Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group

Einat Tirosh, Enrico Benassi, Silvio Pipolo, Marcel Mayor, Michal Valásek, Veronica Frydman, Stefano Corni, Sidney R. Cohen

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)834-844
Number of pages11
JournalBeilstein Journal of Nanotechnology
Volume2
Issue number1
DOIs
Publication statusPublished - 1 Dec 2011
Externally publishedYes

Fingerprint

Azobenzene
Self assembled monolayers
Isomerization
isomerization
Molecules
Monitoring
modulus of elasticity
Elastic moduli
atomic force microscopy
harmonics
molecules
optical switching
chemical bonds
Computational methods
Isomers
quantitative analysis
Molecular dynamics
manipulators
Atomic force microscopy
isomers

Keywords

  • AFM
  • Azobenzene
  • Elastic modulus
  • Molecular dynamics
  • Nanomechanics
  • Photoswitch
  • Quantum mechanics computation
  • Self-assembled monolayer

ASJC Scopus subject areas

  • Materials Science(all)
  • Physics and Astronomy(all)
  • Electrical and Electronic Engineering

Cite this

Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group. / Tirosh, Einat; Benassi, Enrico; Pipolo, Silvio; Mayor, Marcel; Valásek, Michal; Frydman, Veronica; Corni, Stefano; Cohen, Sidney R.

In: Beilstein Journal of Nanotechnology, Vol. 2, No. 1, 01.12.2011, p. 834-844.

Research output: Contribution to journalArticle

Tirosh, Einat ; Benassi, Enrico ; Pipolo, Silvio ; Mayor, Marcel ; Valásek, Michal ; Frydman, Veronica ; Corni, Stefano ; Cohen, Sidney R. / Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group. In: Beilstein Journal of Nanotechnology. 2011 ; Vol. 2, No. 1. pp. 834-844.
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