Photoinduced reactions of organic compounds with transition metal complexes

Abstract

The photoinduced reaction of PtCl62− with alkyl derivatives of tin or germanium in acetic acid or acetone is described. The reaction with (CH3)4Sn affords the complex Ch3PtCl52− (I) whereas irradiation of PtCl62− with (CH3)2Sn(C2H5)2 leads to the formation of I and [(CH2CH2)PtCl2]2 (III). Complex III is formed in the reaction with Ge(C2H5)4. The proposed mechanism of “electrophilic” substitution by the platinum(IV) complex involves electron transfer from the tetraalkylmetal to the platinum(IV) complex and is labelled the SE1e.t. mechanism. The platinum(II)-ethylene complex III appears to be formed from CH3CH2PtCl52− (II) upon light irradiation via β-hydrogen elimination. The thermal reaction of PtCl62− with (CH3)4Sn to afford complex I is catalysed by PtCl42−. The thermal reaction of (CH3)4Sn with PtCl42− in acetic acid or aqueous acetone affords the σ-methyl complex of platinum(IV).