First-principles simulation of the photoreaction of a capped azobenzene: the rotational pathway is feasible.

We present first-principles molecular dynamics simulations of azobenzene and a sterically hindered derivative in the first excited state. The restricted open-shell Kohn-Sham (ROKS) approach is employed to describe the motion in the lowest excited state. The rotational pathway is observed in the molecular dynamics simulations for both azobenzene and its azacrown ether capped derivative.