Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India.
Talanta. 2010 Jun 30;82(1):312-8. doi: 10.1016/j.talanta.2010.04.041. Epub 2010 Apr 22.
A new coumarin based hydrazone (receptor 1) synthesized by modifying one of our earlier reported receptor detected fluoride ion selectively through naked eye in aq. DMSO (5:95, v/v). It was also able to detect fluoride through naked eye in a toothpaste sample. The addition of 1 equiv. of fluoride as its tetrabutylammonium salt to the 5 x 10(-5) M aq. DMSO solution of the receptor 1 produced red color while the similar addition of acetate produced faint pink color. The dihydrogenphosphate and a variety of other anions were not able to produce any significant color change with receptor 1 under similar experimental conditions. The corresponding UV-vis measurements showed a bathochromic shifting of 455 nm band of receptor 1 to 514 and 484 nm for fluoride and acetate, respectively. The non-linear fittings of corresponding UV-vis titration data in 1:1 binding equation yielded association constants in 10(5):1 ratio for fluoride and acetate, respectively. The (1)H NMR titrations studies shade further light on their mode of binding with receptor 1. The quantum mechanical calculations through time dependant density functional theory (TD-DFT) using basis set b3lyp/6-311g** supported our experimental findings nicely.
一种新型香豆素基腙（受体 1）通过修饰我们之前报道过的一种受体合成，可在 aq.DMSO（5:95，v/v）中通过肉眼选择性检测氟离子。它还能够通过肉眼在牙膏样品中检测到氟离子。向 5 x 10(-5) M 的受体 1 的 aq.DMSO 溶液中加入 1 当量的四丁基铵盐作为氟离子，会产生红色，而类似量的醋酸盐则会产生微弱的粉红色。在类似的实验条件下，二氢磷酸盐和各种其他阴离子都不能与受体 1 产生任何明显的颜色变化。相应的紫外可见测量显示，受体 1 的 455nm 带发生了红移，分别为 514nm 和 484nm，用于氟离子和醋酸盐。根据 1:1 结合方程的相应紫外可见滴定数据的非线性拟合，分别得到了氟离子和醋酸盐的结合常数为 10(5)：1 的比例。（1）H NMR 滴定研究进一步阐明了它们与受体 1 的结合方式。通过使用基组 b3lyp/6-311g**的时间相关密度泛函理论（TD-DFT）进行量子力学计算，很好地支持了我们的实验结果。
