Fluorescence porous organic polymers synthesized via transition metal-free thiol-yne click chemistry for fluorescence sensing bismuth triiodide

Bismuth tri-iodide (BiI3) is commonly determined by spectrophotometric method and atomic absorption spectrometry (AAS) methods, which requires adding the appropriate color developer or re-extraction, and the operation is cumbersome. Herein, we developed the method of detecting BiI3 with fluorescence spectroscopy for the first time. In this contribution, two novel thiol-linked POPs have been successfully synthesized by thioalkynes click polymerization. The chemical structures of the as-prepared thiol-linked POPs were characterized by FT-IR, ss 13 C NMR, UV-vis absorption spectra, and elemental analysis. The as-prepared thiol-linked POPs emit strong fluorescence in 1,4-dioxane (DOX) and could be used for selectively detection of BiI3 with the high quenching constants of 4.04 x 104 and 4.35 x 104 L mol-1 , and with the low limits of detection (LODs) of 7.43 x 10-10 and 6.90 x 10-10 mol L-1 , respectively. The study of UV-vis absorption spectroscopy has proved that the specific fluorescence quenching process of the thiol-linked POPs to BiI3 is an absorption competition quenching mechanism.