Ligating properties of model bioheterocyclics—I: Complexes of copper(II) and cobalt(II) halides with 3,6-disubstituted-2,7-dihydro-1,4,5-thiadiazepine derivatives

Abstract

Copper(II) and cobalt(II) halides react with 3,6-disubstituted-2,7-dihydro-1,4,5-thiadiazepine derivatives(L) to form highly hygroscopic complexes of the general formulae, [(CuCl 2) 2L] 2nH 2O; [(CuBr 2) 3L 2]nH 2O and [CoX 2L] 2nH 2O respectively. On the basis of analytical, reflectance, paramagnetic susceptibility and molar conductance measurements, Cu(II) chloride and bromide complexes have been assigned dimeric and monomeric structures in which bridging through halogens and thiadiazepine ring takes place. These complexes are mixtures of stereoisomeric forms of square planar and distorted tetrahedral geometries. Co(II) complexes have been shown to possess tetrahedral geometry with dimeric structure in which bridging through only thiadiazepine ring occurs. Thermal stabilities, IR and PMR data is also reported. Here L acts as a bridging bidentate ligand by coordinating through two adjacently placed nitrogen atoms.