Six-polynuclear complexes bridged by N-heterocycle, of formula [Ni(salal)2(4,4'-bipy)]n, [Ni(Et-dtp)2(4,4'-bipy)]n, [Cu(acac)2(4,4'-bipy)]n、[Cu(TTA)2(pyz)]n, [Cu(TTa)(Im)]n and [Cu(Im)2]n, were synthesized and characterized by elemental analysis, IR, MS, ESR and thermogravimetric analysis, Crystal structure analysis has proved that the complex [Cu(TTA)2(pyz)]n has one-dimensional infinite linear structure. The local coordination geometry around Cu(II) is a distorted octahedron. The variable-temperature magnetic susceptibility determinations show that the magnetic properties of 4,4'-bipyridine and pyrazine bridging complexes obey the Curie-Weiss law. The imidazole complexes have strong antiferromagnetic interactions, the parameters 2J=-75cm^-^1 for [Cu(TTA)(Im)]n and -107cm^-^1 for [Cu(Im)2]n. Magnetic experimental data are discussed in the relation to the structures of 4,4'-bipyridine, pyrazine and imidazole. It is shown that 4,4'-bipyridine is not a good bridge for propagating a magnetic exchange interaction between n=metal ions.

Key words: INFRARED SPECTROPHOTOMETRY, ELEMENTAL ANALYSIS, MASS SPECTROGRAPHY, IMIDAZOLE, COPPER COMPLEX, THERMOGRAVIMETRY, NICKEL COMPLEX, ELECTRON SPIN RESONANCE, BIPYRIDINE, MAGNETISM