Macromolecules, Vol.48, No.22, 8121-8127, 2015
Expression of Chirality in a Conjugated Polymer without Any Excess of Chiral Centers
Chirality is typically expressed in chiral molecules, including polymers. In this work, we demonstrate that chirality can also be expressed in a polymer molecule that does not contain any excess of chiral centers; in this specific material the chirality is evoked by a specific order of manipulations ("events"). The polymer studied is an all-conjugated block copoly(3-alkylthiophene), in which the first block contains exactly the same amount of (S)-enantiomers as the second block (R)-enantiomers. Moreover, to introduce a distinct difference in solubility required to have multiple consecutive events the S-block is composed of S-monomers copolymerized with octyl-functionalized thiophene monomers, while the R-block is composed of R-monomers in combination with amine-functionalized thiophene monomers. By making use of the difference in solubility of both blocks, a chiral response can be evoked from this polymer without the need of a chiral trigger.