NONBONDING MOLECULAR-ORBITALS AND THE CHEMISTRY OF NONCLASSICAL ORGANIC-MOLECULES

Professor Ramsden explores common features of the bonding and modes of reaction of a large and diverse family of 'non-classical' organic molecules, which includes 1,3-dipoles, hypervalent compounds, betaines, and ylides, and discusses their relationship to the transition states of S(N)2 reactions. All these molecules can be considered to contain three-centre, four-election bonds and the associated non-bonding molecular orbitals influence structure and reactivity. Two common modes of reaction, which are described as ligand coupling and syn-addition, are recognized and examples of these transformations are discussed.