Synergistic effect of GO/SrFe12O19 as magnetic hybrid nanocatalyst for regioselective ring-opening of epoxides with amines under eco-friendly conditions.

Abstract

Herein, a highly efficient magnetically separable hybrid GO/SrFe12O19 nanocomposite was synthesized via dispersing M-type strontium hexaferrite (SrFe12O19) on graphene oxide (GO) sheets. First, SrFe12O19 nanoparticles (NPs) and GO sheets were prepared via chemical coprecipitation and chemical oxidation of graphite powder, respectively. Chemically reduced GO (rGO) and rGO/SrFe12O19 were also prepared for comparison purposes. Thereafter, the prepared nanostructured materials were explored by XRD, FTIR, FESEM-EDX, BET, and Zetasizer analyses. All the characterizations confirm the nanoscale and the high stability structures of the prepared materials. The prepared hybrid magnetic nanocomposite GO/SrFe12O19 exhibited a high surface area value resulting in a high catalytic activity and selectivity for the epoxide ring-opening with amines in neat water. The use of hybrid GO/SrFe12O19 compared with pure SrFe12O19 and GO sheets is of great interest for using environmentally benign heterogeneous nanocatalysts, for the synthesis of β-amino alcohols, with excellent recyclability under eco-friendly conditions. Moreover, a mechanistic study was performed through density functional theory (DFT) calculations and Parr functions to explain the observed reactivity and selectivity of SrFe-GO catalyst in the epoxide ring-opening reactions.