A theoretical study of diazirine (H2CN2), diazirinyl radical (HCN2) and their related cations (H2CN2+, HCN+2):: molecular structure, energetics and ionization potential

The molecular structures and energetics of diazirine (H2CN2), diazirinyl radical (HCN2) and their related cations (H2CN2+, HCN2+) have been investigated by means of the coupled-cluster method in conjunction with different basis sets. Core cor relation effects and basis set incompleteness have been taken into account in order to obtain best estimates of their equilibrium geometries, C-H bond dissociation energies of diazirine and diazirine cation (H2CN2+), and ionization potentials of diazirine and diazirinyl radical. Adiabatic as well as vertical ionization potentials have been considered. For all the species studied, harmonic vibrational frequencies have also been evaluated in order to obtain zero-point corrections to both ionization potentials and C-H dissociation energies. (C) 2004 Elsevier B.V. All rights reserved.