The Structural Regulation of Photosensitive Unit and Conjugation in COFs for Efficient Photocatalytic H Evolution.

The photosensitive unit and conjugation play a significant role in   photocatalytic performance of covalent organic frameworks (COFs). In this work, a series of COFs that introduced the phenyl phenanthridine as photosensitive unit with different planarity of linkages were synthesized and the common regulation between them for photocatalysis hydrogen evolution reaction (HER) was also studied. The results indicate that DHTB-PPD, with 2/3 planarity linkages (β-ketoenamine/imine is 2/3) and the phenyl phenanthridine as building blocks, shows the narrowest bandgap and the strongest charge separation efficiency.

Covalent Organic Frameworks Doped with Different Ratios of OMe/OH as Fluorescent and Colorimetric Sensors.

Improving the luminescence properties of covalent organic frameworks (COFs) has always been an important issue. Here, a series of COFs (([OMe] -TzDa (TzDa is composed only by monomerics Tz and Da, OMe represents the incorporation of monomeric Dm)) with different ratios of OMe and OH were designed and synthesized. The photochemical behavior of [OMe] -TzDa changed significantly due to the synergistic effect of aggregation induced emission (AIE), intramolecular charge transfer (ICT), and excited-state intramolecular proton transfer (ESIPT) effects.