A benzimidazole-based chromogenic anion receptor

✍ Scribed by Ming Yu; Hai Lin; Guanhua Zhao; Huakuan Lin

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 186 KB
• Volume: 20
• Category: Article
• ISSN: 0952-3499
• DOI: 10.1002/jmr.810

✦ Synopsis

Abstract

A benzimidazole‐based anion receptor 1 has been designed and synthesized. The structure of 1 is confirmed through single crystal X‐ray diffraction analysis. Anion‐binding studies carried out using ^1^H NMR and UV–visible revealed that this compound exhibits selective recognition toward F^−^ over other halide anions. The highest selectivity for F^−^ among the halides is attributed mainly to the strongest hydrogen‐bond interaction of the receptor with F^−^; in addition, the higher match in geometry between the receptor and F^−^ also plays a role in the selective recognition of the receptor for F^−^. Receptor 1 (1 × 10^−5^ M) shows dramatic color change from light‐yellow to red in the presence of tetrabutylammonium fluoride (TBAF) (1 × 10^−5^ M). Moreover, F^−^‐induced color changes remain the same even in the presence of a large excess of Cl^−^, Br^−^, I^−^. Copyright © 2006 John Wiley & Sons, Ltd.