A Novel Conjugated Polymer Consists of Benzimidazole and Benzothiadiazole: Synthesis,Photophysics Properties,and Sensing Properties for Pd2+

A conjugated polymer PPBIBTE based on benzimidazole and benzothiadiazole was synthesized through palladium-catalyzed sonogashira cross-coupling reaction. The chemical structures of the monomers and the polymer were indicated by ¹H NMR, and investigation of photophysics properties and sensing optical properties for metal ions were observed by ultraviolet–visible and photoluminescence spectroscopy. PPBIBTE showed remarkable selectivity for Pd²⁺ by “turn-off” fluorescence sensing progress. In addition, the Stern–Volmer and Benesi-Hildebrand plots were used to reveal the interaction between the polymer and Pd²⁺, while job's method was applied to calculate the determination of stoichiometry. The results demonstrate that PPBIBTE can utilize static quenching for Pd²⁺ by forming a 1:1 complex. And it is a potential sensing material as fluorescence chemosensor for Pd²⁺ with high selectivity and sensitivity. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 831-842