New U-shaped Liquid Crystals Azobenzene Derived from Catechol for Photoswitching Properties
A new series of liquid crystals whose molecular structure consists of a U-shaped unit as a central core and two rod-like azobenzenes as the peripheral units are synthesized. The mesomorphic properties were investigated by differential scanning calorimetry, polarizing optical microscopy and X-ray d...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2015
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| Online Access: | http://umpir.ump.edu.my/id/eprint/8118/ http://umpir.ump.edu.my/id/eprint/8118/1/New%20U-Shaped%20Liquid%20Crystals%20Azobenzene%20Derived%20From%20Catechol%20for%20Photoswitching%20Properties.pdf |
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| author | Lutfor, M. R. Biswas, Tapan Kumar Sarkar, Shaheen M. M. M., Yusoff Muhammad Nor Fazli, Abd Malek Tschierske, Carsten |
| author_facet | Lutfor, M. R. Biswas, Tapan Kumar Sarkar, Shaheen M. M. M., Yusoff Muhammad Nor Fazli, Abd Malek Tschierske, Carsten |
| author_sort | Lutfor, M. R. |
| building | UMP Institutional Repository |
| collection | Online Access |
| description | A new series of liquid crystals whose molecular structure consists of a U-shaped unit as a central core and two
rod-like azobenzenes as the peripheral units are synthesized. The mesomorphic properties were investigated
by differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction. The existence of nematic and smectic A phase was confirmed by textures and X-ray diffraction. The trans-form of azo compounds showed
a strong band in the UV region at ~365 nm for the π–π* transition, and a weak band in the visible region at
~450 nm due to the n–π* transition. These molecules exhibit a strong photoisomerization behavior in which
trans–cis take 50 and 55 s for compounds L4/5 and L4/6, respectively, whereas cis–trans take place almost 29
and 30 h, respectively. Long thermal back relaxation allows us to realize that optical storage devices with these materials which need longer periods. |
| first_indexed | 2025-11-15T01:33:20Z |
| format | Article |
| id | ump-8118 |
| institution | Universiti Malaysia Pahang |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T01:33:20Z |
| publishDate | 2015 |
| publisher | Elsevier |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | ump-81182018-02-14T07:17:35Z http://umpir.ump.edu.my/id/eprint/8118/ New U-shaped Liquid Crystals Azobenzene Derived from Catechol for Photoswitching Properties Lutfor, M. R. Biswas, Tapan Kumar Sarkar, Shaheen M. M. M., Yusoff Muhammad Nor Fazli, Abd Malek Tschierske, Carsten QD Chemistry A new series of liquid crystals whose molecular structure consists of a U-shaped unit as a central core and two rod-like azobenzenes as the peripheral units are synthesized. The mesomorphic properties were investigated by differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction. The existence of nematic and smectic A phase was confirmed by textures and X-ray diffraction. The trans-form of azo compounds showed a strong band in the UV region at ~365 nm for the π–π* transition, and a weak band in the visible region at ~450 nm due to the n–π* transition. These molecules exhibit a strong photoisomerization behavior in which trans–cis take 50 and 55 s for compounds L4/5 and L4/6, respectively, whereas cis–trans take place almost 29 and 30 h, respectively. Long thermal back relaxation allows us to realize that optical storage devices with these materials which need longer periods. Elsevier 2015-12-18 Article PeerReviewed application/pdf en http://umpir.ump.edu.my/id/eprint/8118/1/New%20U-Shaped%20Liquid%20Crystals%20Azobenzene%20Derived%20From%20Catechol%20for%20Photoswitching%20Properties.pdf Lutfor, M. R. and Biswas, Tapan Kumar and Sarkar, Shaheen M. and M. M., Yusoff and Muhammad Nor Fazli, Abd Malek and Tschierske, Carsten (2015) New U-shaped Liquid Crystals Azobenzene Derived from Catechol for Photoswitching Properties. Journal of Molecular Liquids, 202. pp. 125-133. ISSN 0167-7322. (Published) http://dx.doi.org/10.1016/j.molliq.2014.12.022 doi: 10.1016/j.molliq.2014.12.022 |
| spellingShingle | QD Chemistry Lutfor, M. R. Biswas, Tapan Kumar Sarkar, Shaheen M. M. M., Yusoff Muhammad Nor Fazli, Abd Malek Tschierske, Carsten New U-shaped Liquid Crystals Azobenzene Derived from Catechol for Photoswitching Properties |
| title | New U-shaped Liquid Crystals Azobenzene Derived from Catechol for Photoswitching Properties |
| title_full | New U-shaped Liquid Crystals Azobenzene Derived from Catechol for Photoswitching Properties |
| title_fullStr | New U-shaped Liquid Crystals Azobenzene Derived from Catechol for Photoswitching Properties |
| title_full_unstemmed | New U-shaped Liquid Crystals Azobenzene Derived from Catechol for Photoswitching Properties |
| title_short | New U-shaped Liquid Crystals Azobenzene Derived from Catechol for Photoswitching Properties |
| title_sort | new u-shaped liquid crystals azobenzene derived from catechol for photoswitching properties |
| topic | QD Chemistry |
| url | http://umpir.ump.edu.my/id/eprint/8118/ http://umpir.ump.edu.my/id/eprint/8118/ http://umpir.ump.edu.my/id/eprint/8118/ http://umpir.ump.edu.my/id/eprint/8118/1/New%20U-Shaped%20Liquid%20Crystals%20Azobenzene%20Derived%20From%20Catechol%20for%20Photoswitching%20Properties.pdf |