A novel microporous phosphazene-triazinyl based covalent organic framework: Preparation, characterization and fluorescence properties

Covalent organic frameworks(COFs) attracted more and more attention due to the unique advantages, such as flexible topological connectivity, regular periodic pore structures, excellent stability and tunable functionality. Recently, several covalent organic frameworks(COFs) were developed for fluorescence detection of metal ions, explosives, VOCs, and so on. In this work, a novel fluorescent COFs(HM-COF) based on phosphazene and triazinyl was prepared by polymerization of hexachlorocyclo-triphosphazene(HCCP) and melamine(MA) successfully. The BET surface area and pore size of HM-COF were calculated as 305.7 m2 g-1 and 12.6 Å, respectively. HM-COF can emit strong fluorescence under ultraviolet lamp. An obvious fluorescent quenching of HM-COF was observed by adding Fe3+ aqueous solution, which demonstrated that HM-COF can act as a good fluorescent sensor for detecting Fe3+ cations. Furthermore, HM-COF can also be used for the qualitative detection of nitro aromatic compounds.