First examples of β-diketonate platinum(II) complexes with sulfoxide ligands

New platinum(II) complexes have been prepared as models for explaining the coordination of multiple beta-diketonate ligands to give [Pt(O,O'-acac)(gamma-acac)L] species. The new compounds containing both an O,O'-chelated acetylacetonate ligand and a sulfoxide in the platinum coordination sphere, [PtCl(O,O'-acac)(DMSO)] (1) and [Pt(O,O'-acac)(gamma-acac) (DMSO)] (2), have been synthesised and characterised by H-1, C-13, Pt-195 1-D and 2-D NMR heteronuclear correlation spectroscopy and, in the case of 2, by X-ray crystal structure analysis also. Moreover, a new synthetic pathway to obtain the previously reported complex K[Pt(O,O'-acac)(gamma-acac)(2)] (3) has been developed. The data presented herein are consistent with a reaction mechanism which explains the subsequent steps of the coordination of multiple-diketonate ligands to platinum(II) complexes, where the first species formed contains one O,O'-chelated acac group. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.