Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Jul 5;255:119718. doi: 10.1016/j.saa.2021.119718. Epub 2021 Mar 19.
In this study, three new compounds 6-substituted-3-acetylcoumarin 4-(2'-isocamphanyl)thiosemicarbazones (3a, 3b, and 3c) were facilely synthesized and employed as colorimetric chemosensors for fluoride ions. The recognition behaviors of receptors 3a, 3b, and 3c toward F were investigated by using UV-vis absorption spectroscopy. Among them, the receptor 3c displayed more superior sensitivity and rapid response time toward F with a swift naked-eye color change from colorless to purple, and its detection limit was as low as 6.3 × 10 M, and the binding constant was calculated to be 2.58 × 10 M. Furthermore, the interaction mechanism between the receptor 3c and F was studied by H NMR, HRMS, and density functional theory (DFT) studies, suggesting that initial formation of a hydrogen-bonded host-guest complex and the subsequent deprotonation of receptor 3c upon the addition of excess F, which was responsible for the remarkable changes in the absorption spectra of 3c. Besides, a combinatorial logic circuit of IMPLICATION and INHIBITION gates at the molecular level was fabricated using the reversibility of receptor 3c toward F and Mg. Finally, the test strips coated with receptor 3c revealed a good sensitivity for F in an aqueous medium. Apart from that, the excellent performance of receptor 3c for detecting F was reconfirmed by grinding them with KBr powder.
在这项研究中，我们简便地合成了三种新的化合物 6-取代-3-乙酰香豆素 4-(2'-异坎烯基)硫代半缩酮（3a、3b 和 3c），并将其用作氟离子的比色化学传感器。通过使用紫外-可见吸收光谱研究了受体 3a、3b 和 3c 对 F 的识别行为。其中，受体 3c 对 F 具有更优异的灵敏度和快速响应时间，能够迅速实现从无色到紫色的裸眼颜色变化，其检测限低至 6.3×10 M，结合常数计算为 2.58×10 M。此外，通过 1 H NMR、高分辨率质谱（HRMS）和密度泛函理论（DFT）研究，研究了受体 3c 与 F 之间的相互作用机制，表明 F 的加入首先形成了氢键的主客体配合物，随后受体 3c 去质子化，这是 3c 吸收光谱发生显著变化的原因。此外，还使用受体 3c 对 F 和 Mg 的可逆性在分子水平上构建了 IMPLICATION 和 INHIBITION 门的组合逻辑电路。最后，用受体 3c 涂覆的测试条在水介质中对 F 表现出良好的灵敏度。除此之外，通过将它们与 KBr 粉末研磨，进一步证实了受体 3c 对 F 检测的优异性能。
