Next-generation quantum theory of atoms in molecules for the S-1/S-0 conical intersections in dynamics trajectories of a light-driven rotary molecular motor

Abstract

Next-generation quantum theory of atoms in molecules was applied to analyze, along an entire bond path, intramolecular interactions known to influence the photoisomerization dynamics of a light-driven rotary molecular motor. The 3D bond-path framework set B-0,B-1 constructed from the least and most preferred directions of electronic motion, provided new insights into the bonding leading to different S-1 state lifetimes including the first quantification of covalent character of a closed-shell intramolecular bond path. We undertook the first use of the stress tensor trajectory T-sigma(s) analysis on selected nonadiabatic molecular dynamics trajectories with the electron densities obtained using the ensemble density functional theory method. The stress tensor T-sigma(s) analysis was found to be well suited to follow the dynamics trajectories that included the S-0 and S-1 electronic states through the conical intersection and also provided to a new measure to assess the degree of purity of the axial bond rotation for the design of rotary molecular motors.