Synthesis and Characterization of Antimony(III) Complexes of Thioamides, and Crystal Structure of {[Sb(Imt)2Cl2]2(μ2-Imt)}Cl2 (Imt=Imidazolidine-2-thione)

Antimony(III) complexes of thioamides [thioamides=thiourea (Tu), N,N'-dimethylthiourea (Dmtu), tetramethylthiourea (Tmtu), imidazolidine-2-thione (Imt) and diazinane-2-thione (Diaz)] with the general formulae, Sb(thione)(n)Cl-3 (n=1, 2, 2.5, 3) were prepared and characterized by elemental analysis, IR and NMR (H-1, C-13) spectroscopic methods. The spectral data of the complexes are consistent with the coordination of the thiones to antimony( III). The crystal structure of one of them, {[Sb(Imt)(2)Cl-2](2)(mu(2)-Imt)}Cl-2 (1), was determined by X-ray crystallography, which shows that the complex is dinuclear consisting of two [Sb(Imt)(2)Cl-2] units bridged by an Imt molecule. In 1, the antimony atom is bonded to two chlorine atoms, two sulfur atoms of coordinated Imt molecules and one sulfur atom of a bridging Imt molecule. The antimony environment can be considered to be distorted octahedral with one Cl ion weakly bound to antimony.