Highly selective fluorescent sensing of Cu(2+) ion by an arylisoxazole modified calix[4]arene

Abstract

A novel fluorescent chemosensor 1 with two anthraceneisoxazolymethyl groups at the lower rim of calix[4]arene has been synthesized, which revealed a dual emission (monomer and excimer) when excited at 375 nm. This chemosensor displayed a selective fluorescence quenching only with Cu(2+) ion over all other metal ions examined. When Cu(2+) ion was bound to 1, the fluorescence intensities of both monomer and excimer were quenched. Furthermore, the association constant for the 1:1 complex of 1.Cu(2+) was determined to be (1.58 +/- 0.03) x 10(4) M(-1). (c) 2008 Elsevier Ltd. All rights reserved.