Copper(II) complex intercalated graphene oxide nanocomposites as versatile, reusable catalysts for click reaction

In this work, we report the efficient, high stable copper(II) complexes intercalated graphene oxide (GO) used as green catalysts for copper(II) complex mediated click reaction. Copper(II)Bis(2,2 '-bipyridine) [Cu-II(bpy)(2)] (C1) and Copper(II)Bis(1,10-phenanthroline) [Cu-II(phen)(2)] (C2) have synthesized for the intercalation of corresponding nanocomposites with GO, [GO@Cu-II(bpy)(2)] (GO-C1) and [GO@Cu-II(phen)(2)] (GO-C2). The noncovalent interaction of complexes supported on the surface of the GO nanosheets proves as an evident active site to facilitate the enhanced catalytic activity of copper-catalyzed alkyne azide cycloaddition (Cu(II)AAC) reaction for the isolation of 1,4-disubstituted-1,2,3-triazoles as click products in shorter reaction time with 80%-91% yield (five examples). The X-ray diffraction (XRD) pattern of these composites shows the enhanced interlayersd-spacing range of 1.01-1.12 nm due to the intercalation of copper(II) complexes in between the GO basal planes and characterized by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), Raman, UV, scanning electron microscope (SEM), and thermogravimetric analysis (TGA). The as-prepared nanocomposites were employed for the typical click reactions using the substrates of azide and acetylene. These classes of composite materials can be referred to recyclable, heterogeneous, green catalysts with high atom economy and could also be used for the isolation of click products in biomolecules.