A multi writable thiophene-based selective and reversible chromogenic fluoride probe with dual -NH functionality

作者：Vishwakarma Siddharth; Kumar Ajit; Pandey Abha; Upadhyay K K^*

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2017, 170: 191-197.

DOI：10.1016/j.saa.2016.07.021

• bis-Schiff base
• Fluoride
• Chromogenic sensor
• Density functional theory
• Logic gate

A chromogenic fluoride probe bearing bis imine groups having dual -NH functionality (BSB) has been designed, synthesised and structurally characterized by its single crystal X-ray diffraction studies. The BSB could visually and spectroscopically recognise F- with high selectivity over other anions by exhibiting intense chromogenic response (from colourless to red) for F- in acetonitrile solution. The UV-visible titration and H-1 NMR titration experiments indicated that the observed changes occur via a combined process including hydrogen bonding and deprotonation between the BSB and F-. Moreover theoretical calculations at the Density Functional Theory (DFT) level shed further light upon probe design strategy and the nature of interactions between BSB and F-. The limit of detection and binding constant of BSB towards F- were found to be 6.9 x 10(-7) M and 1.42 +/- 0.069 x 10(8) M-2 respectively. Finally, by using F- and H+ as chemical inputs and the absorbance as output, a IN-HIBIT logic gate was constructed, which exhibits "Multi-write" ability without obvious degradation in its optical output.

• 出版日期2017-1-5