t i o n a l t o a b s o r b a n c e a t t e m p t w a s made t o f i n d t h e e f f e c t o f c e r t a i n v a r i a t i o n s o n v a l u e s f o r K 2 - F o r e x a m p l e , p o i n t 2 f r o m T a b l e I I I - 1 ( r e g a r d i n g t h e d i s s o c -i a t i o n o f R u C l 2 ( P P h 3 ) 3 i n t o l u e n e ) h a s t h e f o l l o w i n g d a t a a s s o c i a t e d w i t h i t : 1 . 3 3 x 1 0 " 3 M ; 1 . 3 1 . F r o m t h e e n t i r e d a t a s e t , A q w a s f o u n d t o b e 0.60 ( F i g u r e 3 . 3 ) a n d _3 t h i s p o i n t g a v e a v a l u e f o r = 1 . 3 0 x 1 0 M u n d e r t h e s e c o n d i t i o n s . T h e e f f e c t s o f s l i g h t v a r i a t i o n s ( e x p e c t e d e r r o r s ) i n m e a s u r e m e n t o f A ^ , A , a n d ( P ] a » w e r e e x a m i n e d a n d . t h e r e s u l t s a r e g i v e n i n T a b l e I I I - 8 . I t i s a p p a r e n t t h a t e v e n s m a l l e r r o r s i n a b s o r b a n c e r e a d i n g s b e c o m e g r e a t l y m a g n i f i e d d u r i n g t h e s e c a l c u l a t i o n s . A l t h o u g h n o t s h o w n Padded = 1 . 7 8 x 1 0 - 3 M ; [ R u ] _ A „ = 1 . 6 5 ; A - 7 8 -T A B L E 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 J , 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 p B. oo o f K ; u s i n g d a t a f r o m T a b l e I I I - 1 ( s e e t e x t ) . x [PPh^]n,M. A b s . . A 00 1 0 3 x K ? c a l c ' d , M V a r i a t i o n 1 . 7 8 1 . 3 1 1 . 6 5 1 . 3 0 _ 1 . 6 9 ( 5 $ ) 1 . 3 1 1 . 6 5 1 . 2 0 1.1% 1 . 8 7 ( 5 $ ) 1 . 3 1 1 . 6 5 1 . 4 1 8.5% 1 . 7 8 1 . 2 8 . ( 2 « • 1 . 6 5 1 . 6 0 23% 1 . 7 8 1 . 3 4 ( 2 $ ) 1 . 6 5 1 . 0 5 1 9 $ 1 . 7 8 1 . 3 1 1 . 6 2 ( 2 $ ) 1 . 1 3 1 3 $ 1 . 7 8 1 . 3 1 1 . 6 8 ( 2 $ ) 1 . 4 9 U . 6 $ d i r e c t l y , t h i s m a g n i f i c a t i o n i s g r e a t e r i n t h e DMA c a s e . B e c a u s e t h e d i f f e r e n c e s i n t h e m e a s u r e d a b s o r b a n c e r e a d i n g s a r e s m a l l e r , a b s o l u t e e r r o r s t a k e o n g r e a t e r s i g n i f i c a n c e . T h e s c a t t e r a p p e a r s t o b e a r e a s o n a b l e r e f l e c t i o n o f t h e e x p e r i m e n t a l l i m i t a t i o n s . T h e r e s u l t s o f t h e c a l c u l a t i o n s o f t h e DMA s y s t e m i n d i c a t e d t h a t v a l u e s c o u l d b e o b t a i n e d f o r t h e f o l l o w i n g e q u i l i b r i a : K ( D M A , X = C I " ) K 2 ( D M A , X = C l " ) K . (DMA) 4 IC ( D M A ) 5 K g ( D M A ) ( 4 . 3 ± 0 . 7 ) x 1 0 " 3 M ( 1 . 5 ± 0 . 5 ) x 1 0 " 2 M ( 2 . 6 ± 0 . 6 ) x 1 0 ^ M " 1 (8 t o 6 5 ) x 1 0 7 M " 2 ( 5 . 5 ± 0 . 5 ) x T O 2 K ( D M A , X =. B r " ) = (7 ± 1) x ^0~3 M -79-K 2 ( D M A , X = B r " ) = ( 5 + 1 ) x 1 0 - 2 M . T h e c a l c u l a t e d e x t i n c t i o n c o e f f i c i e n t s f o r [ R u C T ^ P P h ^ ) 2 ] 2 r e s u l t i n g f r o m t h e p h o s p h i n e d i s s o c i a t i o n s t u d y i n t h i s s o l v e n t (e^^ n m = 8 5 0 -1 -1 M cm ) c o m p a r e d r a t h e r f a v o r a b l y w i t h t h e a c t u a l v a l u e f o u n d f o r s o l i d [ R u C l ^ P P h ^ ) d i s s o l v e d I n DMA b y B e e r ' s L a w a n a l y s i s ( o v e r 1 0 " 4 - t o 1 0 " 3 M , e 4 - 8 0 n m - 8 3 7 M ~ 1 . c m " 1 ) . T h i s l a t t e r p l o t a l s o d e m o n s t r a t e s - t h a t t h e e q u i l i b r i u m i n e q u a t i o n 3 . .26 i s n o t o b s e r v e d . [ R u C l 2 ( P P h 3 ) 2 ] 2 2 R u C l 2 ( P P h 3 ) 2 ( 3 . 2 6 ) T h e P { ; H } - n . m . r . s p e c t r u m o f [ R u G l ^ P P h ^ ) 2 ] 2 i n t o l u e n e h a s b e e n d e s c r i b e d p r e v i o u s l y , 3 5 . There- - was - ' no" e v i d e n c e f o r a s p e c i e s R u 2 C l ^ ( N 2 ) ( P P h 3 ) ^ w h e n s p e c t r a w e r e o b t a i n e d f r o m s a m p l e s o f [ R u C l 2 ( P P h 3 ) 2 ] 2 i n t o l u e n e - d g u n d e r o n e a t m o s p h e r e o f N , . , . T h e v a r i a b l e 31 1 t e m p e r a t u r e P{'' H } - n . m . r . d a t a o b t a i n e d i n D M A / t o l u e n e - d g a r e p r e s e n t e d i n F i g u r e s 3 . 1 3 a n d 3 .14- a n d T a b l e . I l l - 9 . I n t h e t e m p e r a t u r e r a n g e + 5 0 ° C t o + 2 0 ° C , t h e . s p e c t r a o f . [ R u C l 2 ( P P h 3 ) 2 J 2 i n DMA s h o w e d o n l y a b r o a d e n e d s i n g l e t a t 6 6 . 7 p p m . I n t h e r a n g e - 2 0 ° C t o - 7 0 ° C , a l t h o u g h t h i s s i n g l e t i s p r e s e n t , t h e - m a j o r s p e c i e s i n s o l u t i o n (>90% o f i n t e g r a t e d i n t e n s i t y ) w a s o n e c o n t a i n i n g t w o i n d e p e n d e n t A B s y s t e m s -( d e s i g n a t e d A B a n d C D ) . E a c h d o u b l e t i n t e g r a t e d . t o . 2 5 $ o f t h e t o t a l o f t h e s y s t e m . T h e s p e c t r a l p a r a m e t e r s , a n d r e l a t i v e i n t e n s i t i e s w e r e i n d e p e n d e n t o f t h e e x a c t c o m p o s i t i o n o f t h e s o l v e n t s y s t e m , a n d a p p e a r e d t o b e d u e t o a s i n g l e s p e c i e s , r a t h e r . t h a n a m i x t u r e o f c o m p o u n d s . T h e c h e m i c a l s h i f t s v a r i e d , w i t h t e m p e r a t u r e - a n d v a l u e s o f J p p w e r e d e t e r m i n e d a s s u m i n g t h e l a t t e r t o b e i n d e p e n d e n t o f t e m p e r a t u r e . On - 8 0 -30 -10' V I Vfi/u/J 24.0 ppm •20 •40' -60e • 7 0 ' F i g u r e 3 . 1 3 3 1 P { - 1 H } . - N . . m . r s p e c t r a o f Ru^ l^DMA) ( P P h ^ a s a f u n c t i o n o f t e m p e r a t u r e a t 4O.505 M H z . S p e c i e s g e n e r a t e d i n s i t u f r o m [ R u C l 2 ( P P h 3 ) 2 ] 2 i n D M A / t o l u e n e - d 8 ( v / v = 1 : 1 ) ( T a b l e I I I - 9 ). -81-T A B L E I I I - "9. 3 1 P { 1 H } - N . m . . r . p a r a m e t e r s a f o r [ R u C l ^ P P h ^ ) 2 ] _ i n t o l u e n e a n d D M A b . ( i ) " t o l u e n e - d g J ^ = 4 .2 .5 H z . T e m p e r a t u r e , G _ P A . _ _ P B _ -20 59.7 52.2 -40 60,0 52.4 -60 60.2 52.5 ( i i ) D M A / t o l u e n e - d D o ( v / v =1:1) J A B = 29.9 H z , J C D ~ T e m p e r a t u r e , °C _ P A P B P r P P -10 50.06 48 .55 43 .07 42.39 -20 50.68 48 .61 42.92 42.51 -40 51.4-8 48 .61. 42.69 42.60 -60 52,34 48. .46' 42.64 42.39 - 7 0 52.88 48 .34 42.67 4-2 • 22 36.8 H z . a C h e m i c a l s h i f t s a r e i n ppm d o w n f i e l d f r o m 85% H P O . . 3 4 b I n t h i s s o l v e n t , [ R u C l ^ ' P P h . ^ ] _ e x i s t s a s R u 2 C l ^ ( D M A ) ( P P h ^ ) . - 8 2 -• 20 - 4 0 • 5 0 ' - 6 5 1 -15" J VL 31 1 F i g u r e 3 - U P { H } - N . m . r . s p e c t r a o f R u o 0 1 - ( P P h J ~ i n D M A / t o l u e n e - d r <• 5 3 4 £ ( v / v = 1 : 1 ) a s a f u n c t i o n o f t e m p e r a t u r e a t 4 0 . 5 0 5 MHz ( T a b l e 1 1 1 - 1 1 ) . - 8 3 -a d d i n g c h l o r i d e i o n ( a s t h e L i + o r A s P h + s a l t ) t o t h e s o l u t i o n , t h e s e 4 s i g n a l s w e r e r e p l a c e d b y t h e p a t t e r n s s h o w n i n F i g u r e 3 . 14. When R u C l ^ P ^ ( P = P P h ^ , P t o l ^ ) .was, u s e d a s t h e r u t h e n i u m s o u r c e , a n a d d i t i o n a l r e s o n a n c e ( a t c a . - 5 ppm) d u e t o P P h 0 o r P t o l - w a s o b s e r v e d 5 5 w i t h t h e e x p e c t e d i n t e n s i t y . A s t h e t e m p e r a t u r e o f t h e s o l u t i o n w a s l o w e r e d , t h e r e w a s a n a p p a r e n t s l i g h t u p f i e l d s h i f t o f t h e s i g n a l ( s ) . A l t h o u g h i t b e c a m e e v i d e n t a s s u c h o n l y a t t e m p e r a t u r e s b e l o w - 5 0 ° C , e a c h s p e c t r u m c a n b e d e s c r i b e d a s a n A B p a t t e r m w i t h d i f f e r e n t v a l u e s f o r J / A 6 . T h i s d i f f e r e n c e i n J / A 6 r e s u l t e d f r o m t h e t w o p h o s p h i n e r e s o n a n c e s h a v i n g b e e n s h i f t e d , t o d i f f e r e n t d e g r e e s o n l o w e r i n g t h e t e m p e r a t u r e . I n c o n t r a s t t o t h e c h l o r o s y s t e m , t h e c o r r e s p o n d i n g [ R u B r ( P P h ) 9 ] „ 3*1 *1 i s n o t k n o w n , s o P { H } - n . m . r . s t u d i e s w e r e l i m i t e d t o u s i n g t h e s p a r i n g l y s o l u b l e R u B r g ^ P P h ^ ) _ . . I n . C D ^ C l ^ , a t - 5 0 ° C , i n a d d i t i o n t o s i g n a l s a s s i g n a b l e t o t h e - t r i s ( ' p h o s p h i n e ) s p e c i e s . ' - ( b r o a d , 31 ppm) a n d . P P h ^ ( - 7 . 0 ppm) , t h e r e w a s a n A B p a t t e r n o b s e r v e d a t - 5 0 ° C ( 6 ^ = 6 1 . 3 p p m , 6g= 54- .0 p p m , J p p = 4O H z ) w h i c h w a s ; a s s i g n e d t o [ R - u B r ^ P P h ^ ) ^ ] 2 -T h e p a r a m e t e r s w e r e i n g o o d , a g r e e m e n t w i t h t h e l i t e r a t u r e v a l u e s 6 8 . A f t e r a d d i t i o n o f DMA t o t h e s o l u t i o n , t h e A B p a t t e r n w a s r e p l a c e d b y a s i n g l e t ( - 5 0 ° C , 6 9 . 5 p p m ) . 3 . 4 D i s c u s s i o n . W h e n t r i p h e n y l p h o s p h i n e i s a d d e d t o t o l u e n e s o l u t i o n s o f R u X ^ P P h ^ ) ^ ( X = C l , B r ) , t h e o b s e r v e d s p e c t r a l c h a n g e s w e r e q u a l i t -a t i v e l y i d e n t i c a l w i t h t h o s e o b s e r v e d b y M a r k h a m 6 a f o r t h e ' R u C X ^ X P P h ^ ) o s y s t e m i n b e n z e n e a t 25 C , a n d i n d i c a t e t h e p e r t u r b a t i o n o f t h e -84-e q u i l i b r i u m : n R u X 2 P 3 , - [ R u X 2 P 2 ] n + n P ( 3 . 2 7 ) s o a s t o f o r m t h e trin(phosph:':.r.•?•)' s p e c i e s - . 1 T h e l i m i t i n g s p e c t r a a t -1 -1 h i g h p h o s p h i n e c o n c e n t r a t i o n s s h o w m a x i m a at.480 nm (fe = 1250 M c m " ) -1 -1 a n d 738 nm (e = 514 M cm ) f o r t h e c h l o r o a n a l o g u e a n d a t 497 nm — 1 - 1 - 1 - 1 ( e = 1230 M cm ) a n d 764 nm ( e = 523 M cm ) f o r t h e b r o m o c a s e . T h e f o r m e r v a l u e s a r e i n g o o d a g r e e m e n t , w i t h M a r k h a m ' s v a l u e s o f 48O nm ( e = 1350 M cm" ) a n d 750 nm ( e = 5 1 5 M c m " ' ) . T h e K 2 v a l u e s o b t a i n e d i n d i c a t e t h a t b o t h s y s t e m s a r e - 7 0 $ d i s s o c i a t e d i n t o l u e n e a t 30°C a n d [ R u ] ^ - 10 3 M , - A l t h o u g h t h e b r o m o a n a l o g u e g a v e - 3 a s l i g h t l y l a r g e r v a l u e ((2.1 ± 0.6) x 10" M) t h a n t h e c h l o r o s y s t e m ((1.1 ± 0.5) x 10 M ) , t h e e r r o r a n a l y s i s i n d i c a t e d t h a t t h e t w o a r e w i t h i n e x p e r i m e n t a l e r r o r o f e q u i v a l e n c e . T h e e q u i l i b r i a : 2 R u X 2 P 3 , , [ R u X 2 P 2 ] 2 + 2 T ( 3 . 6 ) c a n b e d i s p l a c e d i n b o t h c a s e s t o t h e r i g h t b y h e a t i n g , i n d i c a t i n g 1 8 t h a t d i m e r f o r m a t i o n i s e n d o t h e r m i c . I n a n a t t e m p t t o u s e M a r k h a m ' s d a t a t o o b t a i n t h e a p p r o p r i a t e c o n s t a n t s a t 2 5 ° C , h i s d a t a ( r e f . 6 a , p . 24 ) w e r e s u b j e c t e d t o i d e n t i c a l t r e a t m e n t . . F i g u r e s 3 . 1 5 a n d 3 . 1 6 s h o w t h e c u r v e s w h i c h r e s u l t w h e n K ^ . ( b e n z e n e ) a n d K 2 ( b e n z e n e ) a r e a s s u m e d . A l t h o u g h i n t h e l a t t e r c a s e - i t i s d i f f i c u l t t o d e t e r m i n e a v a l u e f o r K 2 ( s e e F i g u r e 3 . 1 6 ) , i t a p p e a r s t h a t i t i s v e r y m u c h l a r g e r t h a n t h e v a l u e ( ( 1 . 1 ± 0.5) x 1 0 " 3 M) f o u n d i n t h i s w o r k i n - 8 5 -0 . 6 0 . 3 0 . 0 A , assumed. Figure 3 . 1 5 P l o t of ( c a l c u l a t e d ) vs. A q (assumed) f o r the d i s s o c i a t i o n of R u C l ^ P P h ^ ) ^ i n benzene at 25°C, assuming a monomeric bis(phosphine) product, R u C l g t P P h ^ ) u s i n g the data i n reference 6 a (according to equation 3 . 2 1 ) -86-0.60 . 0^40 .  o'.20 0.00 A , assumed. o gure 3.16 Plot of (calculated) _. A q (assumed) for the dissociati of RuCl^PPh^)^ in benzene at 25°C, assuming a dimeric bis(phosphine) product, [RuCl^PPh^)^^' using the data in reference D a (according to equation 3.23). - 8 7 -t o l u e n e a t 3 0 ° C . T h i s i s r e f l e c t e d i n t h e a m o u n t o f P P h ^ r e q u i r e d t o o b t a i n t h e l i m i t i n g s p e c t r u m f o r R u C l - ^ P h ^ ) - ( M a r k h a m ' s d a t a i n d i c a t e t h a t a l i m i t i n g s p e c t r u m i n b e n z e n e a t 2 5 ° C w a s o b t a i n e d o n l y w h e n [ P ] = 9.24 x .10 - M ; we f i n d t h e l i m i t i n g s p e c t r u m i s o b t a i n e d 2 a t [ p ] = 1 . 8 x 1 0 " 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 t i s d i f f i c u l t a t o " r a t i o n a l i z e - " t h i s ' d i s p a r i t y b u t . , t r a c e p h o s p h i n e o x i d a t i o n c o u l d h a v e g i v e n a n o m a l o u s l y h i g h m e a s u r e d p h o s p h i n e c o n c e n t r a t i o n s i n t h e p r e v i o u s w o r k . U s i n g t h e v a l u e s f o u n d f o r K ^ o J - u e n e j _ n t o l u e n e , i t i s p o s s i b l e t o c a l c u l a t e t h e d e g r e e s o f d i s s o c i a t i o n a t v a r i o u s c o n c e n t r a t i o n s . 31 1 T h e s e a r e c o m p a r e d w i t h some v a l u e s e s t i m a t e d f r o m P { H } - n . m . r . s t u d i e s ( T a b l e 111 - 1 0 ) - , , T h e p r e s e n t d a t a i n d i c a t e m u c h l e s s d i s s o c - . •:• i a t i o n i n t o l u e n e t h a n h a s p r e v i o u s l y b e e n , d e t e r m i n e d . T h e v a l u e s f o r K _ i n c h l o r i n a t e d s o l v e n t s d e t e r m i n e d b y P { . H } - n . m . r . a r e i n r e a s o n a b l e a g r e e m e n t ( ( 2 ± 1.) x 10 ^ M ) , . b u t a r e c o n s i d e r a b l y l e s s t h a n t h e c o r r e s p o n d i n g . v a l u e s , f o u n d i n t o l u e n e a n d b e n z e n e 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 e f a v o r e d s o l v a t i o n o f * t h e d i m e r p r o d u c t a n d e s p e c i a l l y P P h ^ i n t h e a r o m a t i c s o l v e n t , t h r o u g h f t - e l e c t r o n i n t e r a c t i o n s c o u l d a c c o u n t f o r t h e i n c r e a s e d d i s s o c i a t i o n 9 5 . O f g r e a t s i g n i f i c a n c e t o t h i s ; w o r k , h o w e v e r , i s t h e q u a l i t a t i v e d e s c r i p t i o n o f t h e s o l u t i o n c h e m i s t r y o f R u G l ^ P P h ^ ) i n D M A . A s s t a t e d p r e v i o u s l y , t h e s p e c t r a o f t h i s . compound i n t h e a b s e n c e o f a d d e d l i g a n d s i n t o l u e n e a n d DMA a r e v e r y d i f f e r e n t . ( c f . F i g u r e s 3 . 1 a n d 3 . 8 ) . Y e t , a d d i t i o n o f p h o s p h i n e c a u s e d a n a l o g o u s s p e c t r a l c h a n g e s . A l t h o u g h t h e e x t i n c t i o n c o e f f i c i e n t s a t 4 8 0 nm i n t h e h i g h p h o s p h i n e s p e c t r a w e r e c o n s i s t e n t l y l o w e r b y c a . 1 0 $ i n DMA t h a n i n t o l u e n e , t h e s i m i l a r i t y i n t h e f i n a l s p e c t r a , a n d P { ' H . } - n . m . r . e v i d e n c e i n d i c a t e -88-TABLE 111-10. Degree of d i s s o c i a t i o n f o r RuXgCPPh^)^ at .30°C i n toluene as a f u n c t i o n of c o n c e n t r a t i o n a . C o n c e n t r a t i o n ( [R'J j^)..• D i s s o c i a t i o n ' 0 . . D i s s o c i a t i o n 0 Comments^. 10"4- M' 82$. . 88$ t h i s work 10~ 3 M 64$ • 71$ t h i s work TO"2 M 42$'; 4-8$ t h i s work i o - 1 : M ' 24$. 28$ t h i s work 7.6 x.1.0"2 M . 15$ 6 - i n CDC1 3, K 2 = 1.8 x 10"4- M 5 x 10." 2 M 15$ 6 - i n GD 2C1 2, K 2 = 1.2 x 10"4- M i o ^ 2 : M 59$ e - i n toluene, 6.1 x 10" 3 M -2 10 M> 30%? • - K2=2.8 x 10~3 M t o ' 1 .M' 5$ f - K2=6.9 x 10" 6 M a : Given by = ^ X ^ R U V ' , where. 0 < x < 0.5 and (1-2X)(100$) gives ( 1 - 2 X ) 2 percentage..not d i s s o c i a t e d ; unless- otherwise s p e c i f i e d , using the K terms found i n t h i s work, b ' For RuGl 2('PPh 3) 3 ( i n t h i s work K 2 = 1.1 x 10~ 3 M) . c' For R u B r 2 ( P P h 3 ) 3 ( i n t h i s , work K g = 2.1 x 10" 3 M). d' K 2 values c a l c u l a t e d from'-the reported degrees of. d i s s o c i a t i o n , e 1 From- reference 68. ' f From reference 87, 25°C. -89-that under these c o n d i t i o n s the ruthenium e x i s t s s o l e l y as the t r i s -• (phosphine-)',.-speci-as^ -RuGl^PPh-).^. In t h e presence of added c h l o r i d e i o n , the a n a l y s i s i n d i c a t e s the formation of an a s s o c i a t e d complex w i t h Ru:Cl = 2:1. Had the nature of the r e a c t i o n been r e - a s s o c i a t i o n of an i o n i z e d c h l o r i d e i o n , as was i n i t i a l l y suggested, the r e s u l t i n g p l o t of absorbance d i f f e r e n c e vs. volume r a t i o would.have shown no minimum (or maximum). -1 31 1 At higher concentrations, (10 M) the P{ H}-n.m.r. spectra (Figure 3.14-) are c o n s i s t e n t w i t h the s t r u c t u r e ' ( i j ) , i n which l o n g range i n t e r a c t i o n s cause the resonances due to P^ and Pg to be i n s l i g h t l y d i f f e r e n t environments. The chemical s h i f t of these resonances a t higher temperatures are i n e x c e l l e n t agreement with previous r e p o r t s . In the absence of added l i g a n d s , i t appears t h a t R u C l ^ P P h ^ ) ^ i s s i g n i f i c a n t l y d i s s o c i a t e d i n DMA (^88$ at 10" 3M, 95$ at 1 0 - ^ M, 30°C), but the product i s dime r i c . In contrast to the studies i n toluene, the data obtained from the study i n DMA do not d i f f e r e n t i a t e the nature of the phosphine d e f i c i e n t species, and can be analyzed i n terms of a monomer-monomer or- mbnomer-d-i-mer e q u i l i b r i u m : - (IT) K DMA 1 -90-This appears to arise from the different degree of dissociation that occurs in each solvent. However, good evidence for the dimeric nature can be obtained by coupling the 3 measured equilibria. If the analyses for a dimeric bis(phosphine) species are correct, then KJ?MA 2RuCl 2(PPh 3) 3. + CI" =^= Ru 2Cl 5(-PPh 3)^' + 2PPh3 (3-9) K 2 M A 2RuCl 2(PPh 3) 3 ;======= [RuCl 2(PPh 3). 2] 2 + 2PPh3 (3.6) K^ M A [RuCl 2(PPh 3) 2] 2 + CI" ===== Ru 2Cl 5(PPh 3)^" (3.7) K 6 should equal K 2 x K.v = ('(.1.5 ± 0.5) x 10 _ 2M)((2.6 ± 0.5) x 1 o V 1 ) = 390 ± 200. This i s in good" agreement.with the value experimentally found (545 ± 30). Similarly, the possibility:of the monomeric form may be excluded. If this were the, case, the Kg equilibrium'(equation 3.9) 2RuCl 2(PPh 3) 3 + CI" „ Ru 2Cl 5(PPh 3)^" + 2PPh3 (3.9) 2 would consist of the coupling of the K and K_ equilibria: I 5 2 RuCT 2(PPh 3) 3 2 RuGl 2(PPh 3) 2 + 2PPh3 (3.28) and 2 RuCl 2(PPh 3) 2 + Cl" — ^ R u ^ l ^ P P h ^ " (3.8) Because of the variability found for the experimental K values, a 5 2 convenient test i s to calculate this value using Kg and K„ . Thus: K, (545 ±36) 7 2 K = — = = (3 ± D x 1 0 ' M 5 (K ' j 2 [(4.3 ± 0.7) x 10" 3M] 2 (3.29) -91-8 7 - 2 This value i s outside the range found f o r K 5 (6.4 x 10 t o 8 x 10 M ) and serves to eliminate- a monomer complex as a major bis-phosphine species i n DMA. Because the v i s i b l e spectra of RuCl^PPh^) (or [ R u C l ^ P P h ^ ) 2 ] 2 ) are d i s s i m i l a r i n toluene and DMA, although the complex i s dimeric i n each, one must invoke some solvent i n t e r a c t i o n i n the l a t t e r case. 31 1 P{ H}-N.m.r. spectra give e x c e l l e n t i n f o r m a t i o n as t o the nature of t h i s i n t e r a c t i o n . The spectra observed.(Figure 3-13) a l s o i n d i c a t e a dimeric species, i n which the two ..-.ends of the u n i t are d i f f e r e n t . This i s most e a s i l y r a t i o n a l i z e d . b y a t r i p l y chloro bridged species, s i m i l a r to the pentachloroanionic. .dimer discussed p r e v i o u s l y , i n which only one DMA has entered the coordination, sphere* = DMA ( I I I ) The peak observed at .66.7.ppm (Figure 3.13) has been p r e v i o u s l y assigned to the species.RuCl^PPh^) 2 ( D M A ) 2 ? a ' 3 5 . .; I t s r e l a t i v e i n t e n s i t y v a r i e s with ruthenium source,, and the peak i s . not evident i n the spectra of R u C l ^ P P h . ^ . or Ru' 2Cl 5(PPh 3) ' . An e q u i l i b r i u m of the form':" Ru 2Cl^(PPh 3) 4(DMA) .+.. DMA.. - - 2 RuGl^PPh^) 2(DMA) 2 (3.30) would be more.detectable at lower concentrations, but. the v i s i b l e s p e c t r a l -92-s t i i d i e s on R u C l ^ P P h ^ ) ^ or [ R u C L ^ P P h ^ ) 2 ] 2 i n DMA gave no evidence f o r t h i s ( S e c t i o n 3.2.2). I t i s impossible to i d e n t i f y such a s i n g l e t species, unless an authentic sample i s a v a i l a b l e , f o r comparison. However, i n . v i e w f o f the .apparent propensity of ruthenium to form t r i p l y chloro bridged dimers ( v i d a i n f r a ) , i t i s p o s s i b l e t h a t the s i g n a l to i s due to a fragment of the form: / C l / C l \ ^ .DMA — C l l/l/ii^Ru^—iDMA or — C l mum. Ru '-—-DMA ^ C l ' ^ P P h 3 ^ C l ' ^ P P h -(IV), (V) • I t was of i n t e r e s t to compare the r e s u l t s of t h i s work i n DMA q u a n t i t a t i v e l y w i t h those . of. Markham. Because ..of experimental design though, only one set of experimental c o n d i t i o n s he used a l l o w d i r e c t comparison, t h a t being the r e a c t i o n w i t h c h l o r i d e i o n . Markham's data (Reference 6a, Table I I I ) can be presented i n the g r a p h i c a l method-of mole r a t i o s 9 3 , where the concentration of one reagent i s f i x e d ( i n t h i s case, ruthenium), and the second ( c h l o r i d e ) i s v a r i e d . A p l o t of absorbance vs. the mole rati© of the reactants (Figure 3.17), i f the formation constant i s reasonably ..favorable, y i e l d s two l i m i t i n g s t r a i g h t l i n e s at high and low l i g a n d concentrations. The i n t e r s e c t i o n of the two l i n e s corresponds to the.combining r a t i o . o f . the complex. Since i t i s now known that the stoichiometry of the complex i s 2Ru:1Cl , the l i n e s should meet at the r a t i o 0.5- The data i n d i c a t e an i n t e r s e c t i o n at -0.70 and imply that the added c h l o r i d e i o n concentration i s i n e r r o r by 35%. Markham used l i t h i u m c h l o r i d e as 0.95 t h e s o u r c e o f c h l o r i d e i o n , b u t u n f o r t u n a t e l y i t s e x t r e m e l y h y d r o -s c o p i c n a t u r e c a u s e s i t t o o c c l u d e v a r i a b l e a m o u n t s o f w a t e r d u r i n g h a n d l i n g . A l t h o u g h M a r k h a m ' s d a t a s u g g e s t m u c h l e s s c h l o r i d e a s s o c -i a t i o n t h a n d o t h e p r e s e n t d a t a , t h e u n d e t e c t e d d e c r e a s e i n e f f e c t i v e c h l o r i d e i o n c o n c e n t r a t i o n c a u s e d b y o c c l u d e d w a t e r c o u l d a c c o u n t f o r t h i s d i f f e r e n c e . T h e m a i n s o l u t i o n s t r u c t u r e s ( I I " ' a r i d ' . I l l ) - a p p e a r - to b e some o t h e r e x a m p l e s o f t h e i n c r e a s i n g n u m b e r o f r u t h e n i u m c o m p l e x e s w h i c h c o n t a i n a ( R u C l - R u ) b r i d g i n g u n i t 3 2 ' . 3 3 ' 8 3 ' 8 ' * ' 9 7 ' " ' 1 1 ? A n e x a m i n a t i o n 3*1 *1 o f t h e l i t e r a t u r e ( T a b l e IIT-r1l) s h o w s t h a t i n c a s e s w h e r e J ? { H} - n . m . d a t a o n s u c h c o m p o u n d s a r e a v a i l a b l e , o n e o f t h e A B p a t t e r n s h a s 3 1 1 2 r e l a t i v e l y c o n s t a n t P { H } . - n , m . r . . p a r a m e t e r s ( J p p = 36-38 H z , -48 p p m ) . T h i s h a s b e e n a s s i g n e d t o t h e r e s o n a n c e s o f t h e C l ^ R u t C l ) ( P P h ^ ) g m o i e t y a n d i s c o n f i r m a t i o n f o r t h e p r e s e n t a s s i g n m e n t W h i l e m o s t o f t h e c o m p o u n d s i d e n t i f i e d i n . T a b l e 1 1 1 - 1 1 c o n t a i n TT a c i d s ( L = C O , . G S , PF-•:).•, t h e c o m p l e x e s R u 0 C l ( L ) ( P P h J . ( L = d o n o r s o l v e n t ) 5 <• 4 J 4 may b e a m o r e g e n e r a l . c l a s s t h a n , h a s b e e n r e c o g n i z e d . C o l e - H a m i l t o n a n d W i l k i n s o n a p p e a r t o h a v e i s o l a t e d a n a c e t o -n i t r i l e c o m p l e x w h i c h i s d i r e c t l y a n a l o g o u s . to t h e p r o p o s e d DMA s t r u c t u r e ( I I I - - , L = C H ^ C N ) , T h e , c o m p l e x i s r e p o r t e d t o b e [ R u C l - C C H ^ C N ) ( P P h 3 ) 2 ] - o n t h e b a s i s o f e l e m e n t a l a n a l y s i s a n d P { H } -n . m . r . s p e c t r u m 1 1 • 1 and i s f o r m e d w h e n . R u C . l 2 ( C H 3 C N ) - ( P B . h 3 ) _ i s r e c r y s -t a l l i z e d f r o m t o l u e n e . One s e t o f r e s o n a n c e s o b s e r v e d f o r t h e d i m e r 2 ( J p p = 38 H z , 6^- = 4-9.7 ppm) i n d i c a t e s t h e p o s s i b i l i t y o f t h e C l ^ R u C l C P P h ^ . ) 2 m o i e t y . S i n c e t h e r e p o r t e d e l e m e n t a l a n a l y s i s ( F o u n d : C : 62 .4 ; H : 4-4; . N : . 1-..0.; Cl.:9,-7$). c o n t a i n s o n l y h a l f t h e n i t r o g e n e x p e c t e d f o r t h e r e p o r t e d c o m p l e x ( G a l e ' d : C : 61 .8 ; H : 4-4; N : 1.9; T A B L E 1 1 1 - 1 1 . P { H } - N . m . r . . s p e c t r a l p a r a m e t e r s f o r c o m p o u n d s c o n t a i n i n g t h e t r i - u - c h l o r o d i r u t h e n i u m ( l l ) f r a m e w o r k 3 " : ', L 2 j A B ' H z 2 J C D , H z P A B , ppm 6 A B , H z P C D , ppm 6 C D , H z S o l v e n t R e f e r e n c e D M A b 3 6 . 8 29.-9 4 5 . 7 231 4 6 .9 / 331 t o l - d g / D M A t h i s w o r k ( C I ' ) 3 6 . 0 - 4-8.1- - - - t o l - d g / D M A t h i s w o r k (c i " ) c 3 6 . 0 - 4 7 . 8 3 4 .4 - - t o l - d g / D M A t h i s w o r k a c e t o n e ^ 36.4 3 1 - 0 4 7 .4 1 7 9 44.9 2 5 0 a c e t o n e / C D C l ^ t h i s w o r k CH CN 3 8 . 0 2 7 . 0 4 9 . 7 1 8 6 4 6 , 5 101 C 6 D 6 111 CO 37 .5 2 4 . 6 4 8 . 0 9 7 . 7 4 0 . 3 7 4 . 2 C D C 1 C 6 D 6 1 0 8 CS 3 8 . 1 2^, • I\.. 48, . 8 124 .9 3 5 . 2 4 3 . 8 1 0 6 CS 37.4 24 .6 4 8 . 3 9 4 . 0 3 6 , 1 5 4 .9 C D C 1 3  C D 2 C 1 2 1 0 6 P F 3 6 .6 24.4 4 7 , 0 8 1 . 0 40 . 9 2 3 5 1 1 0 CO - 25.4 - - 40 , 8 6 4 . 0 C D C 1 3 C D C 1 3 C D C 1 3 C D C 1 3 C D 2 C 1 2 1 0 8 co e - 2 5 - 3 - - 3 9 .6 1 6 0 . 9 1 0 8 co e - 2 5 .5 - - 3 8 .6 1 5 5 . 7 1 0 8 C 0 f - 2 7 . 1 - - 40 . 8 1 1 3 . 3 1 0 8 C 0 g - 28. . 1 - - 4 1 . 8 8 5 1 1 0 L 2 jAB' H z 2 jCD' H z PAtr P p m 6AB' H z PCD' p p m 6^^, Hz Solvent Reference c o h 24.-4 - - 4-2.-6 138 C D 2 C 1 2 1 1 0 c o h 24.4 - - 41.0 158 C D 2 C 1 2 1 1 0 PF 3 26,5 - - 43.1 97.0 C D 2 C 1 2 1 1 0 a Where no values l i s t e d f o r AB parameters, the compound contains only one PPh_ per Ru -at t h i s end; P.-3 AB and 6 B r ), f o r example, r e f e r to midpoints and spacing between coupled resonances A and B; unless otherwise AB s p e c i f i e d , parameters r e f e r to spectra obtained at ambient temperatures. b Average values from Table I I I - 9. c. -70°C d) -20°C; referenced to PPh^ at -5.00 ppm. e For (Ph_P)-(Cl)Ru(ii-*Cl-) QRuCl.(CO)(PPh-) 3 2 3 3 f For (P.h 3P) 2(C0)Ru(y-Cl) 3Ru(C0) ( P P h ^ g For (Ph 3P ) ('Gl)• (CO)P.u(u-Cl) 3Ru(CO) ( P P h 3 ) 2 ' h For (Ph 3P) (PF ) (CI.) Ru( Rr CI) 3Ru (CO) (PPh 3) 2 - 9 7 -C l : 9 . 6 $ ) , t h e r e - f o r m u l a t i o n R u _ C l . ( C H . C N ) ( P P h J . ( r e q u i r e s C : 6 2 . 0 ; <• 4 3 5 4 H : 4.4; N : T . 0 ; C l : 9 . 9 $ ) a p p e a r s m o r e a c c e p t a b l e . S i m i l a r l y , G i l b e r t a n d W i l k i n s o n 1 1 Z / h a v e . : r e p o r t e d a s p a r i n g l y s o l u b l e c o m p l e x o f s t o i c h i o m e t r y R u C l ^ P P h ^ ) ^ . a c e t o n e w h i c h d e p o s i t s w h e n R u C l ^ P P h . ^ ) ^ i s r e f l u x e d i n a c e t o n e . I n m o r e d i l u t e s o l u t i o n a t r o o m t e m p e r a t u r e , t h e c o m p o u n d d i s s o l v e s a n d r e m a i n s i n s o l u t i o n 31 T h e c o m p l e x h a s b e e n c h a r a c t e r i z e d b y e l e m e n t a l a n a l y s i s a n d i n f r a r e d s p e c t r o s c o p y ( V p ^ ' ° ^ , = 1 6 6 0 cm ^ ) . R e p e a t i n g t h e s y n t h e s i s , we L/U, aceT ,one f i n d t h a t i t i s n e c e s s a r y t o u s e r i g o r o u s l y d r i e d a c e t o n e t o o b t a i n r u s t r e d c o m p o u n d s w h i c h e x h i b i t k e t o n i c s t r e t c h e s i n t h e i n f r a r e d s p e c t r a . When u n d r i e d - a c e t o n e i s u s e d , a g r e e n p o l y m e r f o r m s w h i c h c o n t a i n s n o a c e t o n e ( b y i . r . ) . H o w e v e r , t h e r e d s o l i d s c o n t a i n ' t w o b a n d s d u e t o a c e t o n e a t 1 7 0 5 a n d 1645 cm ' ( K B r ) . A l t h o u g h t h e i s o l a t e d s o l i d i s t o o i n s o l u b l e f o r n . m . r . s t u d i e s , i t h a s b e e n 31 1 p o s s i b l e t o o b t a i n a 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 b e f o r e p r e c i p i t a t i o n o c c u r s . T h e s p e c t r a l p a r a m e t e r s a r e g i v e n i n T a b l e 111-11 a n d i n d i c a t e a g a i n t h e R u „ C l . ( L ) ( P P h _ ) . s t r u c t u r e . T h e i s o l a t e d 2 4 i 4 c o m p o u n d i s s o r e - f o r m u l a t e d t o b e o f t h i s t y p e ( T I I - - , L = a c e t o n e ) . T h e i . r . s t r e t c h e s a t T645 a n d 1 7 0 5 cm a r e a s s i g n e d t o c o o r d i n a t e d a n d u n c o o r d i n a t e d a c e t o n e , r e s p e c t i v e l y . P a r s h a l l e t a l . 1 0 h a v e , r e p o r t e d : ; a - c o m p l e x - - - ' o f _ : the s a m e , g e n e r a l t y p e T IT- ; , w h e r e L = N ^ j - ' f r o m R u C l ^ P P h ^ ) ^ b y t h e n o v e l t e c h n i q u e o f 3*1 *1 r e v e r s e o s m o s i s . T h e P.{ H } - n „ m . r . s p e c t r a o f s a m p l e s o f [ R u C l ^ P P h ^ ) 2 J 2 u n d e r s h o w e d n o e v i d e n c e f o r a n y t r i p l y c h l o r o b r i d g e d s p e c i e s . • A p p a r e n t l y , t h e h i g h n i t r o g e n p r e s s u r e s u s e d b y P a r s h a l l ( 8 0 atm.) - a r e a t l e a s t , a s i m p o r t a n t a s t h e p h o s p h i n e d e f i c i e n c y i n t h e f o r m a t i o n o f t h e N 2 a d d u c t . 3*1 "1 T h e P { H } - n . m . r . p a r a m e t e r s o f R u „ C l r ( P P h „ ) , a r e a l s o i n 2 5 i 4 a c c o r d w i t h t h e ' g e n e r a l i z e d p a r a m e t e r s . T h e a p p a r e n t c h l o r o p h i l i c i t y o f r u t h e n i u m ( I I ) i s e v i d e n t i n t h e s t a b i l i t y o f t h i s R u 9 C l c . ( P P h „ ) ~ 2 5 j 4 s p e c i e s , a n d s u g g e s t e d a n a l t e r n a t e s y n t h e t i c r o u t e t o t h e d i m e r [ R u C l 2 ( P P h 3 ) 2 ] 2 . T h i s c o m p o u n d i s r e p o r t e d t o b e t h e p r o d u c t o f t h e h y d r o g e n a t i o n o f R u C l 3 ( P P h 3 ) 2 ' - 2 D M A i n D M A , a c c o r d i n g t o t h e r e a c t i o n : R u m c i 3 ( P P h 3 ) 2 ; . S , + iE2 • i [ R u C l 2 ( P P h 3 ) 2 J 2 + H C 1 (3.31) H o w e v e r , i t i s i m p o r t a n t t o n o t e t h a t t h e c h l o r o a n i o n i c d i m e r s p e c i e s , R u C l ( P P h ) , i s i n f a c t t h e p r o d u c t ( v i s i b l e s p e c t r u m ) . 2 D J 4 JJJ DMA • . . .. _ . . ... ... 2 R u c i 0 ( P P h J 0 . s + H 0 *- ( : iu-„c_ c (??h : ~') ;• •) ( D " A . : : " ) -y nci 3 i 2 <• 2 i > 3 4 (3.32) A s d e s c r i b e d b y W a n g a n d J a m e s 7 , t h e o v e r a l l i s o l a t e d y i e l d o f [ R u G l 2 ( P P ' h 3 ) 2 ] 2 f r o m R u C l 3 . . x H 2 0 i s o n l y _ca. 5 0 $ , m a i n l y b e c a u s e o f t h e l o w y i e l d i n t h e p r e p a r a t i o n o f R u C l 3 ( P P h 3 ) 2 ( D M A ) . D M A . B y c o n t r a s t , t h e b i s ( p h o s p h i n e ) a c e t o n e d e r i v a t i v e . ( 1 I I I , L =. a c e t o n e ) c a n b e p r e p a r e d i n e s s e n t i a l l y q u a n t i t a t i v e . y i e l d f r o m R u C l 3 < x H 2 0 . S t i r r i n g t h i s c o m p o u n d i n . D M A a t r o o m t e m p e r a t u r e w i t h a l l c h l o r i d e s o u r c e s t e s t e d (M = A s P h . , P P N , L i , N M e ) c a u s e d s l o w d i s s o l u t i o n a n d 4 f o r m a t i o n o f Ru 2 Cl,.(PPh-)^ . A t t e m p t s t o i s o l a t e t h e p e n t a c h l o r o d i m e . r ( [ I I j . , L = C l ) f r o m DMA u s i n g . b u l k y . c a t i o n s w e r e u n s u c c e s s f u l . W o r k u p w i t h m e t h a n o l - g a v e i n a l l c a s e s t h e f i v e c o o r d i n a t e d i m e r , [ R u c i 2 ( p p h 3 ) 2 ] 2 -;(r): - C l ~ Ru-ClK(PPh,) : *~ Ru-Cl.(PPh,), + (3.33) 2 5 3 4 MeOH 2 4 3 4 - 9 9 -D i s s o l u t i o n d i d n o t o c c u r i n t h e a b s e n c e o f c h l o r i d e i o n s u g g e s t i n g t h a t DMA i s t o o w e a k a l i g a n d t o d i s p l a c e t h e a c e t o n e . U s i n g e l e v a t e d t e m p e r a t u r e s ( - 8 0 ° C ) i n t h e a b s e n c e o f c h l o r i d e c a u s e d s o l v e n t d e c o m p o s i t i o n , a s t h e i s o l a t e d s o l i d s .showed. , c a r - b o n y l - e o n t a i n i n g i m p u r i t i e s . A t t e m p t s t o c l e a v e t h e p o l y m e r f o r m e d w h e n R u C ^ C P P h ^ ) ^ i s r e f l u x e d i n w e t a c e t o n e w e r e u n s u c c e s s f u l ; i t . s h o w e d n o t e n d e n c y t o d i s s o l v e i n c h l o r i d e s o l u t i o n s o f DMA e v e n a f t e r o n e w e e k . T h e w e a k n e s s o f t h e i n t e r a c t i o n b e t w e e n DMA a n d t h e 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 [ R u C l ^ P P h ^ ) ^ ] 2 i s u n e x p e c t e d . T a b l e 1 1 1 - 1 2 l i s t s s e l e c t e d b a s e p a r a m e t e r s f o r s e v e r a l s o l v e n t s . T A B L E 1 1 1 - 1 2 . S e l e c t e d b a s e p a r a m e t e r s . P a r a m e t e r & V a l u e s f o r : DMA a c e t o n e C H ? C N p y r i d i n e D o n o r n u m b e r 2 7 . 3 1 7 . 0 1 4 . 1 3 3 . 1 A c c e p t o r n u m b e r 1 3 . 6 1 2 . 5 1 9 . 3 U . 2 2 . 5 8 2 . 3 3 1 . 3 4 6.4 1 . 3 2 0 . 9 9 0 . 8 9 1 . 2 1 . 2 6 2 . 3 6 1 .51 5 . 4 7 a V a l u e s t a k e n f r o m J . E . H u h e e y , " I n o r g a n i c C h e m i s t r y " , 2 n d e d i t i o n , H a r p e r a n d R o w , N e w Y o r k . , 1 9 7 8 ; T a b l e s 7 . 4 B a n d 8.4. b S e e a l s o R . S . D r a g o a n d B . B . W a y l a n d , J . A m . C h e m . S o c , 8 7 , 3571 ( 1 9 6 5 ) . - 1 0 0 -T h e s o l v e n t s l i s t e d a r e k n o w n t o e x h i b i t d i f f e r e n t r e a c t i v i t i e s t o w a r d R u C ^ C P P h ^ ) ^ . A c e t o n i t r i l e , a n d n i t r i l e s i n g e n e r a l , r e a c t t o f o r m s i x - c o o r d i n a t e m o n o m e r s , R u C l 2 ( C H C N ) 2 ( P P h 3 ) 2 " " 2 ' , : . 7 w h e r e a s p y r i d i n e c a n r e p l a c e a l l t h r e e t r i p h e n y l p h o s p h i n e s t o f o r m R u C l 0 ( p y r i d i n e 1 • U s i n g <• 4 e i t h e r G u t m a n n ' s d o n o r - a c c e p t o r o r D r a g o ' s C g / E g m o d e l , t h e h i g h r e a c t i v i t y o f p y r i d i n e i s e a s i l y u n d e r s t o o d . H o w e v e r , w h i l e G u t m a n n ' s m o d e l i s p e r h a p s a m b i g u o u s , s i n c e t h e c o r r e s p o n d i n g a c i d p a r a m e t e r s o f r u t h e n i u m ( l l ) a r e n o t k n o w n , D r a g o ' s m o d e l p r e d i c t s t h a t b o t h DMA a n d a c e t o n e w o u l d c o o r d i n a t e m o r e s t r o n g l y t h a n C H ^ C N . C o n t r i b u t i o n s o f s t e r i c e f f e c t s may i n p a r t b e r e s p o n s i b l e f o r t h i s p o o r e r b i n d i n g t h a n p r e d i c t e d . A l t e r n a t i v e l y , t h e E g a n d C g v a l u e s may s i m p l y n o t r e f l e c t t h e p r e f e r r e d c o o r d i n a t i o n o f n i t r o g e n - d o n o r l i g a n d s t o r u t h e n i u m ( I I ) . . T h e p a r t i c u l a r s t a b i l i t y o f t h e t r i p l e h a l i d e b r i d g e d a r r a n g e m e n t may a l s o b e i n p a r t r e s p o n s i b l e f o r t h i s . I t s h o u l d b e v e r y i n t e r e s t i n g , t h e n , t o c o m p a r e t h e s o l u t i o n c h e m i s t r y o f t h e b r o m o a n a l o g u e R u B r ^ P P h ^ ^ i n D M A , a s t h e t r i p l y - b r o m o - b r i d g e d a r r a n g e m e n t 31 1 i s y e t u n k n o w 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 s t u d y a n d P { H } - n . m . r . w o r k w e r e a m b i g u o u s i n d e f i n i n g 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 ) p r o d u c t i n t h i s , s y s t e m . I t may b e p o s s i b l e t o " c o u p l e " a b r o m i d e i o n r e a c t i o n w i t h t h e p h o s p h i n e d i s s o c i a t i o n r e a c t i o n , a n a l o g o u s t o t h e c h l o r i d e w o r k p r e s e n t e d h e r e , f o r a n a c c u r a t e d e f i n i t i o n t o b e m a d e . F i n a l l y , b e c a u s e o f t h e p a r t i c i p a t i o n o f DMA i n t h e e q u i l i b r i a i n v o l v i n g R u C l ^ P P h ^ ) y i t i s n e c e s s a r y t o i n c o r p o r a t e i t s c o n c e n t r a t i o n i n t o t h e v a l u e s f o r K , a n d K , : 4 o K j , 2 R u C l 2 ( P P h 3 ) 3 + DMA „ R u 2 C l ^ ( P P h 3 ) ^ ( D M A ) + 2PPh 3 (3.34) KJ , R u „ C l , ( P P h _ ) . ( D M A ) + C I " - R u „ C l c ( P P h 0 ) " + DMA ( 3 . 3 5 ) o 2 4 3 4 2 5 3 4 -101-g i v i n g c o r r e s p o n d i n g c o r r e c t e d c o n s t a n t s o f K | = (1.4 ± 0 . 5 ) x 10"3, a n d K £ = ( 2 . 8 ± 0 . 5 ) x 1 0 5 . T h e o v e r a l l e q u i l i b r i u m : 2 R u C l 2 ( P P h 3 ) 3 + 0 1 " „ R u 2 C l 5 ( P P h 3 ) ^ " + 2 P P h 3 ( 3 . 9 ) i s u n a f f e c t e d b y t h i s s o l v a t i o n . A l t h o u g h t h e r e a p p e a r s a l s o t o b e c o n s i d e r a b l e s o l v e n t i n t e r a c t i o n w i t h R u B r 2 ( P P h 3 ) 3 i n D M A , i t s n a t u r e h a s n o t b e e n d e t e r m i n e d , a n d t h e c o r r e s p o n d i n g c o r r e c t i o n s a r e n o t m a d e . - 1 0 2 -G H A P T E R 4 . C H A R A C T E R I Z A T I O N AND R E A C T I V I T Y OF 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 A R Y L P H O S P H I N E ^ D I - R H T H E N I U M ( I - I l );.-• , 4 . 1 I n t r o d u c t i o n . W a n g 7 & ' 1 2 r e p o r t e d t h a t c o m p l e x e s o f t h e g e n e r a l t y p e R u X ^ L ^ ( X = C l , B r ; L = P P h ^ , A s P h ^ ) r e a c t w i t h m o l e c u l a r h y d r o g e n i n DMA t o I I I I I I I p r o d u c e H R u ^2^2' ^ U ^2^2' 0 r ^ u ^2 s u c c e s s i v e s t e p s d e p e n d i n g o n t h e n a t u r e o f X a n d L, t h e p r e s e n c e o f a d d e d b a s e , a n d t e m p e r a t u r e . O f p a r t i c u l a r i n t e r e s t t o t h e p r e s e n t w o r k was t h e r e p o r t e d r e a c t i o n o f R u C l 3 ( P P h 3) 2.2DMA w i t h H 2 t o g i v e e i t h e r [ R u C l g C P P h ^ ) 2 ] 2 o r [ H R u C l ( P P h 3 ) 2 ] 2 , d e p e n d i n g o n c o n d i t i o n s : DMA R u C l 3 ( P P h 3 ) 2 + _ H 2 - i [ R u C 1 2 ( p p h 3 ) 2 ] 2 + DMA.HC1 (<'4.1) D M A , o r R u C l ( P P h ) 2 + 2P .S . + 1 § H 2 . - _ [ H R u C l ( P P h _ ) 2 ] 2 t o l u e n e + 2P.S.HC1 (4.2) B o t h p r o d u c t s h a v e b e e n i s o l a t e d a n d c h a r a c t e r i z e d p r e v i o u s l y , a l t h o u g h i t s h o u l d b e n o t e d t h a t t h e p r o d u c t o f e q u a t i o n A . I b e f o r e w o r k u p i s t h e p e n t a c h l o r o a n i o n i c d i m e r a s i d e n t i f i e d b y v i s i b l e s p e c t r o s c o p y ( C h a p t e r 3): - 1 0 3 -DMA 2 R u C l 3 ( P P h 3 ) 2 + H 2 - [DMAH] [ R u 2 C l 5 ( P P h 3 ) ^ ] + D M A . H C 1 ( 4 . 3 ) W a n g f o u n d n o c o n t r i b u t i o n s o f a f u r t h e r r e a c t i o n w i t h 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 b a s e , a n d t h i s a p p e a r e d t o b e d u e t o t h e e x t r e m e s e n s i t i v i t y o f t h e p r o d u c t h y d r i d e t o t h e r e l e a s e d a c i d : [ D M A H ] [ R u 2 C l 5 ( P P h 3 ) J + 2 H 2 „ — = = - [ H R u C l ( P P h 3 ) 2 J 2 + 2 D M A . H C 1 ( 4 . 4 ) B y a d d i n g t h e s t r o n g n o n - c o o r d i n a t i n g b a s 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 ( t r i v a l l y ' • „ c a l l e d P r o t o n S p o n g e ® , P . S . ) t o r e m o v e t h e a c i d , t h e r e a c t i o n w a s f o u n d t o p r o c e e d f u r t h e r t o f o r m a h y d r i d e c o m p l e x . T h i s w a s 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 J 2 i n t h e p a r t i c u l a r c a s e 7 a ' 1 , 2 a l t h o u g h a w i d e r r a n g e o f [ H R u X L 2 ] 2 c o m p l e x e s w a s s i m i l a r l y p r e p a r e d . C h a r a c t e r i z a t i o n h a s s i n c e b e e n e x p a n d e d - b y m e t h o d s i n c l u d i n g g a s u p t a k e s ( 1 . 5 H 2 p e r r u t h e n i u m ( i l l ) p r e c u r s o r ) , e l e m e n t a l a n a l y s e s , 1 31 1 i n f r a r e d , H - a n d P{ H } - n . m . r . s p e c t r o s c o p y , a p r e l i m i n a r y c r y s t a l l o -g r a p h i c s t u d y , a n d c h e m i c a l , r e a c t i o n s ( w i t h C O , P P h 3 > a n d H C l ) . A m o l e c u l a r w e i g h t d e t e r m i n a t i o n o f t h e DMA s o l v a t e ? a , [ H R u C l ( P P h 3 ) 2 a DMA] g a v e a n e f f e c t i v e v a l u e o f 500 i n b e n z e n e a n d w a s i n t e r p r e t e d I n t e r m s o f t h e d i s s o c i a t i o n g i v e n i n '4.5:-' • [ H R u C l ( P P h 3 ) 2 . D M A ] 2 m- [ H R u C l ( P P h 3 ) ^ + 2DMA (4.5) M o r e c o n v i n c i n g e v i d e n c e f o r t h e d i m e r i c n a t u r e i n t o l u e n e came f r o m 3 1 P { 1 H } - n . m . r . d a t a a n d a p r e l i m i n a r y c r y s t a l l o g r a p h i c s t u d y o n - 1 0 4 -t h e P t o l ^ d e r i v a t i v e . T h e X - r a y s t r u c t u r e s h o w e d a n a s y m m e t r i c c h l o r o - b r i d g e d d i m e r w i t h a d i s t o r t e d s q u a r e p y r a m i d a l s t r u c t u r e a b o u t 3 *l 1 e a c h r u t h e n i u m c e n t e r 1 1 . 3 T h e J P{ H} - n . m . r . s p e c t r a " - i n : ' t o l u e n e ( + 50 C t o - 7 0 ° C ) s h o w e d a f l u x i o n a l m o l e c u l e , b u t 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 c o u l d n o t b e o b t a i n e d ; a t - 7 0 ° G t h e s p e c t r u m s h o w e d 3 u n r e s o l v e d r e s o n a n c e s a t 78 ( P A ) , 6 1 . 3 ( P g , P g ) , a n d 2 9 . 0 (P ) ppm o f r e l a t i v e i n t e n s i t y 1 : 2 : 1 t h a t w e r e i n t e r p r e t e d i n t e r m s o f t w o u n r e s o l v e d A B q u a r t e t s a n d r a t i o n a l i z e d b y a n e q u i l i b r i u m b e t w e e n e q u i m o l a r a m o u n t s o f I , a n d I I : •' CI.) ( I I ) 1 T h e H - n . m . r . s p e c t r a o v e r t h e same t e m p e r a t u r e r a n g e c o u l d n o t b e r e s o l v e d , s h o w i n g o n l y b r o a d h y d r i d e , r e s o n a n c e s a t e v e r y t e m p e r a t u r e . I n c o n t r a s 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 d e f i n e d i n i t i a l l y 7a a s a s o l v a t e d m o n o m e r , b a s e d m a i n l y o n o l e f i n b i n d i n g s t u d i e s . T h i s i n t e r p r e t a t i o n w a s l a t e r c h a l l e n g e d b y d e v i a t i o n s i n t h e B e e r ' s - L - 3 L a w p l o t 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 2 . 4 x 1 0 M t o 7 x 1 0 M , a n d r e - e v a l u a t e d t o i n c o r p o r a t e a m o n o m e r - d i m e r e q u i l i b r i u m : [ H R u C l ( P P h 3 ) 2 ] 2 „ 2 H R u C l ( P P h 3 ) 2 (4.6) Two o l e f i n h y d r o g e n a t i o n s t u d i e s u s i n g M H R u C l . ( P P h „ ) p " w e r e d o n e - 1 0 5 -i n D M A , e a c h s u g g e s t i n g a d i f f e r e n t m e c h a n i s m . T h e h y d r o g e n a t i o n o f a c r y l a m i d e s h o w e d a s e c o n d - o r d e r d e p e n d e n c e o n [ R u ] ^ , a n i n v e r s e d e p e n d e n c e o n a c r y l a m i d e a n d o n a d d e d p r o p i o n a m i d e , a n d a f i r s t - t o z e r o - o r d e r d e p e n d e n c e o n h y d r o g e n . T h e s e d a t a w e r e e x p l a i n e d b y t h e f o l l o w i n g m e c h a n i s m : K H R u C l ( P P h 3 ) 2 + H 2 C = C H C 0 N H 2 . . R u C l ( P P h - ) 2 ( C H - C - N H _ ) ( 4 . 7 ) H - C 0 R u C l ( P P h 3 ) 2 ( C H - C - N H 2 ) + H R u C l ( P P h 3 ) 2 , , ' » [ R u C K P P h - ) - ] - , + H ^ G 0 k - 1 , , 3 GH-CH-gNH- ( 4 . 8 ) 0 k [ R u C l ( P P h 3 ) 2 ] 2 + H 2 2 H R u C l ( P P h 3 ) 2 ( 4 - 9 ) w h e r e K i s t h e e q u i l i b r i u m c o n s t a n t f o r a l k y l f o r m a t i o n , a n d k ^ , k , a n d k 2 a r e i n d i v i d u a l r a t e c o n s t a n t s . O f p a r t i c u l a r i n t e r e s t w a s t h e i m p l i e d e x i s t e n c e o f a r u t h e n i u m ( l ) s p e c i e s , [ R u C l ( P P h 3 ) 2 ] 2 > c a p a b l e o f a c t i v a t i n g t h e C - H b o n d i n p r o p i o n a m i d e ( t h e k ^ s t e p ) . T h e h y d r o g e n a t i o n o f h e x - 1 - e n e s h o w e d a n e a r f i r s t - o r d e r d e p e n d e n c e o n [ R u ] _ , a f i r s t - t o z e r o - o r d e r , d e p e n d e n c e o n h e x - 1 - e n e , p r e d o m i n a n t l y f i r s t - o r d e r d e p e n d e n c e o n h y d r o g e n a t h i g h s u b s t r a t e c o n c e n t r a t i o n s , a n d a f i r s t - t o z e r o - o r d e r d e p e n d e n c e o n h y d r o g e n a t l o w e r s u b s t r a t e c o n c e n t r a t i o n 8 - T h e k i n e t i c d e p e n d e n c e s w e r e i n t e r p r e t e d i n t e r m s o f t h e m o r e " u s u a l " 1 m e c h a n i s m ( 4 . 1 0 - 4 - 1 1 ) : K 1 H R u C l ( P P h - ) - + o l e f i n _ R u C l ( a l k y l ) ( P P h ) ( 4 . 1 0 ) k _ 1 J k 2 R u C l ( a l k y l ) ( P P h 3 ) 2 + H 2 ~ - H R u C l ( P P h - ) - + a l k a n e (4_ .11) - 1 0 6 -T h e m e c h a n i s m f o r t h e h y d r o g e n a t i o n o f h e x - 1 - e n e ( o r a c r y l a m i d e ) u s 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 H R u C l ( P P h 3 ) 3 a s t h e c a t a l y s t w a s s i m i l a r t o t h a t o f e q u a t i o n s 4>1 0 a n d 4..11 i n t h a t b o t h i n v o l v e d a r a t e d e t e r m i n i n g r e a c t i o n o f a r u t h e n i u m a l k y l w i t h m o l e c u l a r h y d r o g e n 6 0 . A l t h o u g h a d d i t i o n o f P P h ^ i n h i b i t e d t h e o v e r a l l r a t e o f h y d r o g e n a t i o n o f h e x - 1 - e n e b y t h e b i s p h o s p h i n e s p e c i e s , c o n s i s t e n t w i t h c o m p e t i t i v e f o r m a t i o n o f H R u C l ( P P h 3 ) y t h e r a t e o f t h e h y d r o g e n a t i o n o f t h e p r o p o s e d a l k y l s p e c i e s w a s a p p r o x i m a t e l y e i g h t t i m e s f a s t e r f o r t h e t r i s ( p h o s p h i n e ) c o m p l e x . T h i s w a s c o n s i d e r e d a s s u p p o r t f o r t h e r e c e n t l y p r o p o s e d m e c h a n i s m f o r t h e h y d r o g e n a t i o n s u s i n g H R u C l ( P P h 3 ) y i n w h i c h t h e r a t e d e t e r m i n i n g s t e p w a s r e a c t i o n o f w i t h R u C l ( a l k y l ) ( P P h ^ ) ^ a n d n o t R u C l ( a l k y l ) ( P P h ^ g , a s o r i g i n a l l y p o s t u l a t e d . 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 t h e b i s t p h o s p h i n e ) h y d r i d e a n d P P h ^ w e r e s t u d i e d b y s t o p p e d f l o w m e t h o d s 8 , a n d w e r e i n t e r p r e t e d i n t e r m s o f t h e f o l l o w i n g m e c h a n i s m : k 1 [ H R u C l ( P P h 3 ) 2 ] 2 , 2 H R u C l ( P P h 3 ) 2 (4. 1 2 ) k - 1 k 2 H R u C l ( P P h J 0 + P P h ~ »• H R u C l ( P P h J 0 (4. 1 3 ) 3 <s 3 3 3 B e c a u s e r e a c t i o n 4.14 s e e m e d t o h o l d g o o d . p r o m i s e a s a p r o b e i n t o 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 h y d r o g e n a t i o n o f t h e r u t h e n i u m ( l l ) d i m e r s g e n e r a t e d f r o m R u C l 2 ( P P h 3 ) y t h i s c h e m i s t r y h a s b e e n i n v e s t i g a t e d . R u 2 C l ^ ( L ) ( P P h 3 ) ^ + 2 H 2 — [ H R u C l ( P P h 3 ) 2 ] 2 + 2 H C 1 + L L = C I " , D M A . ' U . 1 4 ) B a s e d o n t h e p r e s e n t w o r k , i t w i l l b e s h o w n t h a t t h e h y d r i d e p r o d u c t s - 1 0 7 -h a v e b e e n m i s f o r m u l a t e d , a n d s h o u l d b e r e g a r d e d a s [ H ^ R u X L ^ ] ^ ( X = C l , B r : L = P P h ^ , P t o l - , A s P h - ) . R e s u l t s o f t h e i n v e s t i g a t i o n o f t h e p a t h w a y o f r e a c t i o n 4.14 ( c o r r e c t e d t o g i v e t h e [ H g R u C ^ P P h ^ ) p r o d u c t ) a r e p r e s e n t e d s e p a r a t e l y ( C h a p t e r 5)• 4 . 2 D a t a . 4 . 2 . 1 - . - P r e c u r s o r s f o r u p t a k e e x p e r i m e n t s . T h e p r e c u r s o r s u s e d i n t h e s e e x p e r i m e n t s w e r e f o r t h e m o s t p a r t k n o w n , a n d t h e i r p r e p a r a t i o n s a r e g i v e n i n C h a p t e r 2 . We f o u n d e x t r e m e d i f f i c u l t y i n p r e p a r i n g t h e b r o m o a n a l o g u e s , p a r t i c u l a r l y R u B r - ( M e O H ) ( P P h ^ ) -•• O t h e r w o r k e r s 1 1 * * » 1 1 ; 5 > 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 - *• 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°C (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)„ 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 ° C . C o m p o u n d *1 § 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 • *~ 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): » R u X 2 L 2 ' + l i H 2 • i [ H 2 R u X L 2 ] 2 + HX (4.17) R u X 3 L 2 + i H 2 »- ' 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 •" 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 • 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) • 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» (30.2) DMA 104 3.9 2.00 E» (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 • 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 °C , 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 ) • (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 „ ( P P h J „ ; 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 ° 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 ° 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 ° 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 • 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 • [ H 2 R u C l ( P P h - ) 2 } 2 « ' 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 ) • (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 „ - 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 ° 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 -• ( • • • • • 1 1 1 • 111 • • i • 1 1 1 1 • • • • 11 • • 11 11 • • • • 1 1 1 1 1 1 • • • 11 "• • i • i • • 111 • • • • 11 HI • i 1.98 1.88 200 4 4 gauss . . r— K 2.17 ' • • ' • I l l • • — • • • • + 2.27 • i • 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 — 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 ° 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 ) « A t 8 0 ° C - . i n t o l u e n e - d c , t h e ~ h y _ r ± 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 ° 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 ° C t o - 7 0 ° 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 ° 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 ° G . F u r t h e r c o o l i n g t o - 9 5 ° 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 ° C ; v x = 30 H z ) . o s - 1 3 . 2 8 6 ( 0 D o C l „ ; = 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 ° 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 ° 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 ° 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 ° 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 ° 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°C 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 ° 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 ° 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 • 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°C 60.4 2 7 . 9 80°C ^ ^ ^ ^ 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°C 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„RuCl(Ptol0)J. in 2 3 2 J 2 slow exchange using couplings shown in the inset.. of DMA«,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 : : | | • • • • ' • 1 • • • 1 1 ] . . 1 • i • 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 ° 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