Chiral Polyurethane Synthesis Leading to π-Stacked 2/1-Helical Polymer and Cyclic Compounds

Abstract

)-1,1'-Bi(2-naphthol) was reacted with 1,4-phenylene diisocyanate leading to a mixture of linear polyurethane and cyclic compounds including a cyclic dimer and a cyclic trimer. The structure of the cyclic dimer was elucidated by X-ray crystal structure analysis. The polymer was proposed to possess a rather stiff, π-stacked, 2/1-helical conformation on the basis of NMR, CD, and UV spectra and molecular dynamics simulations. The conformation was stable in the range of temperature of 0-60 °C.