Poly(3-alkyl-co-3,4-dialkylthiophene) copolymers: A series of conjugated materials with tunable energy-gap.

The copolymerization of 3-alkylthiophene aad 3,4-dialkylthiophene units in well defined ratios leads to materials in which it is possible to modulate continuously the electronic properties sucha s the conjugationl ength and the energy-gapT. he solublem aterialsh ave optical properlies depending on tle chemical composition of the chain. A macromolecular and optical characterisatiohna sb eenp erformedo n two copolyner series