Synthesis and Properties of a Chiroptically Active Oligomer from 3,4-Ethylenedioxythiophene and (–)-Myrtenal

Oxidative polycondensation of 3,4-ethylenedioxythiophene and (–)-myrtenal was carried out with POCl(3). A π-conjugated system thus constructed consists of aromatic and quinoidal alternating structure linked via methine groups. We examined iodine doping effect for the resultant material with electron spin resonance spectroscopy. Circular dichroism spectra in chloroform solution showed blue-shift with increase of iodine concentration. This result indicates that the doping process can tune chiroptical activity of the chiral π-conjugated system.