Professor David Allen is Emeritus professor of Chemistry at Sheffield Hallam University, UK. His main research interests are in phosphonium salts and related compounds. Current interests include the preparation of phosphonioalkyl derivatives of biologically active molecules, the phosphonioalkyl group facilitating the passage of the biologically active agent through cell membranes, and studies of the formation of biologically active surface-functionalised gold nanoparticles. Professor John C Tebby is a retired organophosphorus chemist, formerly at Keele University, UK. Dr David Loakes undertakes nucleic acid research at the Medical Research Council, Laboratory of Molecular Biology, Cambridge, UK.