In 2018,Dyes and Pigments included an article by Yan, Zhengquan; Wei, Gang; Guang, Shanyi; Xu, Manman; Ren, Xia; Wu, Rongliang; Zhao, Gang; Ke, Fuyou; Xu, Hongyao. Formula: C6H7Br2N. The article was titled 《A multidentate ligand chromophore with rhodamine-triazole-pyridine units and its acting mechanism for dual-mode visual sensing trace Sn2+》. The information in the text is summarized as follows:
A multidentate ligand chromophore, combining rhodamine, triazole, and pyridine units, was identified and developed for the 1st time. Using triazole and pyridine rings as coordinating functional recognition groups, it was expected to selectively recognize Sn2+ to form some stable 5-member or 6-member rings with nitrogen and oxygen atoms. Under the optimized conditions, the ligand chromophore could selectively react with trace Sn2+ in CH3CN/H2O (99/1, volume/volume), accompanying with obvious changes in fluorescent spectrum, UV-visible spectrum and visual color. For fluorescent anal., a turn-on fluorescence at 587 nm was found and increased linearly at 1.2-6.2 × 10-7 mol L-1 Sn2+ from colorless to orange. For UV-visible one, a new absorption peak at 560 nm emerged with a linear range of 2.0-11.0 × 10-7 mol L-1 Sn2+ from colorless to pink. The action mechanism between the ligand chromophore and Sn2+ was confirmed basing on UV-visible titration, 1H NMR titration, Job’s plot, binding constants and theor. calculation In addition to this study using 2-(Bromomethyl)pyridine hydrobromide, there are many other studies that have used 2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8Formula: C6H7Br2N) was used in this study.
2-(Bromomethyl)pyridine hydrobromide(cas: 31106-82-8) belongs to pyridine. When pyridine is adsorbed on oxide surfaces or in porous materials, the following species are commonly observed: (i) pyridine coordinated to Lewis acid sites, (ii) pyridine H-bonded to weakly acidic hydroxyls, and (iii) protonated pyridine. At high coverage, physisorbed pyridine and protonated dimers can also be observed.Formula: C6H7Br2N