Stimuli Thresholds for Isomerization-Induced Molecular Motions in Azobenzene-Containing Materials

• Published in: The journal of physical chemistry. B Vol. 119; no. 9; pp. 3854 - 3859
• Main Author: Teboul, V
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 05.03.2015
• Subjects: Physics
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp511494v

We use large-scale molecular dynamics simulations of the isomerizations of azobenzene molecules diluted inside a simple molecular material to investigate the effect of a modification of the cis isomer shape on the induced diffusion mechanism. To this end we simulate incomplete isomerizations, modifying the amplitude of the trans-to-cis isomerization. We find thresholds in the evolution of the host molecules mobility with the isomerization amplitude, a result predicted by the cage-breaking mechanism hypothesis (Teboul, V.; Saiddine, M.; Nunzi, J. M.; Accary, J. B. J. Chem. Phys. 2011, 134, 114517) and by the gradient pressure mechanism theory (Barrett, C. J.; Rochon, P. L.; Natansohn, A. L. J. Chem. Phys. 1998, 109, 1505–1516.). Above the threshold the diffusion then increases linearly with the variation of the chromophore size induced by the isomerization.