Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group
The potential for manipulation and control inherent in molecule-based motors holds great scientific and technological promise. Molecules containing the azobenzene group have been heavily studied in this context. While the effects of the cis–trans isomerization of the azo group in such molecules have...
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| Format: | Article |
| Language: | English |
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Beilstein-Institut
2011-12-01
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| Series: | Beilstein Journal of Nanotechnology |
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| Online Access: | https://doi.org/10.3762/bjnano.2.93 |
| _version_ | 1818315874318155776 |
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| author | Einat Tirosh Enrico Benassi Silvio Pipolo Marcel Mayor Michal Valášek Veronica Frydman Stefano Corni Sidney R. Cohen |
| author_facet | Einat Tirosh Enrico Benassi Silvio Pipolo Marcel Mayor Michal Valášek Veronica Frydman Stefano Corni Sidney R. Cohen |
| author_sort | Einat Tirosh |
| collection | DOAJ |
| description | The potential for manipulation and control inherent in molecule-based motors holds great scientific and technological promise. Molecules containing the azobenzene group have been heavily studied in this context. While the effects of the cis–trans isomerization of the azo group in such molecules have been examined macroscopically by a number of techniques, modulations of the elastic modulus upon isomerization in self-assembled films were not yet measured directly. Here, we examine the mechanical response upon optical switching of bis[(1,1'-biphenyl)-4-yl]diazene organized in a self-assembled film on Au islands, using atomic force microscopy. Analysis of higher harmonics by means of a torsional harmonic cantilever allowed real-time extraction of mechanical data. Quantitative analysis of elastic modulus maps obtained simultaneously with topographic images show that the modulus of the cis-form is approximately twice that of the trans-isomer. Quantum mechanical and molecular dynamics studies show good agreement with this experimental result, and indicate that the stiffer response in the cis-form comprises contributions both from the individual molecular bonds and from intermolecular interactions in the film. These results demonstrate the power and insights gained from cutting-edge AFM technologies, and advanced computational methods. |
| first_indexed | 2024-12-13T09:12:28Z |
| format | Article |
| id | doaj.art-f2faf94f799343e5a6ae6e825a18b3f0 |
| institution | Directory Open Access Journal |
| issn | 2190-4286 |
| language | English |
| last_indexed | 2024-12-13T09:12:28Z |
| publishDate | 2011-12-01 |
| publisher | Beilstein-Institut |
| record_format | Article |
| series | Beilstein Journal of Nanotechnology |
| spelling | doaj.art-f2faf94f799343e5a6ae6e825a18b3f02022-12-21T23:52:55ZengBeilstein-InstitutBeilstein Journal of Nanotechnology2190-42862011-12-012183484410.3762/bjnano.2.932190-4286-2-93Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene groupEinat Tirosh0Enrico Benassi1Silvio Pipolo2Marcel Mayor3Michal Valášek4Veronica Frydman5Stefano Corni6Sidney R. Cohen7Weizmann Institute of Science, Department of Materials and Interfaces, Rehovot IsraelCenter S3, CNR Institute of Nanoscience, Modena, ItalyCenter S3, CNR Institute of Nanoscience, Modena, ItalyKarlsruhe Institute of Technology, Institute of Nanotechnology, PO Box 3640, D-76021, Karlsruhe, GermanyKarlsruhe Institute of Technology, Institute of Nanotechnology, PO Box 3640, D-76021, Karlsruhe, GermanyWeizmann Institute of Science, Department of Chemical Research Support, Rehovot IsraelCenter S3, CNR Institute of Nanoscience, Modena, ItalyWeizmann Institute of Science, Department of Chemical Research Support, Rehovot IsraelThe potential for manipulation and control inherent in molecule-based motors holds great scientific and technological promise. Molecules containing the azobenzene group have been heavily studied in this context. While the effects of the cis–trans isomerization of the azo group in such molecules have been examined macroscopically by a number of techniques, modulations of the elastic modulus upon isomerization in self-assembled films were not yet measured directly. Here, we examine the mechanical response upon optical switching of bis[(1,1'-biphenyl)-4-yl]diazene organized in a self-assembled film on Au islands, using atomic force microscopy. Analysis of higher harmonics by means of a torsional harmonic cantilever allowed real-time extraction of mechanical data. Quantitative analysis of elastic modulus maps obtained simultaneously with topographic images show that the modulus of the cis-form is approximately twice that of the trans-isomer. Quantum mechanical and molecular dynamics studies show good agreement with this experimental result, and indicate that the stiffer response in the cis-form comprises contributions both from the individual molecular bonds and from intermolecular interactions in the film. These results demonstrate the power and insights gained from cutting-edge AFM technologies, and advanced computational methods.https://doi.org/10.3762/bjnano.2.93AFMazobenzeneelastic modulusmolecular dynamicsnanomechanicsphotoswitchquantum mechanics computationself-assembled monolayer |
| spellingShingle | Einat Tirosh Enrico Benassi Silvio Pipolo Marcel Mayor Michal Valášek Veronica Frydman Stefano Corni Sidney R. Cohen Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group Beilstein Journal of Nanotechnology AFM azobenzene elastic modulus molecular dynamics nanomechanics photoswitch quantum mechanics computation self-assembled monolayer |
| title | Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group |
| title_full | Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group |
| title_fullStr | Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group |
| title_full_unstemmed | Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group |
| title_short | Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group |
| title_sort | direct monitoring of opto mechanical switching of self assembled monolayer films containing the azobenzene group |
| topic | AFM azobenzene elastic modulus molecular dynamics nanomechanics photoswitch quantum mechanics computation self-assembled monolayer |
| url | https://doi.org/10.3762/bjnano.2.93 |
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