3-Chloro-1-propene (allylchloride): gas-phase molecular structture and conformation as determined by electron diffraction
Abstract
A gas-phase study of 3-chloro-1-propene by electron diffraction showed that the most abundant conformer was gauche with a torsional angle τ=120.8(5.4)°, relative to τ = 0 for syn from when all heavy atoms are in the same plane and the chlorine atom is eclipsing the double bond. At 20 and 90°C the amount of the gauche conformer was found to be 82(9) and 78(15)%, respectively. The least-squares refinements of the molecular structure were assisted by a few constraints taken from ab intio calculations. At 90°C the following gauche structure was obtained in terms of ra and L α parameters: r(C=C) = 1.341(5) Å, r(=CC) = 1.506(6) Å, r(CCl) = 1.803(5) Å, ( r(CH)) = 1.081(17) Å, LC=CC = 122.6(1.3)°, LCCCl = 110.0(1.0)°, LClCH = 106.6(2.4)°. Error limits are given as 2σ (σ includes uncertainty due to correlation and systematic errors in the data). The syn form was found to have 2 large root-mean-square torsional amplitude, 20-25°. In connection with the structure analysis a relatively simple valence force field was developed.
- Publication:
-
Journal of Molecular Structure
- Pub Date:
- April 1985
- DOI:
- 10.1016/0022-2860(85)85048-1
- Bibcode:
- 1985JMoSt.128..161S