New complexes of Cu(II), Co(II), and Ni(II) with bis(salicylidene)hydrazone have been obtained. It has been shown that bis(salicylidene)hydrazone forms bi-nuclear complexes with the ions of these metals. The structure and physicochemical properties of these complexes have been studied by IR, UV spectroscopy, EPR and thermogravimetric analysis. IR spectra show that coordination of ligand with metal ion is carried out through oxygen atom of phenolic group and nitrogen atom of C=N group. In the electronic spectra of the ligand there are absorption bands of the aromatic ring transition at ~240 and 290 nm (related to π→π* and n- π transitions). The absorption bands at 340 and 380 nm can be attributed to the absorption of the azomethine group conjugated to the benzene ring. On the basis of thermogravimetric analysis the stages of thermal decomposition of synthesized complexes and the composition of solid reaction products obtained at these stages have been determined. It has been shown that the final products of thermal decomposition consist of Co, Ni, Cu oxides. In the EPR spectrum of the copper complex a very weakly asymmetric signal with g=2.10 is observed, which may indicate a tetrahedral (pseudotetrahedral) structure of the complex

doi.org/10.32737/0005-2531-2023-2-116-122