an ab initio scf-mo study of conformational properties of cyclodeca-1,2,3-triene

ab initio calculation at hf/6-31g* level of theory for geometry optimization and mp2/6-31g*//hf/6-31g* for a single point total energy calculation are reported for the important energyminimumconformations and transition-state geometries of of cyclodeca-1,2,3-triene (1). the mostfavorable conformation of 1 is a unsymmetrical twist-chair (1-tc) structure. degenerateinterconversion of 1-tc with itself can take place via cs symmetric half-chair (1-hc, cs). thecalculated energy barrier for this processes is 30.3 kj mol-1, respectively. the twist (1-twist)conformation of the 1, with c2 symmetry, is calculated to be more unstable than the twist-chair(1-tc, c1) geometry by 12.4 kj mol-1. interconversion between 1-tc and 1-twist conformationstakes place via the unsymmetrical transition state, which is 50.3 kj mol-1 above 1-tc form. theboat (c1) geometry of 1 is higher in energy by 19.1 kj mol-1, respectively. ring inversion in twistchairand boat conformations takes place via c2 symmetric 1-tb (1-hc, c2) form and requires65.6 kj mol-1.