Crystal structure of μ-oxalato-κ 2 O 1 : O 2 -bis-[(dimethyl sulfoxide-κ O )tri-phenyl-tin(IV)].

In the previously reported [C2O4(SnPh3)2] complex [Diop et al. (2003 ▸). Appl. Organomet. Chem.17, 881-882.], the Sn(IV) atoms are able to formally complete their coordination by addition of dimethyl sulfoxide (DMSO) mol-ecules provided by the reaction medium, affording the title complex, [Sn2(C6H5)6(C2O4)(C2H6OS)2]. The Sn(IV) atoms are then penta-coordinated, with a common trans trigonal-bipyramidal arrangement. The asymmetric unit contains one half-mol-ecule, which is completed by inversion symmetry in space group type C2/c. The inversion centre is placed at the mid-point of the central bis-monodentate oxalate dianion, C2O4(2-), which bridges the [(SnPh3)(DMSO)] moieties. The mol-ecule crystallizes as a disordered system, with two phenyl rings disordered by rotation about their Sn-C bonds, while the DMSO mol-ecule is split over two positions due to a tetra-hedral inversion at the S atom. All disordered parts were refined with occupancies fixed of 0.5.