A one‐electron L.C.A.O.M.O. treatment of hydrocarbon negative ions

Abstract

Abstract It is shown that the one‐electron L.C.A.O.M.O. treatment is much more reliable for hydrocarbon mono‐ and di‐negative ions than for hydrocarbon molecules. The results of this treatment in which both the interaction between non‐adjacent 2p‐orbitals and overlap have been included, have been compared with polarographic half‐wave potentials, giving a mean value of the resonance parameter for adjacent 2p‐orbitals: β′ o = −2.60 ± 0.030 eV. It appears that by neglecting both interaction between non‐neighbouring 2p‐orbitals and overlap the same mean value is obtained, whereas the inclusion of overlap only, leads to a noticeably less negative value: β′ o = −2.30 ± 0.020 eV. Apparently these effects of overlap and interaction between non‐neighbouring 2p‐orbitals compensate each other.