“Edge” or “Vertex” Inversion at Phosphorus in the cis – trans Isomerization of Diazadiphosphetidines? Model MNDO and ab initio Molecular Orbital Calculations

Abstract

Ab initio (3-21G(*), MP2/3-21G(*), MP2/3-21G(*)) molecular orbital calculations show that the cis - trans interconversion of diazadiphosphetidines proceeds rather via an “edge” inversion than the classical “vertex” inversion at phosphorus. The semiempirical MNDO results are largely of the same quality as those obtained with the 3-21G(*) basis.