An Upgraded "Two-in-One" Strategy toward Highly Crystalline Covalent Organic Frameworks.

A highly crystalline bicarbazole-based covalent organic framework (BCzP-COF) was synthesized via an upgraded "two-in-one" strategy by the self-polycondensation of A2 B2 monomer with two neopentyl acetal and two amine groups. Such a strategy is propitious to afford higher crystallinity, larger special surface areas and better morphology than that of using unprotected monomer with free aldehydes and amines. Additionally, the off-white powder of BCzP-COF could serve as acidichromism sensor with a significant color change. Intriguingly, the conductivity of the protonated BCzP-COF can improve by six orders of magnitude compared to that of the pristine samples. This work has the potential to lead to bicarbazole-functional materials for chemosensors and electronic devices.