Kinetics and thermodynamics of fast square-planar–octahedral inter-conversion. Part 1. The reaction of [biacetyl bis-α-hydroxybenzylidene-hydrazone(2–)-N1N1′OO′]nickel(II) with some pyridines in chlorobenzene

Abstract

A kinetic study has been made of the equilibrium (i)[bbh = biacetyl bis-α-hydroxybenzylidenehydrazone(2–)-N¹N¹′OO′ L = pyridine, 3-methylpyridine, and 4-methylpyridine] in chlorobenzene by using a microwave temperature-jump apparatus. [graphic omitted] + 2L ⇌ [graphic omitted] (i) The experimental results are consistent with the mechanism in (ii) and (iii) where (ii) is the rate-determining step. [Ni(bbh)L₂] [graphic omitted] [Ni(bbh)L]+ L (ii), [Ni(bbh)L]⇌[Ni(bbh)]+ L (iii) Activation Parameters associated with the rate constant k₁, are in agreement with the dissociative nature of the reaction.