Part I. Carbanion stabilization by adjacent sulfur: Polarizability, resonance, or negative hyperconjugation? Experimental distinction based on intrinsic rate constants from (phenylthio)nitromethane and 1-nitro-2-phenylethane. Part II. Mechanistic studies of hydrolysis and nucleophilic substitution of transition metal carbene complexes.

摘要

art I. A kinetic study of proton transfer from PhSCH;Part II. A kinetic study in 50% acetonitrile-50% water (v/v) at 25;The hydrolysis reaction occurs in two stages; the first is the formation of (CO);Alkanethiolate ion nucleophilic substitution reactions were found to occur via a two step process, and either step could be monitored depending on the pH of the solution. The rate constants for the nucleophilic attachment step (k;Other noteworthy observations are: (1) a change in the metal (Cr vs W) had no significant effect on the rate constant for attachment to the carbene carbon; and (2) substitution of methoxy by an ethoxy group lowers the reactivity. The lower reactivity for the ethoxy derivative can be attributed to a more effective reactant state stabilization by stronger