Synthesis, molecular structure and computational study of a ruthenium bis(thietane) complex

Dissolution of [CpRu(PPh3)(SC4H8)2]CF3SO3 in thietane/CH2Cl2 with stirring yields the title compound [CpRu(PPh3)(SC3H6)2]CF3SO3 (I). The single crystal X-ray structure shows a disparity in the puckering of the two thietanes. One thietane ligand is near-planar, with torsion angles of ±1.5(5)° for CSCC and ±1.8(4)° for CCCS; the second thietane ligand of I has torsion angles of ±21.0(4)° for CSCC and ±25.0(3)° for CCCS. Compound I contains both the largest and the smallest torsion angles for any complex reported. Theoretical calculations were carried out for both thietane and for I using the gamess and gaussian 98 packages.