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]_n

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 N–H⋯Cl hydrogen bonds and layers are formed by additional intermolecular N–H⋯S hydrogen bonds. The crystal structure of 2 is characterized by intermolecular N–H⋯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 N–H⋯N intrachain hydrogen bonds and, overall a 3D network is formed by interchain N–H⋯N and N–H⋯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).