Kinetics and mechanism of 1-phenylethanol oxidation by the system hydrogen peroxide-manganese(IV) binuclear complex-oxalic acid

摘要

Hydrogen peroxide was found to oxidize 1-phenylethanol to acetophenone in acetonitrile homogeneous solution efficiently at room temperature in the presence of a dimeric complex of manganese (IV) [LMn(O)_3MnL](PF _6)_2(where L = 1,4,7-trimethyl-1,4,7-triazacyclononane) as the catalyst and oxalic acid as a co-catalyst. The number of catalytic cycles was 15 000 3 h after the onset of the reaction. The dependences of the initial rate of acetophenone accumulation on the initial concentrations of the reagents were studied. Based on an analysis of the kinetic data, we conclude that phenylethanol is oxidized by a manganyl particle containing an Mn = O fragment that interacts competitively with hydrogen peroxide.