Copper(II)-promoted solvolyses of nickel(II) complexes. III. Tetradentate Schiff base ligands containing various diamine segments

Abstract

The large variations in the rates of the copper(II)-promoted solvolyses of various nickel(II) complexes, containing Schiff base ligands with varying diamine substituents, is attributed to steric effects. The important rate differences occur for reactants whose stereochemistries and electronic properties appear little different. However, the steric effects cannot be viewed definitely from either nickel-diamine dissociation or copper-diamine formation. Nickel reactants which may be distorted from planarity give trimeric products on reaction with copper in dmso and dmf, if the reactions are carried out at high initial concentration ratios of copper(II) to nickel complex. Ligand substitution studies indicate a differing reactivity sequence for the diamine-substituted ligands in their capacities as entering, compared to leaving, groups.