Polymerization of acetylenic derivatives. XXVII. Synthesis and properties of isomeric poly‐<i>N</i>‐ethynylcarbazole

Abstract

Abstract Poly‐ N ‐ethynylcarbazole (PEC) was prepared thermally, by using Ziegler‐Natta catalysts, and also by using TiCl 4 and phosphine complexes for initiation. The spectral data (infrared, NMR, x‐ray diffraction, and ultraviolet) were best interpreted based on a cis‐transoidal/cis‐cisoidal stereoblock structure for (both soluble and insoluble) polymers prepared by Ziegler‐Natta catalysts and on a trans‐cisoidal structure for the polymers prepared with the other catalysts. The cis‐transoidal/cis‐cisoidal stereoblock structure isomerized thermally into a trans‐cisoidal structure, at temperatures which were dependent on the type of initiation.