Flexible covalent porphyrin framework film: An emerged platform for photocatalytic C[sbnd]H bond activation

Abstract

Photocatalysis is one of the most promising ways for the production of organic chemicals with renewable energy source. For the development of cost-effective and metal-free catalysts, two-dimensional covalent organic framework (COF) has been emerged as a photocatalyst. Here, we report the synthetic method of two-dimensional covalent porphyrin framework (2D CPF) and the fabrication procedure of highly active flexible film. 2D CPF were constructed from tetrakis-(4-amino-phenyl)-porphyrin (TAPP) and tetrakis-(4-nitro-phenyl)-porphyrin (TNPP) monomers through the poly-condensation reaction and the resultant composite showed the superb harvesting ability of solar light, the suitable optical band-gap, and the highly ordered π-electron channels which facilitates efficient charge migrations. The 2D CPF photocatalyst deposited on the thin film was readily applicable to light-induced activation of CH bond between p-position of substituted aryl diazonium salts and heteroarenes, and exhibited the high selectivity (~99%) as well as high production yield. Our results show an experimental benchmark for the use of flexible COF film as a highly practical and efficient solar light responsive photocatalyst for the selective CH bond formation in between substituted aryl diazonium salts and heteroarenes derivatives.