A molecular orbital study of (+)-car-2-ene: Fully optimized STO-3G structures

Abstract

Fully optimized structures of the pseudo boat and pseudo chair conformers of (+)-car-2-ene have been calculated using the minimal STO-3G basis. The results show that the pseudo chair conformer is more stable than the pseudo boat conformer, the energy difference being 4.9 kJ mol −1. The calculated structure of the two conformers agrees fairly closely with gas phase electron diffraction results for similar compounds, the largest discrepancy being the underestimation of the length of the carbon-carbon double bond and the carbon-hydrogen bond lengths. It is concluded that the minimal STO-3G basis is fairly reliable in predicting molecular structures even for these rather complicated bicyclic compounds.