Structure of (dimethyl sulfoxide‐S){glyoxylic acid thiosemicarbazonato(2–)‐O,N,S }platinum(II)

A crystal of the title complex [Pt(DMSO)(GT)] ( 1a ), where H₂GT = glyoxylic acid thiosemicarbazone, has been characterized by X‐ray crystallography and its structure has been compared with that of the recently described cytotoxic complex [Pt(DMSO)(GT)]·DMSO (1). The crystal of 1a is monoclinic; space group P 2₁/n; unit cell dimensions: a = 7.3270(10), b = 10.313(2), c = 13.706(3) Å, β = 101.92(3)°; V = 1013.3(3) ų; Z = 4. The Pt(II) ion is approximately planar tetragonal coordinated by the carboxylato oxygen, azomethine nitrogen and thiolato sulfur atom of the doubly deprotonated H₂GT molecule, and the sulfur atom of DMSO. The two five membered chelate rings are almost coplanar. In distinct with 1 , the sulfoxide oxygen atom and thiolato sulfur atom are in gauche position. A system of hydrogen bonds of the type N–H···O involving the amino, carboxylato and sulfoxide groups links the complex molecules within the unit cells. The π ‐π stacking pattern between the chelate rings in 1a involves centrosymmetric pairs of complex molecules and differs from that in 1 . (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)