Supramolecular Helical Structure of the Stereocomplex Composed of Complementary Isotactic and Syndiotactic Poly(methyl methacrylate)s as Revealed by Atomic Force Microscopy

A long-standing question in polymer chemistry has been addressed by AFM, which revealed the helical conformation, handedness, and helical pitch (0.92 nm) of the title stereocomplex formed from a 1:2 mixture of the named polymers (it- and st-PMMA). The results provide convincing evidence for a triple-stranded helix (see structure against a background of the AFM image) as a plausible model for the stereocomplex.