Synthesis of a pyrrole-based methine bridge type liquid-crystalline conjugated polymer

Conjugated polymers consisting of pyrrole or an N-substituted pyrrole bridged by methine with a mesogenic group were synthesized. Chemical structures of the products were confirmed with IR, NMR, UV-visible (UV-vis) spectroscopy, and gel permeation chromatography analysis. Liquid crystallinity was examined with differential scanning calorimetry measurements and polarizing optical microscopy observations. Liquid crystal domains of the polymer were macroscopically oriented in one direction by an external magnetic force (10 Tesla). The polymer orientation was confirmed by optical microscopy and X-ray analysis. One of the polymers exhibited a striated fan-shaped texture when observed with a polarizing optical microscope. This is attributed to the formation of a chiral smectic C (SmC*) phase, which is a property of ferroelectricity. Spontaneous polarization of the polymer occurred at 110 nC/cm(2). (C) 2004 Wiley Periodicals, Inc.