Design and Development of Robust Fluorescent COFs

Abstract

The incorporation of different fluorescent entities in an organic framework can be effective in generating white light emitting polymeric materials, and Covalent Organic Framework (COF) is one such compound which can be used to achieve the same. Here, we have synthesized six different Schiff-base based model compound of COFs to gain insight into steady-state emission with changing amine and aldehyde groups. After studying the model compounds, in anticipation of white light emission, we synthesized three similar Schiff-base based COFs, with the aldehyde and pyridine rich amines responsible for emission in the green and red region of the visible spectra and anthracene amine responsible for blue emission. Although we expect the COF to be a solid-state white light emitter, it turns out to show poor fluorescence because of particle aggregation-induced self-quenching. Addressing the self-quenching remains a big problem without which single-source white light-emitting materials such as COFs cannot make a windfall.