Constructing a Redox-Active Cu(I)-Pyridyltriazine Framework for Catalytic Photoreduction of Nitrobenzenes and Carboxylic Cyclization of Alkynol with CO2

A redox-active metal-organic framework, Cu(I)-TPT, was synthesized by combination of Cu(I), the halogenoid cyanide group (CN), and redox-active organic bridging ligand 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) into one single framework. Cu(I)-TPT displays a two-dimensional (2D) plane structure by 1D-Cu(I)-CN- chains connected with TPT ligands. Cu(I)-TPT exhibits intrinsic semiconductive features with a moderate bandgap energy (1.97 eV). Under irradiation, Cu(I)-TPT has an electrical conductivity of 2 x 10-7 S cm-1 in the presence of the sacrificial electron donor ethanol under the ambient test conditions, which is owing to the ir-ir stacking interactions between TPT moieties, the d-ir conjugation between the Cu(I) ion and the CN ligands, and the permanent microporosity. Cu(I)-TPT displayed highly efficient hole- electron separation and ordered electron transfer, which is beneficial for the photoreduction of nitrobenzene. In addition, Cu(I)-TPT displays high efficiency in carboxylic cyclization of alkynol with CO2 because it possesses highly decentralized Cu(I) catalytic sites to the active CC bond of alkynol and affluent N atoms on the 2D sheets to facilitate the trapping and activation of CO2.

Automated summary

Cu(I)-TPT is a redox-active metal-organic framework with a planar structure, moderate bandgap energy, and intrinsic semiconductor properties. It exhibits high efficiency in photoreduction and carboxylic cyclization reactions.