Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India.
Department of Chemistry, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, (SIMATS), Chennai - 602105, Tamil Nadu, India.
Dalton Trans. 2021 Oct 26;50(41):14706-14713. doi: 10.1039/d1dt01803e.
A simple and reliable colorimetric probe ,'-bis-(4-diethylamino-2-hydroxybenzylidene)-1,10-phenanthroline-2,9-carbohydrazide (L) has been synthesised by reacting 4-(diethylamino)salicylaldehyde with 1,10-phenanthroline-2,9-dicarbohydrazide. The sensing ability of L was studied by its interactions with various f-block metal ions and other selected metal ions from s- and d-block by colorimetry, UV-visible spectrophotometry, and smartphone integrated red-green-blue (RGB) model in DMSO : HO (7 : 3, v/v). The pale-yellow colour of L turns to wine-red upon interaction with uranyl ions (UO) and yellow-orange in the presence of Th, Zr, Fe, and Lu ions. Other tested metal ions did not show any colour change of L. This color change offered a simple, quick, and consistent method for the selective and sensitive visual detection of trace levels of UO ions without any need for sophisticated instruments. Sensor L exhibits two absorption bands at 358 and 389 nm due to ligand-to-ligand charge transfer (LLCT). Upon interaction of L with UO and Th ions, absorption bands are exhibited at 480 nm and 422 nm, respectively, due to ligand-to-metal charge transfer (LMCT). The UV-vis spectral studies indicated the formation of a 1 : 2 ligand-to-metal complex between L and UO with an estimated association constant of 1.0 × 10 M. Using L, the concentration of UO can be detected as low as 73 nM and 150 nM by spectrophotometry and RGB methods, respectively, without any interference from other tested ions with an RSD < 5% ( = 3). The binding mechanism was studied by H NMR titration, ESI mass, and FT-IR spectral analysis and was well supported by theoretical results. Overall, sensor L demonstrates promising analytical applicability for the detection of UO ions in a semi-aqueous medium.
一种简单可靠的比色探针，'-双-(4-二乙氨基-2-羟基苯亚甲基)-1,10-菲咯啉-2,9-二羧酸肼（L），是通过将 4-(二乙氨基)水杨醛与 1,10-菲咯啉-2,9-二羧酸肼反应合成的。通过比色法、紫外-可见分光光度法和智能手机集成的红-绿-蓝（RGB）模型，研究了 L 与各种 f 区金属离子以及 s 区和 d 区的其他选定金属离子的相互作用。在 DMSO：HO（7：3，v/v）中，L 的浅黄色变为与铀酰离子（UO）相互作用时的酒红色，而在存在 Th、Zr、Fe 和 Lu 离子时变为黄橙色。其他测试的金属离子没有使 L 发生任何颜色变化。这种颜色变化提供了一种简单、快速和一致的方法，用于选择性和灵敏地检测痕量 UO 离子，而无需复杂的仪器。传感器 L 由于配体-配体电荷转移（LLCT）在 358nm 和 389nm 处显示两个吸收带。当 L 与 UO 和 Th 离子相互作用时，吸收带分别在 480nm 和 422nm 处显示，这是由于配体-金属电荷转移（LMCT）所致。紫外-可见光谱研究表明，L 与 UO 形成了 1:2 的配体-金属络合物，其估计结合常数为 1.0×10 M。使用 L，通过分光光度法和 RGB 方法可以分别检测到 UO 的浓度低至 73 nM 和 150 nM，而其他测试离子没有任何干扰，RSD<5%（n=3）。通过 H NMR 滴定、ESI 质谱和 FT-IR 光谱分析研究了结合机制，并得到了理论结果的很好支持。总体而言，传感器 L 证明了在半水介质中检测 UO 离子的有前途的分析适用性。
