A THEORETICAL INVESTIGATION OF STRUCTURAL, SPECTROSCOPIC AND THERMODYNAMIC PROPERTIES OF CYCLODECANE

Abstract

The torsion potential energy surface for cyclodecane has been examined using molecular mechanics and quantum chemical methods. The boat-chair-boat (BCB) conformer is predicted as the most stable structure at all levels of theory employed, in agreement with low temperature experiments. We found 13 low-energy conformers that cover a range of ~10 kcal mol-1. The relative abundance of the main isomers (named BCB, TBC, TBCC and TCCC) as a function of the temperature is discussed. In addition, energy calculations at high correlated levels of theory (MP4(SDTQ) and CCSD(T)) were for the first time performed for these conformations. In general, the predicted Gibbs population is in fairly good agreement with the experimental data. The simulated IR, VCD and 13 C NMR spectra were obtained showing good accordance with the observed data, providing important features for conformational analysis of cyclodecane.