Lasse Postmyr
Mar 24, 1994
Citations
0
Influential Citations
3
Citations
Journal
Journal of Molecular Structure
Abstract
Abstract The molecular structures and conformational compositions of 1-bromo-3-chloropropane (BCP) and 1,3-diiodopropane (DIP) have been studied by gas-phase electron diffraction at 27 and 38°C, respectively. BCP was found to exist as a mixture of the following four conformers, with estimated mole fractions in brackets: AA (0.1), AG (0.3), GA (0.1) and GG (0.5). These estimated mole fractions correspond to the following relative conformational energies: Δ E AA = 0.5 kcal mol −1 , Δ E AG = 0.3 kcal mol −1 , Δ E GA = 0.9 kcal mol −1 and Δ E GG = 0.0 kcal mol −1 . DIP was found to exist as a mixture of AA, AG and GG. The mole fractions and uncertainties estimated at 2σ were found to be 0.05(9), 0.40(21) and 0.55(24), respectively. This corresponds to the following relative conformational energies: Δ E AA ≈ 1.1 kcal mol −1 , Δ E AG = 0.7(6) kcal mol −1 and Δ E GG = 0.0 kcal mol −1 . In order to conduct a more detailed investigation of the conformational geometries, results from molecular mechanics (MM) calculations have been included in the analysis.