DENSITY-FUNCTIONAL THEORY STUDIES OF 4-PI-ELECTRON SYSTEMS

The potential energy surfaces of oxirene and diazirinyl anion are char acterised by means of density functional theory. A number of stationar y points on the Kohn-Sham/BLYP surfaces is located and characterised b y analytic second derivatives of the energy. An interconversion path f or ketene, which is thought to be part of a prototype Wolff rearrangem ent, is estimated from this information and compared with recent, high -level ab initio computations. The deprotonation energy of diazirine i s calculated and possible structures of the resulting anion are charac terised and compared with ab initio methods. Oxirene (C-2v) and diazir inyl anion (C-s) are predicted to be transition states, which is at va riance with the best ab initio calculations.