Photocatalytically Active Conjugated Porous Polymers via Click Chemistry for Heterogeneous Dehydrogenation of Hydrazo Aromatics
Chaoyang Song, Biao Liu, Junqi Nie, Chao Ma, Cuifen Lu, Feiyi Wang, Guichun Yang, Zuxing Chen
Abstract
Aromatic azo compounds are an important class of raw materials and are widely used in chemical industries. However, current synthetic methods have many disadvantages, which limit their practical utility. Here, we report a facile approach to prepare 1,2,3-triazole-contained conjugated porous polymers (CPPs; Ta-Ths) through click reaction of azide and terminal alkynes and employ the click-based CPPs for the first time as photocatalysts. By changing the structure of alkyne monomer, Ta-Ths with distinct optoelectronic properties are obtained to effectively catalyze the visible light-driven oxidative dehydrogenation of hydrazo aromatics. Moreover, the Ta-Ths show much higher catalytic activity as compared with previous homogeneous photocatalysts. The CPP that possesses better charge transfer efficiency and lower charge recombination rate was found to have more catalytic activity than the others. In addition, this protocol was demonstrated on a gram scale without any erosion of yield. Furthermore, the polymer photocatalyst has shown reliable recyclability with no significant loss in its catalytic activity.