Professor David Allen is Emeritus professor of chemistry at the University of Sheffield, 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.

• Chapter 1: Phosphines and related tervalent phosphorus systems;Chapter 2: Phosphine chalcogenides, phosphonium salts and P-ylides;Chapter 3: Tervalent phosphorus acid derivatives;Chapter 4: Quinquevalent phosphorus acids;Chapter 5: Pentacoordinated and hexacoordinated compounds;Chapter 6: Nucleic acids and nucleotides: mononucleotides;Chapter 7: Nucleotides and nucleic acids: oligo- and polynucleotides;Chapter 8: Phosphazenes