Bachelor Degree Program in Marine Biotechnology, National Taiwan Ocean University, Keelung 202, Taiwan.
Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan.
Analyst. 2022 Nov 7;147(22):5105-5112. doi: 10.1039/d2an01201d.
Calix[4]arene 1, with two lower-rim isoxazolylchloroanthracene groups, is shown to be not only a chromogenic but also a fluorogenic chemodosimeter for the selective sensing of Cu. The binding properties of ligand 1 and control compounds 2 and 3 toward metal ions in CHCN/CHCl (v/v, 1 : 1) were investigated by UV-vis and fluorescence spectroscopy. The results showed that only ligand 1 was highly selective for Cu ions. When complexed with Cu, ligand 1 displayed a new absorption band around 435 nm and the color of the solution changed from colorless to yellow. Furthermore, the fluorescence of ligand 1 was severely quenched by Cu and the limit of detection (LOD) was determined to be 1.674 μM. Therefore, compound 1 is not only a chromogenic but also a fluorogenic sensor for the detection of Cu ions over other metal ions examined. When complexed with ligand 1, Cu was reduced to Cu by the free phenolic-OH of ligand 1 and concurrently the phenol was oxidized by Cu to quinones. The H NMR, EPR, and FTIR spectra provided evidence for the redox behavior of ligand 1 with Cu. The isolation of calix[4]diquinone 8 and Cu(CHCN)ClO from the reaction of ligand 1 with Cu(ClO) confirmed their redox reaction.
杯[4]芳烃 1，带有两个下边缘异恶唑基氯蒽，不仅是显色剂，也是荧光化学传感器，可选择性检测 Cu。通过紫外可见光谱和荧光光谱研究了配体 1 和对照化合物 2 和 3 在 CHCN/CHCl（体积比 1:1）中对金属离子的结合特性。结果表明，只有配体 1 对 Cu 离子具有高度选择性。当与 Cu 络合时，配体 1 在大约 435nm 处显示出一个新的吸收带，溶液的颜色从无色变为黄色。此外，配体 1 的荧光被 Cu 严重猝灭，检测限（LOD）确定为 1.674μM。因此，化合物 1 不仅是一种显色传感器，也是一种用于检测 Cu 离子的荧光传感器，可检测到其他检测的金属离子。当与配体 1 络合时，Cu 被配体 1 中的游离酚-OH 还原为 Cu，同时酚被 Cu 氧化为醌。H NMR、EPR 和 FTIR 光谱为配体 1 与 Cu 的氧化还原行为提供了证据。从配体 1 与 Cu(ClO)的反应中分离出杯[4]二醌 8 和 Cu(CHCN)ClO 证实了它们的氧化还原反应。
