Polyoxometalate on functionalized graphene sheets as a hybrid catalyst for efficient synthesis of benzimidazoles.

In this work, graphene oxide (GO) nanoparticles were synthesized and subsequently modified using 3-aminopropyltrimethoxysilane (APTMS). An Anderson-type polyoxometalate [(CH)N][CrMoO(OH)] was then immobilized on the surface of the modified graphene oxide nanoparticles. The obtained catalyst was characterized using Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDS), inductively coupled plasma (ICP), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD).

Efficient preparation of graphene oxide-immobilized copper complex and its catalytic performance in the synthesis of imidazoles.

This paper focused on the synthesis of phenylthiocarbamide-grafted graphene oxide (GO)-supported Cu complex (Cu-PTC@GO) as a highly efficient and recyclable catalyst synthesis by various analytical techniques such as TG, FT-IR, XRD, BET, N adsorption-desorption isotherms, SEM, EDX, and elemental mapping analysis. Cu-PTC@GO showed outstanding results in preparing various imidazoles with higher yields, reduced reaction time, ease of product separation, and a simple procedure. In addition, the catalyst demonstrated appreciable recyclability up to five successive runs, and there was no substantial loss in catalytic performance.