Kinetics of thermal cis-trans isomerization in a phototropic azobenzene-based single-component liquid crystal in its nematic and isotropic phases
Single-component azobenzene-based phototropic liquid crystals (PtLC) are promising materials that have started to be explored for photonic applications. One of the essential factors determining the applicability of these materials is the rate of the thermally driven cis - trans isomerization. In thi...
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Published in | Physical chemistry chemical physics : PCCP Vol. 2; no. 4; pp. 294 - 2913 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
England
Royal Society of Chemistry
24.01.2018
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Subjects | |
Online Access | Get full text |
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Summary: | Single-component azobenzene-based phototropic liquid crystals (PtLC) are promising materials that have started to be explored for photonic applications. One of the essential factors determining the applicability of these materials is the rate of the thermally driven
cis
-
trans
isomerization. In this paper, the kinetics of the thermal back
cis
-to-
trans
reaction in a pure 4-hexyl-4′-methoxyazobenzene (6-AB-O1) compound in its isotropic liquid and nematic phases is studied (the undoped LC). The reaction rate constants, activation energies and thermal activation parameters were determined based on spectroscopic studies. The reaction kinetics is compared to that measured for the compound dissolved in chloroform. The results demonstrate that the thermal back reaction depends on the phase and molecular environment of the
cis
-isomer. Moreover, the effect of temperature on the absorption spectra of 6-AB-O1 in its isotropic, nematic and crystalline phases is examined. The changes in the compound's absorption spectra in the respective phases have been correlated to the positional order parameter
S
.
Kinetics of thermal
cis-trans
isomerization of the single-component azobenzene-based phototropic liquid crystal in its isotropic liquid and nematic phases is studied. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1463-9076 1463-9084 |
DOI: | 10.1039/c7cp06820d |