Association of Stereoregular Poly(methyl methacrylates). 6. Double-Stranded Helical Structure of the Stereocomplex of Isotactic and Syndiotactic Poly(methyl methacrylate)

In 1965 Liquori et al. proposed a model of the stereocomplex of isotactic and syndiotadic poly(methyl methacrylate) (it- and st-PMMA). Although this model could not explain most experimental results, e.g., those of template polymerization, no other models were published. However, Tadokoro et al. expected the structure of the stereocomplex to be closely related to the double-stranded helix of it-PMMA, and recently, Spěváček and Schneider reported that the results of their NMR study are compatible with this idea. In the present paper such a model of the stereocomplex, which is also mentioned by Vorenkamp et al. of our laboratory, is further developed with the aid of energy calculations and X-ray diffraction