Imine-linked conjugated organic polymer bearing bis(imino)pyridine ligands and its catalytic application in C–C coupling reactions

Covalent organic polymers are an emerging class of materials with potential applications in areas including molecular separation, gas sorption, and catalysis. A novel fully conjugated organic polymer bearing bis(imino)pyridine (COP-BIP) and its catalytic function are reported here. Unlike previous COP materials, the imine bonds of COP-BIP act as both linkages and complexation sites for the binding of metal ions. A clear structure is presented based on ultraviolet-visible, Fourier transform infrared, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry characterization. The COP-BIP materials are thermally stable up to 440 °C and are insoluble in conventional solvents. In addition, COP-BIP complexes Pd ions on bis(imino)pyridine sites and forms a heterogeneous catalyst, which exhibits excellent catalytic activity in the Suzuki-Miyaura C–C coupling reaction.

Graphical AbstractA conjugated organic polymer linked by imine bonds bearing bis(imino)pyridine (COP-BIP) was synthesized for the first time. The formation process and the precise structure was determined by MALDI-TOF mass spectrometry. COP-BIP showed highly thermal stability up to 440 °C and was insoluble in conventional solvents. It functioned as a ligand for Pd ion and formed a heterogeneous catalyst during the Suzuki-Miyaura C–C coupling reaction.Figure optionsDownload full-size imageDownload as PowerPoint slide