Abstract:
This review covers few examples of anion complexation chemistry, with a special focus on
urea/thiourea-based receptors and Zn(II)-dipicolyl amine-based receptors. This article specially focuses on
structural aspects of the receptors and the anions for obtaining the desire specificity along with an efficient
receptor–anion interaction. Two types of receptors have been described in this brief account; first one being
the strong hydrogen bond donor urea/thiourea derivatives, which binds the anionic analytes through hydrogen bonded interactions; while, the second type of receptors are coordination complexes, where the coordination of the anion to the metal centre. In both the cases the anion binding modulate the energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and thereby the spectroscopic response. Appropriate choice of the signalling unit may allow probing the anion binding phenomena through visual detection.