Preparation of a metal-ligand fluorescent chemosensor and enantioselective recognition of carboxylate anions in aqueous solution

摘要

Two chiral fluorescent chemosensors 1 and 2 were synthesized, and the structure characterized by IR, H-1 NMR, C-13 NMR, MS spectra and elemental analysis. Their recognition ability was studied in aqueous solution (Tris-HCl buffer pH 7.4, MeOH/H2O = 1: 1) through fluorescence spectra. Receptors 1 and 2 showed a good binding ability to the copper ion. The host 1-Cu2+ complex showed a chiral recognition ability to mandelate anions with a preferable binding to L-mandelate than D-mandelate anions. The host 1-Cu2+ complex and L- or D-mandelate anions formed 1:1 stoichiometric complex. The binding constant for L-mandelate is 576 M-1, whereas that for D-mandelate is only 38 M-1, which can be distinguished by the different change of fluorescence intensity. (C) 2008 Elsevier Ltd. All rights reserved.