Anion complexation and sensing using modified urea and thiourea-based receptors.

This critical review highlights recent advances in the structurally modified (thio)urea-based receptors for anion complexation and sensing. Modifications of the (thio)urea structure are aimed at a better anion binding in terms of higher binding constant, anion selectivity and feasibility. Major (thio)urea receptors are reviewed as N-alkyl, N-aryl and N-amido/N-amino (thio)ureas. Hints for designing (thio)urea-based receptors for anions are discussed (102 references).