Synthesis and crystal structures of cadmium(II) complexes of 1,3-diazinane-2-thione (diaz); [Cd(diaz)4Cl2], [Cd(diaz)2(NCS)2] and [Cd(diaz)2(N3)2

Abstract

Three cadmium(II) complexes of 1,3-diazinane-2-thione (diaz); dichloridotetrakis(1,3-diazinane-2-thione)cadmium(II), [Cd(diaz)4Cl2] (1), bis(thiocyanato-κN)bis(1,3-diazinane-2-thione)cadmium(II), [Cd(diaz)2(NCS)2] (2) and poly[diazidobis(1,3-diazinane-2-thione)cadmium(II)], [Cd(diaz)2(N3)2]n (3) were prepared and their crystal structures were determined by X-ray crystallography. The compounds 1 and 2 exist in the monomeric forms as discrete nonionic molecules. In 1, the cadmium atom is octahedrally coordinated by two trans chloride ions and four diaz ligands, while in 2, it is bound to two thione molecules and two thiocyanato ions through nitrogen atoms in a tetrahedral environment. The structure of 1 is stabilized by intramolecular NH⋯Cl hydrogen bonds and layers are formed by additional intermolecular NH⋯S hydrogen bonds. The crystal structure of 2 is characterized by intermolecular NH⋯S hydrogen bonding and S⋯S interactions. The complex 3 exists in the form of a polymeric chain consisting of [Cd(diaz)2(N3)2] units. In 3 each cadmium atom is octahedrally coordinated by two trans diaz ligands and four doubly-bridging, µ(1,3) azide groups. The coordination chain is stabilized by additional NH⋯N intrachain hydrogen bonds and, overall a 3D network is formed by interchain NH⋯N and NH⋯S hydrogen bonds. The complexes 1–3 were also characterized by IR and NMR spectroscopy, and the spectroscopic data indicated the coordination of ligands to cadmium(II).