Anions cannot diffuse passively through biological membranes and membrane-bound proteins mainly govern the transmembrane movement of these charged species. The use of synthetic compounds that are able to facilitate the transmembrane transport of anions is a fascinating and burgeoning topic. The study of facilitated anion transport across lipid bilayers is an emerging field in supramolecular and bioorganic chemistry. In this critical review we describe the recent research progress in this area, focusing on literature published during the years 2007–2009. An overview of the assays that are used in the transmembrane transport of anions is also included (158 references).

New approaches to the transmembrane transport of anions are discussed in this review.

The development of discrete molecular carriers for anions and supramolecular anion channels are reviewed followed by an overview of the use of these systems in biological systems as putative treatments for diseases such as cystic fibrosis and cancer.

A pyrrolylamidothiourea deprotonates in the presence of one equivalent of not only fluoride, but also acetate, benzoate or dihydrogen phosphate in DMSO solution with structural studies using synchrotron radiation confirming thiourea deprotonation in the solid state.