Chiral power change upon photoisomerization in twisted nematic liquid crystals
In this work, we use the photoisomerization of azobenzenes, a phenanthrospirooxazine, and a fulgide in a twisted nematic liquid crystalline phase to change the chiral twisting power of the system. The changes are probed by the rotatory power of linearly polarized light. Time resolved and steady stat...
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todo:paper_13861425_v142_n_p94_Simoncelli2023-10-03T16:12:17Z Chiral power change upon photoisomerization in twisted nematic liquid crystals Simoncelli, S. Aramendía, P.F. Azobenzenes Chiral power change Liquid crystals Photochromism Photoisomerization Spirooxazine Activation energy Azobenzene Chemical modification Liquid crystals Liquids Photochromism Photoisomerization Stereochemistry Absorption characteristics Chemical compositions Chiral power change Linearly polarized light Microscopic ordering Spirooxazines Twisted nematic Twisted nematic liquid crystals Nematic liquid crystals azo compound azobenzene chemistry isomerism light liquid crystal phase transition photochemistry thermodynamics Azo Compounds Isomerism Light Liquid Crystals Phase Transition Photochemical Processes Thermodynamics In this work, we use the photoisomerization of azobenzenes, a phenanthrospirooxazine, and a fulgide in a twisted nematic liquid crystalline phase to change the chiral twisting power of the system. The changes are probed by the rotatory power of linearly polarized light. Time resolved and steady state experiments are carried out. The chiral change and the photoisomerization process have similar characteristic recovery times and activation energy, thus probing that the change is induced by the modification in the chemical composition of the photochromic dopant system. The amplitude of the light twisting power change correlates with the order change in the liquid crystal (LC) but not with the modification in the absorption characteristics of the system. This indicates that the driving force of the chiral change is the microscopic order modification in the LC phase that affects the helical pitch of the phase. © 2015 Published by Elsevier B.V. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_13861425_v142_n_p94_Simoncelli |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
Azobenzenes Chiral power change Liquid crystals Photochromism Photoisomerization Spirooxazine Activation energy Azobenzene Chemical modification Liquid crystals Liquids Photochromism Photoisomerization Stereochemistry Absorption characteristics Chemical compositions Chiral power change Linearly polarized light Microscopic ordering Spirooxazines Twisted nematic Twisted nematic liquid crystals Nematic liquid crystals azo compound azobenzene chemistry isomerism light liquid crystal phase transition photochemistry thermodynamics Azo Compounds Isomerism Light Liquid Crystals Phase Transition Photochemical Processes Thermodynamics |
spellingShingle |
Azobenzenes Chiral power change Liquid crystals Photochromism Photoisomerization Spirooxazine Activation energy Azobenzene Chemical modification Liquid crystals Liquids Photochromism Photoisomerization Stereochemistry Absorption characteristics Chemical compositions Chiral power change Linearly polarized light Microscopic ordering Spirooxazines Twisted nematic Twisted nematic liquid crystals Nematic liquid crystals azo compound azobenzene chemistry isomerism light liquid crystal phase transition photochemistry thermodynamics Azo Compounds Isomerism Light Liquid Crystals Phase Transition Photochemical Processes Thermodynamics Simoncelli, S. Aramendía, P.F. Chiral power change upon photoisomerization in twisted nematic liquid crystals |
topic_facet |
Azobenzenes Chiral power change Liquid crystals Photochromism Photoisomerization Spirooxazine Activation energy Azobenzene Chemical modification Liquid crystals Liquids Photochromism Photoisomerization Stereochemistry Absorption characteristics Chemical compositions Chiral power change Linearly polarized light Microscopic ordering Spirooxazines Twisted nematic Twisted nematic liquid crystals Nematic liquid crystals azo compound azobenzene chemistry isomerism light liquid crystal phase transition photochemistry thermodynamics Azo Compounds Isomerism Light Liquid Crystals Phase Transition Photochemical Processes Thermodynamics |
description |
In this work, we use the photoisomerization of azobenzenes, a phenanthrospirooxazine, and a fulgide in a twisted nematic liquid crystalline phase to change the chiral twisting power of the system. The changes are probed by the rotatory power of linearly polarized light. Time resolved and steady state experiments are carried out. The chiral change and the photoisomerization process have similar characteristic recovery times and activation energy, thus probing that the change is induced by the modification in the chemical composition of the photochromic dopant system. The amplitude of the light twisting power change correlates with the order change in the liquid crystal (LC) but not with the modification in the absorption characteristics of the system. This indicates that the driving force of the chiral change is the microscopic order modification in the LC phase that affects the helical pitch of the phase. © 2015 Published by Elsevier B.V. |
format |
JOUR |
author |
Simoncelli, S. Aramendía, P.F. |
author_facet |
Simoncelli, S. Aramendía, P.F. |
author_sort |
Simoncelli, S. |
title |
Chiral power change upon photoisomerization in twisted nematic liquid crystals |
title_short |
Chiral power change upon photoisomerization in twisted nematic liquid crystals |
title_full |
Chiral power change upon photoisomerization in twisted nematic liquid crystals |
title_fullStr |
Chiral power change upon photoisomerization in twisted nematic liquid crystals |
title_full_unstemmed |
Chiral power change upon photoisomerization in twisted nematic liquid crystals |
title_sort |
chiral power change upon photoisomerization in twisted nematic liquid crystals |
url |
http://hdl.handle.net/20.500.12110/paper_13861425_v142_n_p94_Simoncelli |
work_keys_str_mv |
AT simoncellis chiralpowerchangeuponphotoisomerizationintwistednematicliquidcrystals AT aramendiapf chiralpowerchangeuponphotoisomerizationintwistednematicliquidcrystals |
_version_ |
1782026949492736000 |