Donor-acceptor conjugated porous polymers from truxene and triazine: Effect of connecting units on photocatalytic activity for selective oxidation of amines and sulfides

Donor-acceptor (D-A) conjugated polymers have been widely reported as promising photocatalysts for organic conversion. However, achieving excellent photocatalytic performance still relies on the rational design of molecular structures and the careful selection of appropriate building blocks. In this study, we designed two D-A type conjugated porous polymers (CPPs) using 2,7,12-tribromo-5,5,10,10,15,15-hexamethyl-10,15-dihydro-5Hdiindeno[1,2-a:1 ',2 '-c]fluorene (Tx) as the donor unit and two 1,3,5-triazine-based derivatives, namely 2,4,6-tri (thiophen-2-yl)-1,3,5-triazine (TTT) and 2,4,6-triphenyl-1,3,5-triazine (TPT), as the acceptor units. The resulting CPPs are named ThTx-CPP and PhTx-CPP, respectively. The research findings emphasize the profound impact of minute structural changes in the triazine peripheral groups on the photocatalytic activity of the polymers. Compared to PhTx-CPP, ThTx-CPP exhibits superior light-harvesting capabilities, narrower bandgaps, and improved efficiency in charge separation. Specifically, ThTx-CPP demonstrates outstanding activity and selectivity in both amine coupling and sulfide oxidation reactions, surpassing PhTx-CPP by a significant margin. Furthermore, the catalyst retains its consistent activity even after five cycles of reuse, showcasing its high stability and excellent reusability.