A Cu(II) based sensor (1) prepared by the complexation between (quinolin-8-ylamino)-acetic acid hydrazide (L²) and Cu²⁺ ions has been developed for a highly sensitive and selective recognition of HNO and S²⁻ over other biologically abundant anions with prominent enhancement in absorption and emission intensities. The sensor (1) shows weak fluorescence due to ET (electron transfer) but upon addition of HNO and S²⁻ a large enhancement in the fluorescence intensity (F.I.) was observed over other possible competitive anions on the basis of reduction of Cu(II) to Cu(I) and formation of CuS, respectively. The 1 : 1 complexation was characterized by mass spectrometry (MS), elemental analysis and Job's plot. The corresponding K_f value was evaluated to be (4.934 ± 0.05) × 10⁴ M⁻¹ for Cu²⁺ from UV-Vis absorption titration. Quantum yields of L² and [Cu-L² + S²⁻] and [Cu-L² + HNO] complexes in acetonitrile (CH₃CN) are found to be 0.107, 0.09 and 0.07, respectively, using quinine sulphate as the standard.

中文翻译：

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使用基于Cu（ii）配合物的探针 对HNO和S ^2-离子的双响应荧光传感器，并辅以详细的DFT研究†

通过（喹啉-8-基氨基）-乙酸酰肼（L ²）和Cu ²⁺离子的络合制备的基于Cu（II）的传感器（1）已被开发用于高度敏感和选择性地识别HNO和S ^{2 −}超过其他生物丰富的阴离子，吸收和发射强度显着提高。传感器（1）由于ET（电子转移）而显示出弱荧光，但是在添加HNO和S ^2-的情况下，由于铜（II）的还原，与其他可能的竞争性阴离子相比，荧光强度（FI）大大提高。）到Cu（I）和CuS的形成。1：1络合物通过质谱（MS），元素分析和Job's图表征。通过UV-Vis吸收滴定，对于Cu ²⁺，相应的K _f值被评估为（4.934±0.05）×10 ⁴ M ^-1。使用硫酸奎宁作为溶剂，发现乙腈（CH ₃ CN）中L ²和[ Cu-L ² + S ²⁻ ]和[ Cu-L ² + HNO]配合物的量子产率分别为0.107、0.09和0.07。标准。