Addition of alcohols and water to Schiff bases co-ordinated to copper(II). Part II. The ligands NN′-bis-(2′-pyridylmethylene)propane-1,2-diamine and NN′-bis-(2′-pyridylmethylene)-2-methylpropane-1,2-diamine

Abstract

A study has been made of the reactions in which alcohol or water add to the azomethine group of the copper(II) compounds of the title quadridentate ligands. These have the same chelate ring skeleton as the ethylenediamine analogue, for which the addition reactions were first reported. And, in agreement with its suggested steric origin, the reaction also occurs for these new ligands. However, the solid products are now not invariably the addition products, and its is shown that the product depends, at least partially, on the solubilities of the various possible species, including the non-addition compounds. In addition, the reversibility of the reaction is demonstrated, and it appears that, in spite of the steric strain, the addition product and the non-addition product co-exist in solution in the alcohols. Isomeric forms of several of the compounds have probably been obtained.