Theoretical design and computational simulations of visible light driven azobenzene-based switches

Abstract

Visible light driven azobenzene-based photoisomerization materials are expected to have potential applications in the fields of biological probe and sensor systems, photosensitive cells, energy storage materials and so on. The relationships between electronic structures and switching performance of o -R-substituted 4,4-diacetami-doazobenzene derivatives (R=F, Cl, Br or I) were investigated by using both density functional theory (DFT) and reactive molecular dynamics simulations. DFT calculations demonstrated that substituted groups of F, Cl, Br and I rendered the planar azo trans geometries distorted in different degree, resulting in the dipole-allowed excitations in the region of visible light. Furthermore, reactive MD simulations were carried out to simulate the reversible processes of o -R-substituted 4,4-diacetamidoazobenzene derivatives (R=F, Cl, Br or I), and 46%–86% trans isomers were demonstrated to translate to cis ones, which is in agreement with the experimental data.