Syntheses and crystal structures of diorganotin derivatives of 2,5-dimercapto-1,3,4-thiadiazole

Two novel trinuclear tin oxo clusters [(C2S3N2)R6Sn3O(OH)Y]L-. [R = CH3, Y = OH, L = 1(.)5H(2)O (1); R = PhCH2, Y = OEt, L = 0 (2)], a pentanuclear tin macrocycle [(CH3)(2)Sn (C2N2S3)](5)(.)CH(2)Cl(2)(.)3H(2)O (3) and [(PhCH2)(4)Cl2Sn(C2S3N2)] (4) have been synthesized by the reaction of 2,5-dimercapto-1,3,4-thiadiazole with dialkyltin dichloride in ethanol (95%) or dichloromethane. Complexes 1-4 have been characterized by elemental analysis and IR, H-1, C-13 and Sn-119 NMR spectroscopy. The structures of 1-3 have been determined by Xray crystallography. Complexes 1 and 2 display a unique tricyclic structure consisting of fused five-membered Sn2ON2 and four-membered Sn2O2 rings that form a planar N2Sn3O2 skeleton, with a distorted trigonal bipyramidal coordination at tin. Complex 3 is a pentanuclear 35-membered tin macrocycle containing the crown thioether-type ligand in which all five tin atoms bond to the sulfur and nitrogen atoms with distorted octahedral geometries. The structures of complexes 1 and 3 are stabilized by hydrogen bonds or intermolecular non-bonding (SS)-S-... interactions.