Synthesis, helicity, and low infrared emissivity of optically active poly(N-propargylamide)s bearing stigmasteryl moieties

Novel chiral N -propargylamide based on stigmasterol (M1, HC CCH 2 NHCOCH 2 CH 2 COO-R, R = stigmasteryl) and achiral N -propargylamide based on pivalic acid (M2) were prepared and (co)polymerized with rhodium zwitterions catalyst in CHCl 3 to afford helical polyacetylenes with moderate molecular weights (8997–26777) in good yields. The polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), 1 H nuclear magnetic resonance ( 1 H NMR), gel permeation chromatography (GPC). Ultraviolet–visible spectroscopy (UV–Vis) and circular dichroism (CD) absorption spectra demonstrated that the as-prepared polymers could form helical structures with a preferential helicity. The formation of hydrogen bonds of poly(M1) in CHCl 3 was investigated according to the solution sate IR spectroscopic data . The single-handed helical conformation and polymerization degree of the new-typed poly( N -propargylamide)s could be controlled by the changing the feed ratio of chiral and achiral monomers . Furthermore, the infrared emissivity values (0.536–0.798) of copolymers were investigated at 8–14  μ m by the Infrared Emissometer.