A two-fold interpenetrating metal-organic framework based on [Co4O(COO)6] cluster: Synthesis, crystal structure and catalytic properties

One new Metal-Organic Frameworks, [Co4O(L)2]·(DMF)8·(H2O)8 (1, H3L = 4-[N,N-bis(4-methylbenzoic acid)amino]benzoic acid), had been successfully constructed under hydrothermal conditions, which firstly presents the [Co4O(COO)6] secondary-building unit similar to the typical [Zn4O(COO)6] one via single-crystal X-ray diffraction studies. All of the cobalt ions exhibit the four-coordinate environment, and possess more open metal sites. Heterogeneous catalytic experiments on allylic oxidation of cyclohexene indicate that 1 exhibits high catalytic activity by utilizing the tert-butylhydroperoxide (t-BuOOH) as the oxidant. The activation energy for the whole process of oxidation of cylcohexene had been calculated as 40.6 kJ mol−1, which indicate the important role of the special [Co4O(COO)6] cluster in the resulted heterogeneous catalyst.