Modulating photocatalytic decarbonylative Minisci alkylation through conjugation engineering in pyrene-based hydrogen-bonded organic frameworks

Abstract

The photoredox activity of hydrogen-bonded organic frameworks (HOFs) is remarkable under mild conditions. It is essential to explore the intrinsic correlation between the composition of HOFs and their photocatalytic activity in order to design highly efficient HOFs with outstanding photocatalytic performance. Herein, we utilized pyrene-based molecules featuring diverse π-conjugated structures to fabricate HOFs (HOF-100, HOF-101 and HOF-102) that exhibit similar geometries. Compared to their molecular monomers, HOFs exhibit significantly improved photophysical characteristics and the capability to generate reactive oxygen species (ROS) due to their stronger interlayer arrangement and confinement effect. These pyrene-based HOFs exhibit outstanding photocatalytic performance in decarboxylative Minisci alkylation reactions. Notably, HOF-102 exhibits superior photocatalytic activity compared to HOF-100 and HOF-101 due to its extended π-conjugated system, which alters the internal electric field and reduces the gap energy. This work not only successfully demonstrated the photocatalytic performance of pyrene-based HOFs in the decarbonylative Minisci alkylation process, but also confirmed the influence of the π-conjugation effect on their photocatalytic activity, thus promoting the design and application of HOF-based photocatalysts.