Dynamic simulations of stimuli-responsive switching of azobenzene derivatives in self-assembled monolayers: reactive rotation potential and switching functions

Abstract

Although the force field (FF)-based molecular dynamics (MD) simulation has been widely applied to rationalise the experimental observations and measurements in chemistry, physics, materials and life science for years, traditional FF suffers from the incapability for describing chemical reactions, which are crucial in many important transformation processes. In order to simulate the collective switching process in azobenzene-based self-assemble monolayers on Au(111) surface, reactive MD simulations with alternative FF were implemented. The classic torsion function has been modified to depict the diabatic potential energy curves for cis and trans isomers, respectively. A switching function is further introduced to connect two N = N rotation functions, and the surface hopping between the cis and trans curves is allowed. By using the reactive rotation potential and switching function, the collective effect of numerous reaction centres and the influence of environment on the quantum yield in the complex system were explored at mesoscopic dimension and timescales. The reactive FF may be also applicable for other complicated systems containing stilbene derivatives. Limitation and perspective for further developments for the other complicated reactions are also addressed.