4. Conclusions
Chiral t-conjugated polymers can be an important issue in the field of materials science from the view point of comparing basic science to bio-polymers. Industrial applications are expected for opto-electronic organic materials.
We synthesized low-band polymers with chiral side chains under oxidative conditions An introduction of alkyl side chains allows solubility of C-polyl and (+-poly2 in organic solvents such as THF or CHCl 3. Bandgap of the polymers is estimated to be 1.26 eV evaluated from optical absorption spectroscopy. Optical rotations of the polymers were identified in film state with ORD spectroscopy Furthermore, the polymers showed complementary mimor-image optical rotations. This can be a first example of the synthesis of poly(isothianaphthene methine)s with chiral side chains showing chiroptical activity in the visible range. Doping and dedoping of an electron acceptor for the polymers may afford tuning of optical activity. The polymers may be applied for optical sensing devices by combining the function of optically active low-bandgap character with dopable properties.