Trans-cis photoisomerization of azobenzene by n → π* excitation: A semiclassical dynamics study

A realistic dynamics simulation study is reported for the trans-cis photoisomerization of azobenzene triggered by the n → π* excitation and the results show that the formation of cis isomer follows the rotational motion around the NN bond. The simulation find that the CNN bond angle bending vibrations also play a significant role in the vibronic coupling between the HOMO and LUMO, which essentially leads a nonadiabatic transition of the molecule to the electronic ground state.