The field of anion supramolecular chemistry has expanded enormously during the past few decades, inspired in large part by the realization of the many fundamental roles negatively charged species play in a range of chemical, biological, medical and environmental processes. However, the field of anion receptor chemistry is relatively underdeveloped compared with cation receptor chemistry.

This is because the binding of anions is inherently more difficult than for cations. Although many research groups are working in the design of new anion receptors, their success in the developing of receptor in water is still very low, due to the tools used to date, ion-ion interaction, ion-dipole and dipole-dipole forces have proved to be inefficient in the detection of anions in water.

One exciting alternative could be the utilization of the halogen bonding in the design of new anion sensors. The term halogen bonding (XB) is used in analogy with the well known hydrogen bonding (HB) and is the noncovalent bonding interaction between halogen atoms that function as electrophilic centres (Lewis acids) and neutral or anionic Lewis bases.

The aims of this project are the synthesis of brand new halogen-bonding receptors that can be exploited as a sensor by the incorporation of signalling groups in their structures. The appropriate functionalization of these receptors will allow the surface assembly and will lead to the development of a novel device for the sensing of anion and constitute a significant step in the direction of fabricating new materials.

The combined processes of molecular-scale recognition and surface assembly offer a powerful route to the development of refined sensing systems and, more generally, new technological devices based on controlling and analysing interactions on the nanometre scale. The design and construction of receptors which can selectively recognise and sense anionic guest species via a macroscopic physical response is a current area of chemical sensor technology receiving considerable attention