Cu(II)-Based Metal–Organic Framework Loaded with Silver Nanoparticles as a Catalyst for the A3-Coupling Reaction

The embedding of metal nanoparticles (NPs) in metal–organic frameworks (MOFs) has attracted a wide range of attention in the field of catalysis due to the high agglomeration resistance of NPs in MOFs. In this work, a Cu(II)-based MOF with the formula {[Cu1.5(TPA)(BIBT)]·4DMF·6H2O]}n (1) (H3TPA = tris(4′-carboxybiphenyl)amine; BIBT = 4,7-di(1H-imidazol-1-yl)benzo[c][1,2,5]thiadiazole; and DMF = N,N-dimethylformamide) was synthesized under solvothermal condition. Structural analysis revealed that Cu-MOF 1 possessed 3-fold interpenetrated three-dimensional (3D) coordination frameworks with large one-dimensional (1D) channels along the a-axis. Due to the interaction between Ag and S/N, Ag NPs could be encapsulated into the pores of Cu-MOF 1 to generate Ag NPs and MOF composites, xAg/1 (x = 0.3, 0.5, 0.8, and x was the molar ratios of AgNO3 with Cu-MOF 1 in the synthesis), which was further demonstrated by powder X-ray diffraction, Fourier transform infrared, scanning electron microscopy, transmission electron microscope, energy dispersive spectrometer, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller (BET) analysis. In addition, synthesized 0.5Ag/1 exhibited outstanding catalytic activity for the A3-coupling reaction of aldehyde, alkyne, and amine with high recyclability. This work presents a viable strategy for using Cu(II)-based MOF loading with Ag NPs as heterogeneous catalysts for the A3-coupling reaction.