Solvent Acts as the Referee in a Match-Up Between Charged and Preorganized Receptors

Helical aromatic foldamers with tubular cavities capable of accommodating multiple halide ions

A series of pyridinium-indolocarbazole oligomers with different lengths, capable of adopting helical conformations with tubular cavities, has been synthesized. These oligomers can accommodate two, three, or four iodide ions in a linear arrangement within their cavities, which can be exchanged with other halides.

Solvent effects in anion recognition

Anion recognition is pertinent to a range of environmental, medicinal and industrial applications. Recent progress in the field has relied on advances in synthetic host design to afford a broad range of potent recognition motifs and novel supramolecular structures capable of effective binding both in solution and at derived molecular films. However, performance in aqueous media remains a critical challenge. Understanding the effects of bulk and local solvent on anion recognition by host scaffolds is imperative if effective and selective detection in real-world media is to be viable. This Review seeks to provide a framework within which these effects can be considered both experimentally and theoretically. We highlight proposed models for solvation effects on anion binding and discuss approaches to retain strong anion binding in highly competitive (polar) solvents. The synthetic design principles for exploiting the aforementioned solvent effects are explored.