Copper(II)-promoted solvolyses of nickel(II) complexes. II. Tridentate and tetradentate Schiff base ligands containing remote substituents

Abstract

The kinetics of copper(II)-promoted solvolyses of two series of nickel(II) complexes containing polydentate Schiff bases with various remote substituents, in dimethyl sulphoxide (dmso), are discussed from the viewpoints of rate constants and of enthalpies and entropies of activation. Appearance of an isokinetic relation for the tridentate (ONS donors) reactants may indicate a common mechanism operative within this reactant series. Rate constants appear related to σ_p values in such a way that a dissociative mechanism appears important for the tridentate reactants, while characterization in terms of associative behaviour is indicated for the tetradentates.