An abinitio molecular orbital study of isomers on the C2NH5+• and C2NH5 surfaces

The structures and relative energies of seven possible C2NH5+•isomers have been calculated using abinitio molecular orbital theory. Structure optimisations have been performed with a 4-31G basis set, using both the restricted (RHF) and unrestricted (UHF) Hartree–Fock methods. The optimum geometries were then used for single point calculations using the 6-31G* basis set. The relative energies are 1 < 7 < 5 < 3 ≈ 2 ≈ 6 < 4. This order is the same, with the exception of 6, as for isomers on the C2H4O+•surface and the relative energies are very similar to those on the C2H4O+• surface. The structures of the radical cations C2NH5+• are compared with those of the neutral molecules C2NH5.