Related Experiment Video
Updated: Sep 27, 2026

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Electronic effects on the rates of coupled two-electron/halide self-exchange reactions of substituted ruthenocenes
1Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459, USA.
Abstract:
The complexes (MemCp)(MenCp)Ru (m,n = 1,1; 0.4; 0.5; 1.5) have been synthesized along with the corresponding halometalloceniums [(MemCp)(MenCp)RuX]+ (X = Cl, Br, I). The two-electron/halide transfer self-exchange kinetics have been determined and compared to those of the Cp2Ru/[Cp2RuX]+ parent system. Methylation decreases the rate of exchange monotonically, and plots of ln(kex) vs number of methyl groups are linear for constant X. It is concluded that steric effects do not contribute significantly to the observed kinetics. Thermodynamic studies of halide substitution equilibria support the conclusion that the electronic effects of methylation are essentially additive.
Related Concept Videos
E1 Reaction: Kinetics and Mechanism
SN2 Reaction: Kinetics
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a reaction.
E2 Reaction: Kinetics and Mechanism
SN2 Reaction: Transition State
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
Predicting Products: Substitution vs. Elimination
The following factors can influence the mechanisms competing against each other:
Nucleophilic Aromatic Substitution: Elimination–Addition

