Reactions of Platinum(II) Complexes with Chloride-Based Oxidants: Routes to Pt(III) and Pt(IV) Products

This paper describes the oxidation of PtII(phpy)2 (phpy = 2-phenylpyridine) with two different electrophilic chlorinating reagentsPhICl2 and N-chlorosuccinimide (NCS). PtII(phpy)2 reacts with PhICl2 to provide the PtIV complex PtIVCl2(phpy)2 as a mixture of symmetrical and unsymmetrical isomers. In contrast, the reaction of PtII(phpy)2 with NCS affords a mixture of the PtIII dimer [(phpy)2(Cl)PtIII]2 and PtIVCl2(phpy)2, whose ratio varies as a function of reaction time, concentration, and the presence/absence of ambient light. The implications of these results for the mechanisms of the two reactions are discussed in detail.