Platinum complex, homolytic

As mechanistic hypothesis it was proposed (9-11) that the excited platinum complex undergoes homolytic Pt Cl cleavage affording a Ptm intermediate and an adsorbed chlorine atom (Scheme 1), by analogy with the known photochemistry of hexachloroplatinate in homogeneous solution (23,31). Electron injection from the platinum(III) complex into the titania conduction band reforms PtIv. Thus, the... 

Dialkylplatinum complexes with the cod ligand undergo photolysis at Amax>320nm in GD2CI2 (Scheme 10). The dimethylplatinum complex releases 1,5-dimethylcyclooctane 78 and Pt metal, while the analogs with two isopropyl or benzyl groups produce chloro(alkyl)platinum complexes 79 under the same conditions. Both products are formed via photochemically induced homolytic dissociation of a Pt-C cr-bond. 

The radical trap Bu NO has little effect on overall reaction rates and mechanism (a) therefore predominates. However, the radical BuKMe)NO can be detected so mechanism (b) must be operative to some extent. Attack of PhS- at the metal centre is considered to be the rate-determining step. Homolytic cleavage of platinum-(ii)-alkyl bonds also results when the complexes [PtRgl (R = CH3, CD3, or QH5 L = 2,2 -bipy R = Me, Lj = 1,10-phen or cyclo-octa-1,5-diene) are treated with diethyl fumarate, free alkyl radicals being detected by the radical trap Bu N==0. The reactions proceed according to the equations in Scheme 12. 

Morvillo and Turco have shown by H/D-labeling studies that platinum monoalkyl complexes /rans-[PtMe(I)(L)2] can decompose thermally by two pathways (L = phosphine). The initial step in the more important one is homolytic (145), the methyl radical so produced abstracting a hydrogen... 

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