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|Título:||Chiroptical and emissive properties of a calixarene-containing chiral poly (P-phenylene ethynylene) with enantioselective recognition ability|
|Autor:||Prata, José Virgílio Coelho|
Costa, Alexandra Isabel Paulo
Pinto, Hugo D.
|Palavras-chave:||Containing Conjugated Polymers|
|Editora:||Royal Society of Chemistry|
|Citação:||PRATA, José Virgílio Coelho; [et al] – Chiroptical and emissive properties of a CalixArene-containing chiral poly (P-Phenylene Ethynylene) with enantioselective recognition ability. Polymer Chemistry. ISSN: 1759-9954. Vol. 5, nr. 19 (2014), pp. 5793-5803|
|Resumo:||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-calixKlarene units and chiral side-chains on the polymer skeleton prevents efficient pi-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)-alpha-methylbenzylamine were examined. It was found that a significant enantiodiscrimination is exhibited by the calixarene-based polymer in the aggregate state.|
|Aparece nas colecções:||ISEL - Eng. Quim. Biol. - Artigos|
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