Enhanced Photocatalytic Efficiency and Structural Stability of Uranyl-Organic Coordination Polymers via the Semirigid Ligand

This is the authors' abstract. We don't add key points for this paper.

Uranyl-organic coordination polymers (UOCPs) have been demonstrated to exhibit photocatalytic activity, but highly stable UOCPs with excellent photocatalytic efficiency are rare. Herein, we present a series of UOCPs built by a semirigid benzimidazole-derived carboxyl ligand. By rationally designing the rigid and flexible sections of the ligand, we have obtained UO 2 (HBDA)(OH)·H 2 O ( UOCP-SU-1 ), UO 2 (HBDA)(H 2 BDA)(NO 3 )·H 2 O ( UOCP-SU-2 ), and UO 2 (HBDA) 2 ( UOCP-SU-3 ) with multiple spatial configurations under different conditions ([H 3 BDA]Cl = 1,3-bis(4-carboxybenzyl)-1,3-dihydro-2 H -benzo[ d ]imidazol-2-iminium chloride). The structural and photoelectrochemical properties of these UOCPs were systematically investigated, and the relationship between coordination structure and the photocatalytic performance for photooxidation of benzylamine to N -benzylenzoimide has been well established. The UOCP-SU-1 with bridged oxygen ligands in the coordination structure exhibits the best visible-light response and chemical conformational stability activity. Importantly, the UOCP-SU-1 can maintain its original crystal structures after 10 cycles of catalysis. This work provides a novel strategy for developing efficient uranyl-based photocatalysts for organic reactions.