Selective Light Induced Cyclometalation in trans-(MesPh(2)P)(2)PtCl2

Reaction of mesityl diphenylphosphine (1) with PtCl2(cod) at room temperature afforded trans-PtCl2[(1)](2) (2). Using K2PtCl4 as starting material in refluxing mesitylene, the cyclometalated complex trans-PtCl[(1)(1-H)] (3) was isolated. Irradiation of complex 2 in dichloromethane with sunlight for 5 h provided a mixture of complexes 2 and 3 in a 1: 4 ratio. The structures of 2 and 3 were established by X-ray crystallography.