The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.32993-05-8, Name is Chlorocyclopentadienylbis(triphenylphosphine)ruthenium(II), molecular formula is C41H35ClP2Ru. In a Article£¬once mentioned of 32993-05-8, Recommanded Product: Chlorocyclopentadienylbis(triphenylphosphine)ruthenium(II)
Phosphine substitution in indenyl- and cyclopentadienylruthenium complexes. Effect of the eta5 ligand in a dissociative pathway
The indenyl complex [RuCl(eta5-C9H7)(PPh3) 2] (1) reacts with monodentate (L: PMePh2, PMe2Ph, PMe3) or bidentate [L-L: Ph2PCH2PPh2 (dppm), Ph2P(CH2)2PPh2 (dppe)] phosphines to give monosubstituted [RuCl(eta5-C9H7)(PPh3)(L)], bisubstituted [RuCl(eta5-C9H7)(L)2], or chelated complexes [RuCl(eta5-C9H7)(L-L)] in toluene or tetrahydrofuran. The corresponding cyclopentadienyl complex [RuCl(eta5-C5H5)(PPh3) 2] (2) reacts similarly, at higher temperatures or longer reaction times. In refluxing toluene, PMe3 and dppm give ionic products [Ru(eta5-C9H7)(L)3]Cl. The kinetics of PPh3 substitution by PMePh2 and PMe2Ph in tetrahydrofuran yield first-order rate constants that are independent of the concentration or the nature of phosphine. Rate decrease in the presence of added PPh3 or saturation behavior at high [PPh3] indicates that the reaction proceeds by a dissociative mechanism, in which extrusion of PPh3 is rate determining. Kinetics for the reaction with PMePh2 in the temperature range 12-40C for the indenyl and 20-50C for the cyclopentadienyl complex give the following activation parameters: DeltaH? = 26 ¡À 1 kcal mol-1 and DeltaS? = 11 ¡À 2 cal mol-1 K-1 for 1 and DeltaH? = 29 ¡À 1 kcal mol-1 and DeltaS? = 17 ¡À 2 cal mol-1 K-1 for 2. Complex 1 is 1 order of magnitude more reactive than 2, indicating more efficient stabilization of 16-electron intermediates RuCl(eta5-ligand)(PPh3) by the indenyl group. Cyclic voltammetry measurements for [RuCl(eta5-ligand)(L)2] in dichloromethane indicate that indenyl or pentamethylcyclopentadienyl complexes are oxidized at lower potentials than cyclopentadienyl complexes. Kinetics and electrochemistry suggest that indenyl is electron donating toward the metal fragment, with respect to cyclopentadienyl.
Note that a catalyst decreases the activation energy for both the forward and the reverse reactions and hence accelerates both the forward and the reverse reactions.Recommanded Product: Chlorocyclopentadienylbis(triphenylphosphine)ruthenium(II), you can also check out more blogs about32993-05-8
Reference£º
Highly efficient and robust molecular ruthenium catalysts for water oxidation,
Catalysts | Special Issue : Ruthenium Catalysts – MDPI