Reversible Homogeneous Catalysis of Carbon Dioxide Hydrogenation/Reduction at Room Temperature and Low Pressures Mediated by Platinum(O)-Diphosphine Cluster Complex in Solution

摘要

A platinum complex, Pt2(u-PCP)3 (PCP = (C6H5)2PCH2P(C6H6)2, catalyzes the synthesis of N, N-dimehtylformamide (DMF) from CO2, H2 and (CH3)2NH in toluene solution at 25-100C and total pressures of 0.96-114 atm of the three reactant gases. The turnover numbers, DMF/complex/day, range from 9 at 25C and 0.96 atm to 1375 at 100 C and 114 atm. The homogeneous synthesis of DMF is readily reversible by either increasing the temperature, lowering the pressure of the reactants, or both, during the catalytic reaction. The formation of DMF appears to be dependent on the partial pressures of the individual reactants. Separate reactions of the three reactants with (Pt2(u-PCP)3) at ambient conditions (25C, 700 torr) give adducts with (CH3)2NH, but not with CO2 or H2. Keywords: Carbon Dioxide, Hydrogenation, Homogeneous Catalysis, N, N dimethylformamide, Platinum, Phosphine Complex.