Syntheses and properties of mixed dinuclear copper(II) complexes with heterocyclic dithiocarbamates and a cyclic octadentate tertiary amine

Abstract

Five new CuII complexes of general formula [Cu2(Rdtc)tpmc](ClO4)3, (1)–(5), where tpmc and Rdtc− refer to N,N′,N′′,N′′′-tetrakis(2-pyridylmethyl)-1,4,8,11-teraazacyclotetradecane and piperidine- (Pipdtc), 4-morpholine- (Morphdtc), 4-thiomorpholine- (Timdtc), piperazine- (Pzdtc) or N-methylpiperazine- (N-Mepzdtc) dithiocarbamates, respectively, have been prepared. Elemental analyses, conductometric and magnetic measurements, u.v./vis, i.r., e.p.r. and mass spectroscopy have been employed to characterize them. The complexes adopt an exo coordination of CuII ions and tpmc. The dithiocarbamate ion joins both the sulphur and the copper atoms acting as a bridging ligand The presence of different heteroatoms in the piperidine ring influences the ν(C=N) and ν(C=S) vibrations which decrease in the order of the complexes: Pipdtc > N-Mepipdtc > Pzdtc > Morphdtc > Timdtc ligands. Attention has been paid to the detailed mechanism of the mass spectral fragmentation of the complexes. The geff factors of the complexes have been also estimated by e.p.r. spectra. Finally, the complexes obtained demonstrate microbiologycal activity against some bacteria.