آتنا نعیمی

In the present paper, the catalytic activity of a dioxo-molybdenum (VI) unsymmetrical Schiff base complex immobilized on CoFe2O4@SiO2 core– shell nanoparticles (CoFe 2O4@SiO2@[MoO2(salenac-OH)] where salenac- OH = [9-(2’,4’-dihydroxyphenyl)-5,8-diaza-4-methylnona-2,4,8-trienato](-2)) was studied in the selective oxidation of alcohols using tert-BuOOH (TBHP, 70% aque- ous solution) as an oxidant. In this catalytic system, the contribution of different solvents was investigated, and it was found that the various primary and second- ary alcohols were oxidized to their equivalent aldehydes and ketones with good to excellent yields (64–97%) at ambient temperature under solvent-free conditions. Moreover, the effect of other essential factors such as the type of oxidant and the quantity of catalyst on the oxidation of benzyl alcohol was explored. Among dif- ferent oxidants such as H 2O2, urea/H 2O2 (UHP), tert-BuOOH (TBHP) and NaIO 4, tert-BuOOH was selected as oxygen donor, and the oxidation of benzyl alcohol required 50 mg (0.0135 mmol Mo) of catalyst to complete. The CoFe 2O4@SiO2@ [MoO2(salenac-OH)] catalyst can be conveniently removed from the reaction mix- ture by using an external magnet and reused four times without notable loss of its catalytic performance. Besides, comparing the X-ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectrum, scanning electron microscopy (SEM) image, and energy-dispersive X-ray (EDX) analysis of the recycled catalyst with fresh catalyst showed no significant difference, proving that the catalyst structure remained intact after recovery.