The activation of saturated hydrocarbons by transition-metal complexes in solution. Part II. Hydrogen–deuterium exchange in saturated and unsaturated hydrocarbons catalysed by solvated platinum(II) chloro-complexes

Abstract

Exchange of hydrogen for deuterium in alkanes and in aromatic hydrocarbons is catalysed by platinum(II) chloro-complexes in acetic [²H₁]acid–deuterium oxide mixtures at ca. 100 °C. Solutions of chloro-complexes having Cl:Pt ratios in the range 4·0–2·3 have been used. The effects on the exchange process of hydrocarbon concentration, solvent composition, and catalyst composition are reported. The rate constant for exchange varies exponentially with the adiabatic ionisation potential of the hydrocarbon. This correlation breaks down for certain aromatic hydrocarbons when Cl:Pt < 4 owing to extensive complex formation between reactant and catalyst; values for the formation constants of such complexes are reported.