Crystal transformation of metal–organic frameworks to boost visible-light photocatalysis via amine adsorption

Abstract

Herein, we report the synthesis of a novel metal–organic framework (MOF) photocatalyst via the postsynthetic pillaring method. The crystal transformation of photoactive 2D MOF to microporous 3D MOF was achieved, and the resultant MOF exhibited enhanced amine adsorption due to intrapore host–guest interaction. The oxidation of amine by the MOF was then utilized smartly to trigger perfluoroalkylation that can hardly be achieved by a MOF photocatalyst. The photocatalytic reaction exhibited excellent yield, high efficiency, and general applicability in the preparation of fluorine-containing functional chemicals. Mechanism studies show that the reaction was triggered by the photoinduced oxidation of amine by the MOF, which generated aminoalkyl radicals that are conducive to substrate activation. This study presents a goal-directed synthesis of a porous photocatalyst via the postsynthetic transformation of MOFs and provides a promising protocol based on host–guest interaction to achieve highly efficient photocatalysis.