A new metal organic complex with coordination unsaturated Co(II) as high-efficiency heterogeneous catalyst for selective oxidation of alkylbenzenes

Converting C-H bonds into valuable compounds is a challenging goal in synthetic chemistry, yet it is both economically and environmentally beneficial. Developing high-efficiency catalysts for the oxidation of saturated C-H bonds is of great significance. Herein, a new cobalt-containing metal-organic complex, [Co-2(L)(0.5)(MTC)(mu(3)-OH)(H2O)(2)]center dot 2H(2)O (1, L = (E)-4,4'-(ethene-1,2-diyl)bis(N-(pyridin-3-yl)benzamide), H3MTC = benzene-1,2,4-tricarboxylic acid), was successfully prepared with Co(NO3)(2), ligand L and H3MTC through one-step hydrothermal synthesis. Complex 1 was found to be a highly effective heterogeneous catalyst for accelerating the oxidation reaction of alkylbenzenes to ketone products. The conversion of diphenylmethane to benzophenone over complex 1 was 95.6%, which was comparable to the highest values of reported transition metal-based catalysts. A possible catalytic reaction mechanism was proposed.