Synthesis of a series of optically active polythiophene derivatives bearing myrtanoxy group

Abstract

ABSTRACT Polythiophenes bearing myrtanoxy group as a chiral side chain were synthesized via a Migita–Kosugi–Stille coupling reaction. Circular dichroism spectroscopy of the polymers showed that only the polythiophene derivative consisting of thiophene trimers as a monomer repeat unit had optical activity. The number of thiophene rings in the thiophene unit increased, the absorption bands shifted to longer absorption wavelengths. The polymer shows Davydov split type circular dichroism optical absorption due to formation of helical π-stacking structure in 1,2-dichlorobenzene solution. This polymer behaved as a thermotropic liquid crystallinity due to its structural characteristics. Introduction of a derivative of natural compound to polythiophenes affords to yield chiroptically active π-conjugated materials with visible color fluorescence.