Chiroptical and emissive properties of a cali

Polymer Chemistry

Journal Article

Supramolecular chirality was achieved in solutions and thin films of a calixarene-containing chiral aryleneethynylene copolymer. The observed chiroptical activity, which is primarily allied with the formation of aggregates of high molecular weight polymer chains, is the result of a combination of intrachain and interchain effects. The former arises by the adoption of an induced helix-sense by the polymer main-chain while the latter comes from the exciton coupling of aromatic backbone transitions. The co-existence of bulky bis-calix[4]arene units and chiral side-chains on the polymer skeleton prevents efficient π-stacking of neighbouring chains, keeping the chiral assembly highly emissive. In contrast, for a model polymer lacking calixarene moieties, the chiroptical activity is dominated by strong interchain exciton couplings as a result of more favourable packing of polymer chains, leading to a marked decrease of photoluminescence in the aggregate state. The enantiomeric recognition abilities of both polymers towards (R)- and (S)-α- methylbenzylamine were examined. It was found that a significant enantiodiscrimination is exhibited by the calixarene-based polymer in the aggregate state. © 2014 the Partner Organisations.

J.V. Prata

A.I. Costa

G. Pescitelli

Publication

Year of publication: 2014

Identifiers

ISSN: 17599954

Locators

DOI: 10.1039/c4py00729h

Alternative Titles