Highly selective detection of fluoride based on 2,2-diferrocenylpropane benzimidazolium borate-ester salt

• Published in: Tetrahedron letters 2016-03, Vol.57 (11), p.1250-1255
• Main Authors: Su, Zhi-Ming, Yan, Xi-Quan, Liang, Chao-Li, Lin, Cai-Xia, Xie, Li-Li, Yuan, Yao-Feng
• Format: Article
• Language: English
• Subjects: 1H NMR titration; Absorption spectra; Anion receptor; Anions; Binding; Bonding; Electrochemistry; Fluoride detection; Nuclear magnetic resonance; Receptors; Reduction; Selectivity; UV–vis
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2016.02.019

[Display omitted] A new anion receptor that utilized boron–fluoride interaction and (CH)+⋯F−-type ionic hydrogen bonding in the binding of F ions had been synthesized and characterized by IR, MS, HRMS, 11B, 1H, and 13C NMR spectra. The signaling process was confirmed by UV–vis, electrochemistry measurements as well as 1H, 19F, and 11B NMR spectroscopy. Among the tested anions: F−, Cl−, Br−, OAc−, H2PO4−, HSO4−, only F− induced a remarkable red-shift (29nm) in the absorption spectrum which was concomitant with a color change from pink to faint yellow. This receptor provided a new approach for naked-eyed detection of F− and the detection limit was calculated to be 1.26μM. Besides, Cyclic Voltammetry (CV) showed that the receptor had unique selectivities for F− with a remarkable phenomenon in merging of the two reduction peaks in response to the increment addition of the anions. 1H, 19F, and 11B NMR titrations demonstrated that the receptor showed affinity and high selectivity for F− and provided the evidence of interaction between the receptor and F−.