AbstractInfrared spectra of saturated and unsaturated chlorinated hydrocarbons have been studied using low temperature techniques, including isolation in an inert matrix. The compounds were selected in relation to problems in the understanding of the properties of poly (vinyl chloride).
The physical properties of poly (vinyl chloride) and the capacity to fabricate various products depends on detailed structure and conformation of the polymer chain. Conformational content of model compounds by infrared spectroscopy has been shown to be very valuable in relation to the polymer. In particular, the C-C1 stretching frequency of poly (vinyl chloride) is sensitive to structure and conformation and correlations have been made with these model compounds.
In relation to the determination of the enthalpy difference between conformers (AH e ) by vibrational spectroscopy, a comprehensive review of existing literature is presented for conformational equilibria involving a wide range of compounds.
In the case of saturated chloro-hydrocarbons, vibrational assignments in relation to equilibria between conformers are presented for 2-chlorobutane, isomeric 2,4-dichloropentanes and isomeric 2,4,6-trichloroheptanes.
For unsaturated chloro-hydrocarbons more detailed structural and thermodynamic information has been determined in the case of allyl chloride and 2-chlorobuta-l,3-diene (chloroprene).
Information on these model compounds is critically considered in relation to similar information from poly (vinyl chloride). Some conclusions concerning the polymer are that there are present some conformations which are unfavourable to bKe structure of the polymer chain and which have previously tended to be ignored. Also some previous assumptions concerning the CH2 deformation region of the poly (vinyl chloride) spectrum and mathematical resolution of peaks have been clarified.
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