Star-shaped mesogens with a phloroglucinol or a trimesic acid core and oligobenzoate arms with up to five repeating units have been synthesised. non-conventional mesogens form various columnar mesophases over a broad temperature range. The liquid-crystal phases were characterised by optical microscopy, differential scanning calorimetry, X-ray diffraction, dilatometry and solid-state NMR spectroscopy. In addition to the high-temperature hexagonal columnar phases, the columnar self-assemblies undulate upon cooling and consequently form higher-ordered body-centred orthorhombic columnar 3D structures. A model of E-shaped folded conformers helically displaced along the columns is proposed. Helical preorganisation in the hexagonal phase precedes the transition to the low-temperature phases. Space filling and nano-segregation compete in the self-organisation process, thus aliphatic chains and the polar oligobenzoate scaffold are not perfectly separated in these star-shaped mesogens.
TY - JOUR
AU - Lehmann, Matthias
AU - Jahr, Michael
AU - Donnio, Bertrand
AU - Graf, Robert
AU - Gemming, Sibylle
AU - Popov, Igor
PY - 2008
UR - http://rimsi.imsi.bg.ac.rs/handle/123456789/291
AB - Star-shaped mesogens with a phloroglucinol or a trimesic acid core and oligobenzoate arms with up to five repeating units have been synthesised. non-conventional mesogens form various columnar mesophases over a broad temperature range. The liquid-crystal phases were characterised by optical microscopy, differential scanning calorimetry, X-ray diffraction, dilatometry and solid-state NMR spectroscopy. In addition to the high-temperature hexagonal columnar phases, the columnar self-assemblies undulate upon cooling and consequently form higher-ordered body-centred orthorhombic columnar 3D structures. A model of E-shaped folded conformers helically displaced along the columns is proposed. Helical preorganisation in the hexagonal phase precedes the transition to the low-temperature phases. Space filling and nano-segregation compete in the self-organisation process, thus aliphatic chains and the polar oligobenzoate scaffold are not perfectly separated in these star-shaped mesogens.
PB - Wiley-V C H Verlag Gmbh, Weinheim
T2 - Chemistry-A European Journal
T1 - Star-shaped oligobenzoates: Non-conventional mesogens forming columnar helical mesophases
EP - 3576
IS - 12
SP - 3562
VL - 14
DO - 10.1002/chem.200700922
ER -
@article{
author = "Lehmann, Matthias and Jahr, Michael and Donnio, Bertrand and Graf, Robert and Gemming, Sibylle and Popov, Igor",
year = "2008",
abstract = "Star-shaped mesogens with a phloroglucinol or a trimesic acid core and oligobenzoate arms with up to five repeating units have been synthesised. non-conventional mesogens form various columnar mesophases over a broad temperature range. The liquid-crystal phases were characterised by optical microscopy, differential scanning calorimetry, X-ray diffraction, dilatometry and solid-state NMR spectroscopy. In addition to the high-temperature hexagonal columnar phases, the columnar self-assemblies undulate upon cooling and consequently form higher-ordered body-centred orthorhombic columnar 3D structures. A model of E-shaped folded conformers helically displaced along the columns is proposed. Helical preorganisation in the hexagonal phase precedes the transition to the low-temperature phases. Space filling and nano-segregation compete in the self-organisation process, thus aliphatic chains and the polar oligobenzoate scaffold are not perfectly separated in these star-shaped mesogens.",
publisher = "Wiley-V C H Verlag Gmbh, Weinheim",
journal = "Chemistry-A European Journal",
title = "Star-shaped oligobenzoates: Non-conventional mesogens forming columnar helical mesophases",
pages = "3576-3562",
number = "12",
volume = "14",
doi = "10.1002/chem.200700922"
}
Lehmann, M., Jahr, M., Donnio, B., Graf, R., Gemming, S.,& Popov, I.. (2008). Star-shaped oligobenzoates: Non-conventional mesogens forming columnar helical mesophases. in Chemistry-A European Journal
Wiley-V C H Verlag Gmbh, Weinheim., 14(12), 3562-3576.
https://doi.org/10.1002/chem.200700922
Lehmann M, Jahr M, Donnio B, Graf R, Gemming S, Popov I. Star-shaped oligobenzoates: Non-conventional mesogens forming columnar helical mesophases. in Chemistry-A European Journal. 2008;14(12):3562-3576.
doi:10.1002/chem.200700922 .
