COMPARATIVE STUDIES OF SOLVATOCHROMISM BEHAVIOUR OF COPPER(I1) AND NICKEL(I1) SCHIFF BASE COMPLEXES

Abstract

A series of Schiff Bases of Ni(II) and Cu(II) using acetylacetone (acac),
salicylaldehyde (sal), ethylenediamine (en), and o-phenylendiarnine (dabe) were
prepared and characterized. The electronic spectra of some copper chelates in various
organic solvents depend strongly on the solvent used and the d-d band of Cu(II) shifts
to red with the increase of the Donor Number (DN) of solvent. The color changes from
blue to green are observed. The mechanism for solvatochromism is discussed in terms
of conformational changes and solvent coordination. Among the nickel complexes,
Ni (saloph) is brownish red in chloroform and green in pyridine, probably due to the
coordination of two pyridine molecules