STEREOCHEMICAL EQUILIBRIUM AND CONFIGURATIONAL STATISTICS IN OLIGOMERS OF POLY(VINYL CHLORIDE)

Stereochemical equilibration of 2,4-dichloro-n-pentane (DCP) in DMSO at 70° in the presence of LiCl yields a mixture containing 36.4 ± 0.3% of the me so isomer. The statistical weight parameter (n) evaluated from this result is used for theoretical calculation of the proportions of various conformers in meso and racemic DCP, and also in the three diastereoisomers of 2,4,6-trichloro-n-heptane (TCH). Calculations for TCH are compared with estimates of Doskočilová and coworkers from nmr coupling constants. It is shown that the less-favored conformations, often ignored, contribute appreciably to the conformer populations of the TCH isomers. © 1969, American Chemical Society. All rights reserved.