Novel 2,3-bis(1H-pyrrol-2-yl)quinoxaline-functionalized hydrazones were prepared and characterized as new chemosensors for copper(II) ion. The binding properties of the compounds 4, 5, 6 and 7 for cations were examined by UV–vis, fluorescence spectroscopy, and linear sweep voltammetric experiments (LSV). The results indicate that a 1:1 stoichiometric complex is formed between compound 4 (or 5, 6, 7) and copper(II) ion, and the association constant is 1.3 × 105 M−1 for 4, 2.1 × 106 M−1 for 5, 4.1 × 105 M−1 for 6 and 8.0 × 105 M−1 for 7, respectively. The recognition mechanism between compound 4 (or 5, 6, 7) and metal ion was discussed based on their electrochemical properties, absorbance changes, and the fluorescence quenching effect when they interact with each other. Control experiments revealed that compound 4 (or 5, 6, 7) has a highly selective response to copper (II) ion.

中文翻译：

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二吡咯基喹喔啉桥连腙：一类新的铜（II）化学传感器

制备了新型 2,3-双 (1H-吡咯-2-基) 喹喔啉官能化腙，并将其表征为铜 (​​II) 离子的新型化学传感器。化合物 4、5、6 和 7 对阳离子的结合特性通过紫外-可见光、荧光光谱和线性扫描伏安实验 (LSV) 进行了检测。结果表明，化合物4(或5、6、7)与铜(II)离子形成1:1的化学计量配合物，4、2.1×106 M-1的缔合常数为1.3×105 M-1分别为 5、4.1 × 105 M−1 和 6 和 8.0 × 105 M−1 7。从化合物4（或5、6、7）与金属离子的电化学性质、吸光度变化以及相互作用时的荧光猝灭效应等方面讨论了化合物4（或5、6、7）与金属离子的识别机制。对照实验表明，化合物 4（或 5、6、