Discrimination of Stereochemical Configurations of 2,4-Dichloropentane, 2,3-Dichlorobutane, and Poly (vinyl chloride) by Carbon-13 Nuclear Magnetic Resonance

Abstract

Natural-abundance carbon-13 nuclear magnetic resonance spectra, with proton noise decoupling, have been obtained for pure meso- and rac-2,4-dichloropentane, pure meso- and rac-2,3-dichlorobutane, and two samples of polyvinyl chloride) of different stereochemical configuration. The 13C chemical shifts of the chlorinated hydrocarbon models are interpreted in terms of their rotational isomers. The sensitivity of 13C shifts to stereoisomers was found to be an order of magnitude greater than that of proton shifts. Triad sequences were easily distinguished for poly(vinyl chloride), but the diad, tetrad, or pentad structures may be moee difficult to extract from 13C spectra than from proton spectra taken at high frequency. © 1971, American Chemical Society. All rights reserved.