Research output: Contribution to journal › Article › peer-review
Liquid crystalline dihydroazulene photoswitches. / Petersen, Anne Ugleholdt; Jevric, Martyn; Mandle, Richard J.; Davis, Edward J.; Cowling, Stephen J.; Goodby, John W.; Nielsen, Mogens Brøndsted.
In: RSC Advances, Vol. 5, No. 109, 13.10.2015, p. 89731-89744.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Liquid crystalline dihydroazulene photoswitches
AU - Petersen, Anne Ugleholdt
AU - Jevric, Martyn
AU - Mandle, Richard J.
AU - Davis, Edward J.
AU - Cowling, Stephen J.
AU - Goodby, John W.
AU - Nielsen, Mogens Brøndsted
PY - 2015/10/13
Y1 - 2015/10/13
N2 - A large selection of photochromic dihydroazulene (DHA) molecules incorporating various substituents at position 2 of the DHA core was prepared and investigated for their ability to form liquid crystalline phases. Incorporation of an octyloxy-substituted biphenyl substituent resulted in nematic phase behavior and it was possible to convert one such compound partly into its vinylheptafulvene (VHF) isomer upon irradiation with light when in the liquid crystalline phase. This conversion resulted in an increase in the molecular alignment of the phase. In time, the meta-stable VHF returns to the DHA where the alignment is maintained. The systematic structural variation has revealed that a biaryl spacer between the DHA and the alkyl chain is needed for liquid crystallinity and that the one aromatic ring in the spacer cannot be substituted by a triazole. This work presents an important step towards employing the dihydroazulene-vinylheptafulvene photo/thermoswitch in photoactive liquid crystalline materials.
AB - A large selection of photochromic dihydroazulene (DHA) molecules incorporating various substituents at position 2 of the DHA core was prepared and investigated for their ability to form liquid crystalline phases. Incorporation of an octyloxy-substituted biphenyl substituent resulted in nematic phase behavior and it was possible to convert one such compound partly into its vinylheptafulvene (VHF) isomer upon irradiation with light when in the liquid crystalline phase. This conversion resulted in an increase in the molecular alignment of the phase. In time, the meta-stable VHF returns to the DHA where the alignment is maintained. The systematic structural variation has revealed that a biaryl spacer between the DHA and the alkyl chain is needed for liquid crystallinity and that the one aromatic ring in the spacer cannot be substituted by a triazole. This work presents an important step towards employing the dihydroazulene-vinylheptafulvene photo/thermoswitch in photoactive liquid crystalline materials.
UR - http://www.scopus.com/inward/record.url?scp=84946036832&partnerID=8YFLogxK
U2 - 10.1039/c5ra18649h
DO - 10.1039/c5ra18649h
M3 - Article
AN - SCOPUS:84946036832
VL - 5
SP - 89731
EP - 89744
JO - AIP Advances
JF - AIP Advances
SN - 2046-2069
IS - 109
ER -