Emissive organogel mediated construction of a flexible covalent organic polymer for the separation of aniline for water purification

Abstract

A flexible covalent organic polymer (COP) has been successfully synthesized via dynamic covalent gel (DCG) formation through an imine condensation reaction between 6-hydrazinonicotinic hydrazide hydrate and benzene-1,3,5-tricarboxaldehyde within 7 min under ambient conditions. An emissive organogel mediated protocol has been developed for the construction of an amorphous polymer (COP), selectively in N,N-dimethyl acetamide (DMA). Interestingly, two non-emissive building block units without large π-conjugated structures have been engaged for the construction of green emissive COP-gel. The green emission of COP-gel is generated by the intermolecular H-bonding assisted aggregation induced emission phenomenon. The dried COP efficiently adsorbs aniline molecules into its cavities and separates them from binary mixtures of aniline/nitrobenzene and aniline/water, respectively.