Herein, for the first time, we have reported a copper(II) bis(terpyridine) complex solution for instant ‘naked eye’ chromo-luminescent selective detection of fluoride ions in an acetonitrile medium at micromolar concentration. The copper complex [Cu(II) (L)₂] (NO₃)₂ [where L = 4′-(4-N,N′-dimethylaminophenyl)-2,2′:6′,2′′-terpyridine] was characterized by mass spectroscopy and the terpyridine ligand by ¹H NMR spectroscopy. The complex solution selectively discriminates F⁻ ions from other anions such as AcO⁻, Br⁻, Cl⁻, CN⁻, H₂PO₄⁻, HSO₄⁻, and I⁻ in acetonitrile media via exceptional optical changes. The optical changes were evaluated by UV-visible and fluorescence techniques. Studies on the binding characteristics of the copper complex solution with fluoride ions revealed a displacement of copper ions from the complex solution as CuF₂ resulting in the significant optical changes. Furthermore, displacement of Cu(II) from the complex was established by means of mass spectroscopy in the presence of 20 equivalents of fluoride ions. The limit of detection (LOD) was found to be 5.07 μM which is within the permissible range of fluoride ions in drinking water set by the World Health Organization (WHO).

中文翻译：

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铜（ii）双（三吡啶）配合物通过置换法对荧光离子进行色光选择检测†

在此，我们首次报道了铜（II）双（叔吡啶）络合物溶液，用于在微摩尔浓度的乙腈介质中对氟离子进行即时的“裸眼”层析发光选择性检测。铜络合物[Cu（II）（L）₂ ]（NO ₃）₂ [其中L = 4'-（4- N，N'-二甲基氨基苯基）-2,2'：6'，2''-叔吡啶]通过质谱分析和通过¹ H NMR光谱分析联吡啶配体。该络合物溶液选择性地判别˚F ^-离子从其它阴离子如ACO ^- ，溴^- ，氯^-，CN^-，H ₂ PO ₄ ^-，HSO ₄ ^-和I ^-在乙腈介质经由特殊的光学变化。通过紫外可见和荧光技术评估光学变化。对铜络合物溶液与氟离子的结合特性的研究表明，铜离子作为CuF ₂从络合物溶液中置换出来，导致了显着的光学变化。此外，Cu（ II在20当量的氟离子存在下，通过质谱法从络合物中确定了该化合物。发现的检出限（LOD）为5.07μM，在世界卫生组织（WHO）设定的饮用水中氟离子的允许范围内。