1D POLYMERIC COPPER(II) COMPLEXES CONTAINING BRIDGING TRIDENTATE PYRAZINATO AND TERMINAL CHLORO OR AZIDO ANIONS - SYNTHESIS, SPECTRAL, STRUCTURAL AND THERMAL STUDY OF [CUCL(PYRAZINATO)(H2O)](N) AND [CU(N-3)(PYRAZINATO)(H2O)](N) COMPLEXES

The polymeric complexes [CuCl(pyrazinato)(H2O)](n) (1) and [Cu(N-3)(py razinato)(H2O)](n) (2) have been synthesized and characterized by spec troscopic methods and X-ray crystallography. The overall spectral resu lts indicate that these complexes contain tridentate pyrazinato ligand s, terminal chloride or azide groups and aqua molecules. In the struct ure of complex (1), each copper atom, which is chelated by O(1) and N( 1) atoms of the pyrazinato anions, links Cl(1) atom, O(3) atom from an aqua molecule and the second nitrogen, N(2) from a pyrazinato group o f a neighbouring unit giving rise to a 1D polymeric structure. The str ucture of complex (2), which is very similar to 1 features five coordi nate copper(II) atom, N, N,O-tridentate pyrazinato ligand, terminal az ido ligand, aqua molecule and 1D polymeric structure. There are differ ent types of hydrogen bonds in both complexes. The thermal decompositi on of complexes (1) and (2) was investigated thermogravimetrically in nitrogen atmosphere. (C) 1998 Elsevier Science Ltd. All rights reserve d.