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The kinetic isotope effects (KIEs), k H /k D , have been determined for reaction of CH 3 I/CD 3 I with several organoplatinum(II) complexes [PtR 2 (NN)], in which the bidentate NN ligand is bpy=2,2 0 -bipyridine, t Bu 2 bpy=4,4 0 -bis(tert-butyl)-2,2 0 -bipyridine, phen=1,10-phenanthroline, or Me 2 phen=2,9-dimethyl-1,10-phenanthroline, at different temperatures and in solvents having different polarities. The values obtained for the secondary R-deuterium KIEs are close to 1 and are dependent on the solvent; values of up to 7-10% larger are obtained for the reactions in the polar solvent acetone as compared to those obtained in the nonpolar solvent benzene. The data also indicate that the steric crowding around the squareplanar coordination sphere of the platinum(II) complexes with the ligand Me 2 phen results in higher KIEs. The reactions involving dimethylplatinum(II) complexes, [PtMe 2 (NN)], were fast, and a 1:1 molar ratio (of complex and reagent) technique was successfully used to measure the rate constants accurately by conventional UV-visible spectroscopy. It is shown that there are significant advantages to measuring the reaction rates under second-order condition, as compared to the usual pseudo-first-order method.

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The synthesis of the two cycloplatinated(IV) complexes [PtMe(OAc) 2 (C ∧ N)(H 2 O)] (C ∧ N = 2-phenylpyridinate (2a), benzo[h]quinolate, 2b) by reaction of [PtMe(C ∧ N)(SMe 2 )] with PhI(OAc) 2 is described. Complexes 2 undergo carbon− oxygen bond forming reductive elimination instead of C−C reductive elimination to produce MeOAc as protected methanol. The kinetics and mechanism of both Pt−O bond formation and C−O reductive elimination have been experimentally and theoretically investigated. The results suggest that formation of methyl acetate proceeds via nucleophilic attack of the dissociated acetate ligand at the methyl group carbon in a cationic five-coordinate intermediate cycloplatinated(IV) complex.