Semi-empirical SCF–MO study of the molecular and electronic structures of the cation-radicals derived from simple ethers and acetals

Abstract

Molecular and electronic structures have been calculated, using the MNDO method, for the cation-radicals derived from a number of simple ethers and acetals, both cyclic and acyclic. For Me₂O⁺ and Et₂O⁺ both inter- and intra-molecular hydrogen atom transfers, from carbon to oxygen, are exothermic processes. The cation-radical of 1,3-dioxolane is calculated to be planar, but those from 1,3-dioxane and 1,3,5-trioxane contain planar COCOC fragments with the sixth ring atom displaced from this plane; the calculated spin-densities in these two cations allow an assignment of the observed e.s.r. Spectra to be made. No definitive distinction could be made between the boat and chair conformers of the 1,4-dioxane cation-radical.