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 β‐diketonate li‐gands to give [Pt( O,O′ ‐acac)(γ‐acac)L] species. The new com‐pounds 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)(γ‐acac)(DMSO)] ( 2 ), have been synthesised and characterised by 1 H, 13 C, 195 Pt 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)(γ‐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 β‐diketonate li‐gands to platinum( II ) complexes, where the first species formed contains one O,O ′ ‐chelated acac group. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)