Synthesis, spectroelectrochemistry and thermochromism of regioregular head-to-tail oligo- and poly-[3-aryloxyhexylthiophenes]

The synthesis of regioregular head-to-tail poly(3-[ω-(p- methoxyphenoxy)hexyl]thiophenes) is reported, together with a study of the effect of sterically demanding 3-substituents on its structure and physical properties (conductivity, spectroelectrochemistry and thermochromism). The polymer is deep red when reduced but optically transparent in its oxidised form. The syntheses of the corresponding regioregular dimer and trimer, i.e. 3,4'-di[(p-methoxyphenoxy)hexyl]-2,2'-bithiophene and 3,4',4'-tri[(p- methoxyphenoxy)hexyl]-2,2' : 5',2'terthiophene are also reported.