NMR of molecular endofullerenes dissolved in a nematic liquid crystal
| Autor: | Benno Meier, Malcolm H. Levitt, Karel Kouřil, Shamim Alom, Richard J. Whitby, John Gräsvik, Christopher Wickens |
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| Rok vydání: | 2017 |
| Předmět: |
Phase transition
Fullerene General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Condensed Matter::Soft Condensed Matter MBBA Crystallography chemistry.chemical_compound chemistry Liquid crystal Chemical physics Phase (matter) Physics::Atomic and Molecular Clusters Endohedral fullerene Proton NMR Molecule Physical and Theoretical Chemistry 0210 nano-technology |
| Zdroj: | Physical chemistry chemical physics : PCCP. 19(19) |
| ISSN: | 1463-9084 |
| Popis: | We report the NMR of the molecular endofullerenes H2@C60, H2O@C60 and HF@C60 dissolved in the nematic liquid crystal N-(4-methoxybenzylidene)-4-butylaniline (MBBA). The 1H NMR lines of H2 and H2O display a doublet splitting due to residual dipole–dipole coupling. The dipolar splitting depends on temperature in the nematic phase and vanishes above the nematic–isotropic phase transition. The 19F spectrum of HF@C60 dissolved in MBBA displays a doublet splitting in the nematic phase, with contributions from the 1H–19F dipole–dipole coupling and J-coupling. The phenomena are analyzed using a model in which the fullerene cages acquire a geometrical distortion, either through interaction with the liquid crystal environment, or through their interaction with the endohedral molecules. The distorted cages become partially oriented with respect to the liquid crystal director, and the endohedral molecules become partially oriented with respect to the distorted cages. |
| Databáze: | OpenAIRE |
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