A force field for secondary chlorides

Abstract

A force field has been derived for monochloro- and 2,4-dichloro-hydrocarbons. The Snyder-Schachtschneider force field for hydrocarbons was used as a starting point, the constants associated with the secondary chlorine being determined from an assignment of the gas phase spectrum of 2-chloropropane and the carbon---chlorine stretching frequencies of the three isomers of 2-chlorobutane. The force field was tested on 3-chloropentane, axial and equatorial monochlorocyclohexane, and the most stable conformations of dl and meso 2,4-dichloropentane, giving good agreement in all of these cases. The conformation dependence of the carbon---chlorine stretching frequency is thus shown to derive primarily from structural differences between conformers.