The synthesis of conjugated microporous polymers via Friedel–Crafts reaction of 2,4,6-trichloro-1,3,5-triazine with thienyl derivatives for fluorescence sensing to 2,4-dinitrophenol and capturing iodine

Abstract

Two nitrogen-rich conjugated microporous polymers (TEDOT and TBTh) were successfully synthesized through the Friedel–Crafts reaction with methiononysulfonic acid as the catalyst. We introduced the thiophene units into these two conjugated microporous polymers (CMPs), and the rigid conjugated frameworks of polythiophene facilitate the formation of porous polymers with high stability and perpetual porosity. The yields of TEDOT and TBTh were 80.83% and 75.83%, respectively. Both of them have relatively good thermal stability. Because hybrid atoms (nitrogen or sulfur) exist in the structures, the two CMPs are electron-rich, enhancing the interaction between CMP networks and analytes. Thus these two CMPs have the capacity of fluorescence detecting 2,4-dinitrophenol (DNP) with quite good sensitivities. The values of Ksv are 1.88 ​× ​105 ​L ​mol−1 and 2.18 ​× ​104 ​L ​mol−1, and the LODs are 1.38 ​× ​10−10 ​mol ​L−1 and 1.59 ​× ​10−13 ​mol ​L−1. Besides, the two CMPs show good iodine absorption and desorption properties in both vapor and solution.