A new Co(II)-Schiff base complex was decorated on a polysalicylaldehyde
(PSA) framework and used as a selective and efficient catalyst for the epoxidation of
alkenes in the presence of O2 as a green source of oxygen without aco-reductant. The
catalyst was characterized step by step by FTIR, UV–Vis, 1H NMR, TGA, CHN, XPS
and EDX analyses. Loading an amount of Co ions in the catalyst as well as its leaching
amount were studied by an ICP-OES instrument. The catalyst demonstrated excellent
activity for the of a variety of alkenes in a mild, inexpensive and efficient protocol. Also,
the catalyst can be simply recovered from the reaction mixture and reused for several
times without any noteiceable loss in its activity. Reaction parameters including temperature,
oxygen flow volume, catalyst amount and solvent were screened by reaction
time. Catalytic studies including XPS spectroscopy and some blank experiments were
performed to obtain an initial insight into the reaction mechanism. Also, the reactivity of
the novel catalyst was evaluated as the turnover frequency.
کلید واژگان :
Epoxidation Polysalicylaldehyde Self-coreductant Solid support Co-polymeric Schiff base complexes
