Profile of the helical structure of poly(propiolic esters)

Poly(propiolic esters) with chiral substituents have proven to exist in well-ordered helical conformation with an excess of one-handed screw-sense. The main chain of poly(propiolic esters) consists of relatively large helical domains interposed between disordered states, which was evidenced by the chiroptical properties of copolymers from chiral and achiral comonomers. NMR study of various poly(propiolic esters) enabled estimation of not only the activation energy of helix reversal but also the free energy difference between the helical and disordered states.