Rates and Mechanisms for Halide Anation Reactions of Platinum(IV) Complexes

• The bromide anation of tr-PtCl4BrH2O− has been studied at 25 °C and the chloride anations of tr-PtCl4BrH2O− and PtBr5H2O− at 50 °C. These reactions proceed via halide assisted mechanisms, compatible with the experimental rate laws determined. The bromide anation of tr-PtBr4CIH2O− studied at 50 °C gives PtBr5Cl2− via a bromide assisted path and PtBr62− via an REOA-path. The observed rate law is determined. PtBr5Cl2− reacts subsequently with bromide to form PtBr62− via a rate-determining (bromide assisted or REOA) formation of an intermediate aqua complex according to the mechanism given. The observed rate law at 50 °C is determined. All reactions have been studied in a 0.50 M perchloric acid medium. A general survey of reactivity correlations and mechanisms for platinum(IV) anation reactions is given. Effects of reductants, bridging and entering ligands, and of the four non-labile ligands in the plane around the platinum atom are quantitatively compared.

• The bromide anation of tr-PtCl4BrH2O− has been studied at 25 °C and the chloride anations of tr-PtCl4BrH2O− and PtBr5H2O− at 50 °C. These reactions proceed via halide assisted mechanisms, compatible with the experimental rate laws determined. The bromide anation of tr-PtBr4CIH2O− studied at 50 °C gives PtBr5Cl2− via a bromide assisted path and PtBr62− via an REOA-path. The observed rate law is determined. PtBr5Cl2− reacts subsequently with bromide to form PtBr62− via a rate-determining (bromide assisted or REOA) formation of an intermediate aqua complex according to the mechanism given. The observed rate law at 50 °C is determined. All reactions have been studied in a 0.50 M perchloric acid medium. A general survey of reactivity correlations and mechanisms for platinum(IV) anation reactions is given. Effects of reductants, bridging and entering ligands, and of the four non-labile ligands in the plane around the platinum atom are quantitatively compared.

Subject headings

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

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art (subject category)

ref (subject category)