Chemistry of polydentate ligands. Part 1. Condensation reactions of aldehydes and ketones with 6,6′-dihydrazino-2,2′-bipyridylnickel(II) perchlorate

Abstract

The complex 6,6′-dihydrazino-2,2′-bipyridylnickel(II) perchlorate has been prepared and its reactivity as a macrocyclic precursor investigated. This complex does not undergo cyclisation on reaction with acetone and other α-methyl ketones, or aldehydes, but preferentially forms a series of stable bis(hydrazone) complexes. The metal-free ligands have been isolated and manifest imino–azo tautomerism. This tautomerism has been studied by n.m.r. spectroscopy and evidence is presented for the formation of azo-hydroperoxide compounds.