Synthesis and characterization of antimony(III) complexes of thioamides, and crystal structure of {[Sb(Imt)₂Cl₂] ₂(μ(₂-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)_nCl₃ (n=1, 2, 2.5, 3) were prepared and characterized by elemental analysis, IR and NMR (¹H, ¹³C) 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)₂Cl₂] ₂(μ₂-Imt)}Cl₂ (1), was determined by X-ray crystallography, which shows that the complex is dinuclear consisting of two [Sb(Imt)₂Cl₂] 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.