A copper-phosphonate network as a high-performance heterogeneous catalyst for the CO2 cycloaddition reactions and alcoholysis of epoxides

Abstract

A novel 3D copper-phosphonate network, with the general formula Cu₇(H₁L)₂(TPT)₃(H₂O)₆, namely compound 1, has been synthesized using a rigid tetrahedral linker tetraphenylsilane tetrakis-4-phosphonic acid (H₈L) and a nitrogen-containing ancillary ligand (TPT: [5-(4-(1H-1,2,4-triazol-1-yl)phenyl)-1H-tetrazole]) under hydrothermal conditions. The compound was fully characterized using PXRD, ICP, IR, TGA and elemental analysis. Compound 1 can be used as an efficient catalyst for the CO₂ coupling reaction that is greatly superior to many conventional MOF-based catalysts, where porosity is always mentioned and used. In addition, it shows excellent catalytic performance for ring-opening reactions with epoxides under ambient conditions. Additionally, compound 1 can be recycled at least three times without a significant compromise in the activity in the two catalytic reactions.