Novel salenCo(iii) photoinitiators and their application for cycloaddition of carbon dioxide.

Carbon dioxide (CO) is a renewable carbon resource that can be effectively used in the production of polycarbonate (PPC) and cyclic carbonate (CPC) through open-loop copolymerization with epoxides and CO. SalenCo(iii) can successfully break the carbon-oxygen link between propylene oxide (PO) and CO. On this basis, we prepared four different types of photosensitive salenCo(iii) complexes and investigated their catalytic copolymerization of CO and PO. The results show that the catalytic performance of 1,2-cyclohexamediamine complexes is better than that of 1,2--phenylenediamine complexes. The catalytic efficiency of salenCo(iii) catalyst increases with the expansion of the photosensitive conjugate system. In addition, the introduction of light can improve the catalytic efficiency. When we increased the power of the external light source from 100 W to 200 W, the TON of the catalyst [C4] increased by nearly 50%.