SYNTHESIS AND REACTIVITY IN INORGANIC AND METAL-ORGANIC CHEMISTRY Vol. 33, No. 8, pp. 1459–1468, 2003 Heterobimetallic Complexes Containing Cu and Si K. S. Siddiqi, * Hina Afaq, Shahab A. A. Nami, and Ahmad Umar Department of Chemistry, Aligarh Muslim University, Aligarh, India ABSTRACT [Bis(propanediamine)Cu]Cl 2 ,(1) was allowed to react with SiCl 4 to yield a bimetallic complex (2). Compound (2) was then treated with pyridine to attain the maximum coordination number of silicon (3). The reaction was also followed conductometrically. Complex (3) was reacted with sodium diethyl dithiocarbamate (dtc) to yield (4). The dtc in (4) acts as a bidentate chelating agent as its IR spectrum showed the CS 2 stretching frequency at 1020 cm –1 which is characteristic of a symmetrically bonded dithiocarbamate group. There is a common peak in the range 246 to 260 nm in the UV-Vis. spectra of (1), (2) and (3) due to L ! M charge transfer. The EPR spectra of all species showed different environments for the Cu(II) ion in the various compounds indicating stereochemical changes. * Correspondence: K. S. Siddiqi, Department of Chemistry, Aligarh Muslim University, Aligarh, 202002, India; E-mail: ks_siddiqi@yahoo.co.in. 1459 DOI: 10.1081/SIM-120024322 0094-5714 (Print); 1532-2440 (Online) Copyright D 2003 by Marcel Dekker, Inc. www.dekker.com