American Journal of Nano Research and Applications

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Optical Switching of Azophenol Derivatives in Solution and in Polymer Thin Films: The Role of Chemical Substitution and Environment

Received: 16 November 2014    Accepted: 19 November 2014    Published: 23 December 2014
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Abstract

Design of polymer materials whose properties can be reversibly changed by illumination with light is a technology of particular scientific interest. Such materials contain molecular chromophors, which change their geometry and/or polarity upon absorption of light of a specific wavelength. The most prominent chromophores are azobenzene derivatives. Here, we present a systematic study on azobenzene derivatives in order to quantify the impact of chemical substitution and chemical environment on the dynamics of light-induced trans-cis isomerization (at 368 nm and 355 nm), thermal cis-trans relaxation, and light-induced cis-trans isomerization (at 434 nm). Systems under investigation were 4-hydroxyazobenzene (4-HAB) in acetonitrile (MeCN) solution and in a poly(methylmethacrylate) (PMMA) matrix. These two systems are compared to systems in which 4-HAB is esterified, namely 4-hydroxyazobenzene covalently bound (esterified) to PMMA matrix, and N-(tert-butoxycarbonyl)glycine-4- hydroxyazobenzene (Boc-Gly-4-HAB) in MeCN and in PMMA. Photoisomerization and thermal relaxation kinetics are monitored with UV-vis absorption spectroscopy and accompanied by quantum chemical calculations to shed light into the molecular origin of observed differences in switching properties. We find that the chemical environment (MeCN vs. PMMA) only has minor impacts (~10%) on trans to cis photoisomerization rates. Also, the impact of chemical environment on thermal cis to trans relaxation is small; with relaxation rates in PMMA beeing < 35% smaller compared to rates in MeCN solution. However, the thermal cis to trans relaxation rates of 4-HAB are clearly faster (factor > 400) than the rates of esterified systems. This difference is a clear result of the different substituents on the azobenzene moiety. Quantum chemical calculations suggest that the cis-configuration in the esterified systems is stabilized by an intramolecular H-bond between a carbonyl oxygen on the substituent and an H atom on the phenyl ring. In all systems, the cis to trans isomerization can be significantly accelerated by illumination with 434 nm light. For esterified systems, accelerations by factors of about 5700 – 15500 are observed. In the case of 4-hydroxyazobenzene covalently bound (esterified) to the PMMA matrix, complete light induced transfer from cis to trans is possible. In addition, it features a low thermal cis to trans isomerization rate and acceptable photoinduced trans to cis isomerization properties. With this, the material fulfills the basic requirements of a functional polymer material whose properties can be reversibly changed by illumination with light.

DOI 10.11648/j.nano.s.2014020601.16
Published in American Journal of Nano Research and Applications (Volume 2, Issue 6-1, December 2014)

This article belongs to the Special Issue Advanced Functional Materials

Page(s) 39-52
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Azobenzene Derivatives, Azophenol, Trans - Cis Isomerization, Photoisomerization, Thermal Relaxation, Chemical Environment, Chemical Substitution, Functional Polymer

References
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Author Information
  • Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Faculty of Chemistry and Mineralogy, University of Leipzig, Permoserstrasse 15, 04318 Leipzig, Germany; Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, 11884, Cairo, Egypt

  • Chemical Department, Leibniz Institute of Surface Modification, Permoserstrasse 15, 04318 Leipzig, Germany

  • Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Faculty of Chemistry and Mineralogy, University of Leipzig, Permoserstrasse 15, 04318 Leipzig, Germany

  • Chemical Department, Leibniz Institute of Surface Modification, Permoserstrasse 15, 04318 Leipzig, Germany

  • Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Faculty of Chemistry and Mineralogy, University of Leipzig, Permoserstrasse 15, 04318 Leipzig, Germany

  • Chemical Department, Leibniz Institute of Surface Modification, Permoserstrasse 15, 04318 Leipzig, Germany

  • Chemical Department, Leibniz Institute of Surface Modification, Permoserstrasse 15, 04318 Leipzig, Germany

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    Yasser M. Riyad, Sergej Naumov, Jan Griebel, Christian Elsner, Ralf Hermann, et al. (2014). Optical Switching of Azophenol Derivatives in Solution and in Polymer Thin Films: The Role of Chemical Substitution and Environment. American Journal of Nano Research and Applications, 2(6-1), 39-52. https://doi.org/10.11648/j.nano.s.2014020601.16

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    Yasser M. Riyad; Sergej Naumov; Jan Griebel; Christian Elsner; Ralf Hermann, et al. Optical Switching of Azophenol Derivatives in Solution and in Polymer Thin Films: The Role of Chemical Substitution and Environment. Am. J. Nano Res. Appl. 2014, 2(6-1), 39-52. doi: 10.11648/j.nano.s.2014020601.16

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    Yasser M. Riyad, Sergej Naumov, Jan Griebel, Christian Elsner, Ralf Hermann, et al. Optical Switching of Azophenol Derivatives in Solution and in Polymer Thin Films: The Role of Chemical Substitution and Environment. Am J Nano Res Appl. 2014;2(6-1):39-52. doi: 10.11648/j.nano.s.2014020601.16

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  • @article{10.11648/j.nano.s.2014020601.16,
      author = {Yasser M. Riyad and Sergej Naumov and Jan Griebel and Christian Elsner and Ralf Hermann and Katrin R. Siefermann and Bernd Abel},
      title = {Optical Switching of Azophenol Derivatives in Solution and in Polymer Thin Films: The Role of Chemical Substitution and Environment},
      journal = {American Journal of Nano Research and Applications},
      volume = {2},
      number = {6-1},
      pages = {39-52},
      doi = {10.11648/j.nano.s.2014020601.16},
      url = {https://doi.org/10.11648/j.nano.s.2014020601.16},
      eprint = {https://download.sciencepg.com/pdf/10.11648.j.nano.s.2014020601.16},
      abstract = {Design of polymer materials whose properties can be reversibly changed by illumination with light is a technology of particular scientific interest. Such materials contain molecular chromophors, which change their geometry and/or polarity upon absorption of light of a specific wavelength. The most prominent chromophores are azobenzene derivatives. Here, we present a systematic study on azobenzene derivatives in order to quantify the impact of chemical substitution and chemical environment on the dynamics of light-induced trans-cis isomerization (at 368 nm and 355 nm), thermal cis-trans relaxation, and light-induced cis-trans isomerization (at 434 nm). Systems under investigation were 4-hydroxyazobenzene (4-HAB) in acetonitrile (MeCN) solution and in a poly(methylmethacrylate) (PMMA) matrix. These two systems are compared to systems in which 4-HAB is esterified, namely 4-hydroxyazobenzene covalently bound (esterified) to PMMA matrix, and N-(tert-butoxycarbonyl)glycine-4- hydroxyazobenzene (Boc-Gly-4-HAB) in MeCN and in PMMA. Photoisomerization and thermal relaxation kinetics are monitored with UV-vis absorption spectroscopy and accompanied by quantum chemical calculations to shed light into the molecular origin of observed differences in switching properties. We find that the chemical environment (MeCN vs. PMMA) only has minor impacts (~10%) on trans to cis photoisomerization rates. Also, the impact of chemical environment on thermal cis to trans relaxation is small; with relaxation rates in PMMA beeing  400) than the rates of esterified systems. This difference is a clear result of the different substituents on the azobenzene moiety. Quantum chemical calculations suggest that the cis-configuration in the esterified systems is stabilized by an intramolecular H-bond between a carbonyl oxygen on the substituent and an H atom on the phenyl ring. In all systems, the cis to trans isomerization can be significantly accelerated by illumination with 434 nm light. For esterified systems, accelerations by factors of about 5700 – 15500 are observed. In the case of 4-hydroxyazobenzene covalently bound (esterified) to the PMMA matrix, complete light induced transfer from cis to trans is possible. In addition, it features a low thermal cis to trans isomerization rate and acceptable photoinduced trans to cis isomerization properties. With this, the material fulfills the basic requirements of a functional polymer material whose properties can be reversibly changed by illumination with light.},
     year = {2014}
    }
    

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  • TY  - JOUR
    T1  - Optical Switching of Azophenol Derivatives in Solution and in Polymer Thin Films: The Role of Chemical Substitution and Environment
    AU  - Yasser M. Riyad
    AU  - Sergej Naumov
    AU  - Jan Griebel
    AU  - Christian Elsner
    AU  - Ralf Hermann
    AU  - Katrin R. Siefermann
    AU  - Bernd Abel
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    DO  - 10.11648/j.nano.s.2014020601.16
    T2  - American Journal of Nano Research and Applications
    JF  - American Journal of Nano Research and Applications
    JO  - American Journal of Nano Research and Applications
    SP  - 39
    EP  - 52
    PB  - Science Publishing Group
    SN  - 2575-3738
    UR  - https://doi.org/10.11648/j.nano.s.2014020601.16
    AB  - Design of polymer materials whose properties can be reversibly changed by illumination with light is a technology of particular scientific interest. Such materials contain molecular chromophors, which change their geometry and/or polarity upon absorption of light of a specific wavelength. The most prominent chromophores are azobenzene derivatives. Here, we present a systematic study on azobenzene derivatives in order to quantify the impact of chemical substitution and chemical environment on the dynamics of light-induced trans-cis isomerization (at 368 nm and 355 nm), thermal cis-trans relaxation, and light-induced cis-trans isomerization (at 434 nm). Systems under investigation were 4-hydroxyazobenzene (4-HAB) in acetonitrile (MeCN) solution and in a poly(methylmethacrylate) (PMMA) matrix. These two systems are compared to systems in which 4-HAB is esterified, namely 4-hydroxyazobenzene covalently bound (esterified) to PMMA matrix, and N-(tert-butoxycarbonyl)glycine-4- hydroxyazobenzene (Boc-Gly-4-HAB) in MeCN and in PMMA. Photoisomerization and thermal relaxation kinetics are monitored with UV-vis absorption spectroscopy and accompanied by quantum chemical calculations to shed light into the molecular origin of observed differences in switching properties. We find that the chemical environment (MeCN vs. PMMA) only has minor impacts (~10%) on trans to cis photoisomerization rates. Also, the impact of chemical environment on thermal cis to trans relaxation is small; with relaxation rates in PMMA beeing  400) than the rates of esterified systems. This difference is a clear result of the different substituents on the azobenzene moiety. Quantum chemical calculations suggest that the cis-configuration in the esterified systems is stabilized by an intramolecular H-bond between a carbonyl oxygen on the substituent and an H atom on the phenyl ring. In all systems, the cis to trans isomerization can be significantly accelerated by illumination with 434 nm light. For esterified systems, accelerations by factors of about 5700 – 15500 are observed. In the case of 4-hydroxyazobenzene covalently bound (esterified) to the PMMA matrix, complete light induced transfer from cis to trans is possible. In addition, it features a low thermal cis to trans isomerization rate and acceptable photoinduced trans to cis isomerization properties. With this, the material fulfills the basic requirements of a functional polymer material whose properties can be reversibly changed by illumination with light.
    VL  - 2
    IS  - 6-1
    ER  - 

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