Mechanosynthesis of 1,2,4-triazine-appended polyvinyl chloride (PVC) and studies of its fluorescence “ <i>turn-off</i> ” response to Fe ³⁺

Iron plays crucial role in such important biochemical processes in the human body as the respiratory function. Both deficiency and excess of Fe3+/Fe2+ could induce serious diseases, including heart failure and diabetes. Additionally, iron is among essential micronutrient elements for the living organisms in the environment, as it is involved in plant metabolism, electron transport of photosynthesis and respiration, chlorophyll synthesis, nitrate reduction, and detoxification of reactive oxygen species. The methods and materials for the detection of Fe3+ /Fe2+ are of high demand. In this manuscript we wish to report a mechanochemical approach for the post-modification/functionalization of PVC with 3-(pyridyl-2)-1,2,4-triazine moieties to obtain a polymeric material for the visual detection of Fe3+/ Fe2+. The obtained polymer was characterized by means of 1H NMR- and IR-spectroscopy, as well as gel-penetration chromatography (GPC). Colorimetric and fluorescence “turn-off” response towards Fe2+ and Fe3+ in solution was investigated, and a Stern-Volmer constant as high as 0.1-0.3∙1o6 M–1 was observed for Fe3+.