Remarkable binuclear Schiff-based complex catalyze the epoxidation of alkenes: effects of substituent group

A series of dimolybdenum metal catalysts with different ligand have been successfully synthesized and used to catalyze the epoxidation of alkenes to generate epoxides by using tert-butyl-hydroperoxide (TBHP) as oxidant. The reaction condition was optimized by the adjustment of some key parameters, such as, temperature, to target high catalytic performance. The oxidation of cyclooctene gave 95.00% conversion and almost 100.00% selectivity. Kinetic study of the oxidation of cyclooctene under different temperature was taken out, indicating the reaction have good catalytic performance. Furthermore, it is calculated from the Arrhenius equation that different functional groups affect the activation energy of the reaction. The electron donor group substituent on the liagnd increases the catalytic activity by reducing the activation energy, and vice versa. Finally, a possible catalytic mechanism has been proposed by measuring the electronic absorption spectrum of the reaction.