Abstract

A new set of receptors based on a dimethylxanthene skeleton has been synthesized. Owing to its suitable oxyanion hole structure, these receptors can associate with carboxylic acids. The combination of this skeleton with a fluorescent unit such as dansyl allows the detection of small amounts of carboxylic acids by making use of fluorescent techniques, such that the response of daxabe depends on the nature of the guest. Anions such as halogenides are also suitable guests for daxabe and can be associated. This receptor also afforded good results in the extraction of zwitterionic amino acids from the aqueous to the organic layer in the presence of 18-crown-6 ether. ((c) Wiley-VCH Verlag GmbH Co. KGaA, 69451 Weinheim, Germany, 2009)