Molecular design of new magnetically active copper complexes with heteroaromatic Schiff bases and azo compounds

Copper chelates with tridentate ligands containing pyridine or pyrazole ring at the azomethine or azo fragment were synthesized by chemical electrochemical methods, and their structure was characterized by the EXAFS spectra. Thermal rnagnetochemical analysis of the complexes revealed anti ferromagnetic exchange interaction in all complexes. The exchange interaction parameter of the complex containing an N-tosylamino C7 C oroup in the ortho position with respect to the azomethine aroup is much lesser than that of the corresponding complex having an oxygen atom in the same position. The copper chelate derived from azopyrazole ligand C! shows low-temperature ferromagnetic phase transition.