Symmetry-dependent photocatalysis of conjugated microporous polymers based on pyrene for oxygenation of sulfides with O2

To date, conjugated microporous polymers (CMPs) have been developed into multifaceted photocatalysts. Here, two CMPs based on pyrene with the linkages of thiazolo[5,4-d]thiazole (TzTz) are prepared for visible light photocatalysis. The dimension of the molecular building block’s symmetry on the property and activity of CMPs is systematically investigated. Py(4)-TzTz-CMP with a pyrene building block of D2h symmetry gives rise to better optoelectronic property than Py(2)-TzTz-CMP with a pyrene building block of C2 symmetry. Therefore, Py(4)-TzTz-CMP photocatalyst is endowed with superior conversions for the green light-promoted oxygenation of sulfides with O2. Intriguingly, mechanistic explorations disclose that both superoxide and singlet oxygen are responsible for the production of the target sulfoxides. This work gives insight into the rational design of highly active CMP photocatalysts for selective chemical transformations.