Surface-decorated magnetite nanoparticles with dioxidomolybdenum(VI) complexes as a catalyst for alkene epoxidation

• Two novel homogeneous and supported molybdenum complexes were synthesized. • These compounds were used in the catalytic epoxidation of alkenes. • Catalytic performance was compared between thermal and microwave methods. • The supported catalysts exhibited superior activity compared to other catalysts. Two dioxidomolybdenum(VI) complexes, denoted as [(MoO 2 ) 2 (L 1 )] 1 and [(MoO 2 ) 2 (L 2 )] 2, were successfully synthesized and characterized. Subsequently, these complexes were immobilized onto the surface of Fe 3 O 4 @SiO 2 -NH 2 , yielding supported compounds [(MoO 2 ) 2 (L 1 )]@Fe 3 O 4 @SiO 2 -NH 2 3 and [(MoO 2 ) 2 (L 2 )]@Fe 3 O 4 @SiO 2 -NH 2 4. A range of analytical techniques was employed to thoroughly characterize all synthesized compounds. The effectiveness of the developed supported catalysts in catalyzing the epoxidation of alkenes with hydrogen peroxide (H 2 O 2 ) as the oxidant was assessed. Moreover, the magnetic properties of the supported compounds were assessed before and after catalytic reactions. It was observed that the magnetic properties exhibited slight alterations following the catalytic cycles. Remarkably, the supported catalysts demonstrated remarkable performance, affording excellent conversion rates along with favorable selectivity towards epoxide products. In addition, the catalysts were found to be reusable for up to seven successive cycles in the transformation of olefins and could be effectively recovered from the reaction mixture using an external magnet.