Synthesis of reduced graphene oxide-based catalytic complexes for benzylamine–o-phenylenediamine oxidative coupling

Abstract

Two hydrazone-based dioxidomolybdenum(VI) complexes, [MoO₂(HMB-SA)·H₂O] (1) and [MoO₂(HMB-OV)·H₂O] (2), were prepared along with reduced graphene oxide-supported complexes [MoO₂(HMB-SA)·H₂O]@rGO (3) and [MoO₂(HMB-OV)·H₂O] @rGO (4). The supported Mo complexes were characterized by FT-IR, P-XRD, FE-SEM/EDS, HR-TEM, BET, and XPS. A deformed octahedral geometry enclosing the molybdenum center was verified by single-crystal X-ray diffraction analysis of the homogeneous complexes. All complexes demonstrated high efficiency in the oxidative coupling of benzylamine in a green solvent, consistently affording excellent benzimidazole product yields. For at least four consecutive cycles, the assisted catalysts maintained their catalytic efficacy without decreasing activity.