Conformational energy surfaces of triplet‐state isomeric methyloxiranes

A conformational study was carried out on the three ring‐opened structures of triplet methyloxirane with a minimal Gaussian basis set, within the unrestricted Hartree–Fock framework. For the two structuresenergy surfaces E (θ 1 , θ 2 ) were generated, where θ 1 measures the methyl rotation and θ 2 is associated with the torsion about the other CC bond. For the third structurean energy hypersurface E (θ 1 , θ 2 , θ 3 ) was generated, where energy was a function of methyl rotation θ 1 and two nonequivalent CO rotations θ 2 and θ 3 . Analysis of the surfaces revealed the locations and relative energies of the critical points (minima, saddle points, and maxima). The overall stereochemical finding was that these ring‐opened triplet C 3 H 6 O species possessed rather flexible structures.