Theoretical Studies of Oxidative Addition and Reductive Elimination : H 2 + Pt ( PH , ) , - Pt ( H ) , ( PH &
نویسندگان
چکیده
Ab initio calculations (Hartree-Fock, generalized valence bond, and configuration interaction), utilizing relativistic core potentials, have been used to follow the oxidative addition of Hz to Pt(PH,),. We find an activation barrier of 2.3 kcal/mol and an exothermicity of 15.9 kcal/mol. From examination of the geometries and wave functions, we find that up to the transition state the H-H bond is still intact. The role of the Pt s'd9 and dIo states in oxidative addition is described, and the effects of including electronic correlation are discussed. The implications for reductive elimination of the dimethyl and hydridomethyl complexes are also discussed.
منابع مشابه
Reductive Coupling of H - H , H - C , and C - C Bonds from Pd Complexes
Reductive coupling to form H-H, C-H, and C-C bonds from transition-metal complexes is of fundamental importance in many catalytic processes. However, despite numerous experimental' and theoretical2 studies, there remain a number of puzzles concerning these processes. For example, reductive elimination of methane from Pt(H)(CH3)(PPh3), is quite facile at -25 'C,ld while Pt(CH3)2(PPh,)2 is qkite ...
متن کاملRedox activation of alkene ligands in platinum complexes with non-innocent ligands.
The reactivity of metal olefin complexes with non-innocent ligands (NILs) was examined. Treatment of PtCl(2)(diene) with the deprotonated catechol or aminophenol ligands afforded the corresponding Pt(NIL)(diene) complexes. The Pt((t)BA(F)Ph)(COD), Pt((t)BA(F)Ph)(nbd), and Pt(O(2)C(6)H(2)(t)Bu(2))(COD) (H(2)(t)BA(F)Ph = 2-(2-trifluoromethyl)anilino-4,6-di-tert-butylphenol, H(2)O(2)C(6)H(2)(t)Bu(...
متن کاملPlatinum-oxygen Bond Formation: Kinetic and Mechanistic Studies
Reaction of [PtMe(C^N)(SMe2)] (C^N = 2-phenylpyridinate (ppy); 1a, C^N = benzo[h]quinolate, (bhq); 1b) with hydrogen peroxide gives the platinum(IV) complexes trans-[PtMe(OH)2(C^N)(H2O)] (C^N = ppy; 3a, C^N = bhq, 3b) bearing platinum-oxygen bonds. The Pt(II) complexes 1a and 1b have 5dπ(Pt)→π*(C^N) MLCT band in the visible region which is used to easily follow the kinetic of its reaction with ...
متن کاملUntersuchungen zur reduktiven Eliminierung des Biphenyl-Systems aus substituierten cis-Bis(phenyI)bis(triphenylphosphan)platin(II)-Verbindungen On the Reductive Elimination of the Biphenyl System from Substituted ci6-Bis(phenyl)bis(triphenylphosphane)platinum(II) Compounds
Platinum-organic Compounds, Syntheses, Reductive Elimination, Activation Parameters The Compounds cw-[Pt(PPh3)2(4-X-C6H4)2] [X = F, Cl, CF3, OCH3, N(CH3)2] and cis[Pt(PPh3)2(4-X-C6H4)(Y-C6H4)] [X = F/Y = 3 Cl, 4-C1, 3-CH30, 4 -CH 3 0; X = CF3/Y = 3-F, 4-F] have been synthesized and studied thermally with respect to the reductive elimination of disubstituted biphenyls. Activation parameters A H+...
متن کاملMultinuclear Variable Temperature NMR Studies on Cyanide, Water and Hydroxyl Group Scrambling on Halogenation of K2[Pt(CN)4] and Related Reactions
195Pt and 1H NMR has been used to show that addition of chlorine and bromine to [Pt(CN)4]2_ in presence of perchloric acid in water results in cyanide and water scrambling with formation of eleven complexes of the type [Pt(CN)4-nCl(H2O)n+1](n-1)+ (n=0, 1, 2, 3, 4). Addition of NBu4OH ...
متن کامل