A Visible Light Responsive Smart Covalent Organic Framework with a Bridged Azobenzene Backbone.

Condensation of 3,3′‐diamino‐2,2′‐ethylene‐bridged azobenzene with 1,2,4,5‐tetrakis‐(4‐formylphenyl) benzene produces a visible light responsive porous 2D covalent organic framework, COF‐bAzo‐TFPB, with a large surface area, good crystallinity, and thermal and chemical stability. The results demonstrate that the elaborated designed linker can make azo unit on the COF‐bAzo‐TFPB skeleton undergo reversible photoisomerization. This work expands the application scope of covalent organic frameworks in photo‐controlled release, uptake of guest molecules, dynamic photoswitching, and UV‐sensitive functions. [ABSTRACT FROM AUTHOR]