Pyrrolidinium Ionic Liquid Crystals
Data(s) |
05/01/2009
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Resumo |
N-Alkyl-N-methylpyrrolidinium cations have been used for the design of ionic liquid crystals, including a new type of uranium-containing metallomesogen. Pyrrolidinium salts with bromide, bis(trifluoromethylsulfonyl)-imide, tetrafluoroborate, hexafluorophosphate, thiocyanate, tetrakis(2-thenoyltrifluoroacetonato)europate(III) and tetrabromouranyl] counteranions were prepared. For the bromide salts and tetrabromouranyl compounds, the chain length of the alkyl group CnH2n+1 was varied from eight to twenty carbon atoms (n =8. 10-20). The compounds show rich mesomorphic behaviour: highly ordered smectic phases (the crystal smectic E phase and the uncommon crystal smectic T phase), smectic A phases, and hexagonal. columnar phases were observed, depending on chain length and anion. This work gives better insight into the nature and formation of the crystal smectic T phase, and the Molecular requirements for the appearance of this highly ordered phase. This uncommon tetragonal mesophase is thoroughly discussed on the basis of detailed powder X-ray diffraction experiments and in relation to the existing literature. Structural models are proposed for self-assembly of the molecules within the smectic layers. In addition, the photophysical properties of the compounds containing a metal complex anion were investigated. For the uranium-containing mesogens, luminescence can be induced by dissolving them in an ionic: liquid matrix. The europium-containing compound shows intense red photoluminescence with high colour Purity. |
Identificador |
http://dx.doi.org/10.1002/chem.200801566 http://www.scopus.com/inward/record.url?scp=58449096968&partnerID=8YFLogxK |
Idioma(s) |
eng |
Direitos |
info:eu-repo/semantics/restrictedAccess |
Fonte |
Goossens , K , Lava , K , Nockemann , P , Van Hecke , K , Van Meervelt , L , Driesen , K , Gorller-Walrand , C , Binnemans , K & Cardinaels , T 2009 , ' Pyrrolidinium Ionic Liquid Crystals ' Chemistry-a European Journal , vol 15 , no. 3 , pp. 656-674 . DOI: 10.1002/chem.200801566 |
Palavras-Chave | #/dk/atira/pure/subjectarea/asjc/1600 #Chemistry(all) |
Tipo |
article |