Syndiotactic structures energy calculations

A RIS model with neighbor interactions is used to calculate mean-square unperturbed dimensions and dipole moments for vinyl chloride chains having degrees of polymerization ranging from x = 1 to 1 50 and stereochemical structures ranging from perfect syndiotacticity to perfect isotacticity. Conformational energies used in these calculations are those which have been established in the analysis based on the stereochemical equilibration of 2,4-dichloro-n-pentane by Flory and Williams (A 002). 

Molecular mechanics techniques are employed to calculate the molecular structure and conformational energies of model compounds for polyphenylmethylsllylene and polysilastyrene. In both isotactic and syndiotactic stereochemical forms. The structural and conformational energy data provided are used to calculate, by application of the RIS theory, the unperturbed chain dimensions, given as the characteristic ratio, and its temperature coefficient. 

MM calculations with full geometry optimization have been carried out to calculate the molecular structure and conformational energies od, ..modeJ -.cpmpounds for poly (phenylmethylsilylene) [-SiPhMe-] and poly(silastyrene) [-SiPhH-SiH2-]. In each case the calculations considered both the isotactic and syndiotactic stereochemical isomeric forms of the model compounds. The structures considered are illustrated in Figures 6 and 7. 

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