A Highly Selective Fluorescent Chemosensor for H2PO4– Based on a Calix[4]arene Tetraamide Derivative

✍ Scribed by Qi-Yin Chen; Chuan-Feng Chen

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 145 KB
• Volume: 2005
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.200400832

✦ Synopsis

Abstract

A new neutral fluorescent chemosensor 5 based on a calix[4]arene tetraamide derivative has been synthesized. It exhibits high selectivity for H~2~PO~4~^–^ over a wide range of anions, and the selectivity for H~2~PO~4~^–^ is more than 2700‐fold higher than for F^–^. In acetonitrile, the fluorescence intensity of 5 is efficiently enhanced about 130 % [(I – I~0~)/I~0~] upon the addition of 5 equiv. of H~2~PO~4~^–^. From the fluorescence titration experiments, the association constant for 5/H~2~PO~4~^–^ (1:2) was calculated to be 5.48 × 10^9^ M^–2^. Furthermore, the ^1^H NMR spectral and X‐ray crystal studies suggested that multiple hydrogen‐bonding interactions occur between 5 and H~2~PO~4~^–^.