Pore wall fluorescence labeling of covalent organic frameworks

Abstract

A novel covalent organic framework (COF) based on terphenyldiboronic acid exhibiting open pores of about 4.1 nm is presented. The newly synthesized COF features accessible hydroxyl groups at the inner and outer pore walls. These functional groups serve as anchor sites for a fluorescence label installed through a post-synthetic modification approach. By forming o-thiocarbamate bonds, fluorescein molecules were immobilized on the inner and outer surfaces of the pore system, respectively. This grafting reaction was also extended to a second COF (COF-5) and to other grafted moieties.