Molecular structure of azobenzene-containing systems from classical MD simulations

Azobenzene-containing side chain polymers [1,2] and molecular glasses based on propeller-like C3-symmetric azobenzene mesogenes [3] are investigated in classical molecular dynamics simulations. Two length scales are considered: (i) the molecular level with atomistic resolution, where reversible conformational changes of azobenzene chromophores upon light illumination lead to contractions/extensions of low amplitudes due to a limited size of mesogene groups, and (ii) the mesoscopic level, where light-induced molecular movements are observed over larger distances, comparable with the gyration radius of polymer chains. The influence of isomerization and orientation mechanisms on molecular structure and light-induced deformation is elucidated. [1] J. Ilnytskyi et al., J. Chem. Phys. 135, 044901 (2011). [2] M Saphiannikova et al., Proceedings of SPIE "Optical Materials and Biomaterials in Security and Defence Systems Technology X", 8901, 890138 (2013). [3] N.S. Jadavalli et al., Appl. Phys. Lett. 105, 051601 (2014).