Optical absorptions of benzotrithiophene-based covalent organic frameworks evolving with amine-building blocks

Optical absorptions of benzotrithiophene-based covalent organic frameworks (COF) are investigated through rationally tuning the sizes and nitrogen introductions of the amine-building blocks. Blue shifts of the absorption edges are observed within the visible region, whether increasing the sizes of the amines or introducing nitrogen atoms into them. This study has some guiding significance for the design and synthesis of COFs or other reticular materials toward optical applications.