************OWARI COMPLEX SEMINAR LXXI*************

Title：QTAIM and Stress tensor Characterization of 
       Intramolecular Interactions Along Dynamics 
       Trajectories of a Light-Driven Rotary 
       Molecular Motor

Speaker：Prof. Samantha Jenkins

Affiliation：Human Normal University

Date：Wed. Feb. 22nd, 3:30 pm (Almost one hour)

Place：Lecture Room 2 (1F) 
       Graduate School of Information Science

Abstract：
A QTAIM and stress tensor analysis was applied to 
analyze intramolecular interactions influencing 
the photoisomerization dynamics of a light-driven 
rotary molecular motor. For selected non-adiabatic 
molecular dynamics trajectories characterized by 
markedly different S1 state lifetimes the electron 
densities were obtained using the ensemble density 
functional theory method. The analysis revealed 
that torsional motion of the molecular motor 
blades from the Franck-Condon point to the S1 
energy minimum and the S1/S0 conical intersection 
is controlled by the presence of unusually 
strongly coupled intramolecular bond critical 
points and bond-paths between the atoms of the 
rotor and the stator blades. This results in the 
effective stalling of the progress along the 
torsional path for an extended period of time. 
This finding suggests a possibility of chemical 
tuning of the speed of photoisomerization of 
molecular motors and related molecular switches 
by reshaping their molecular backbones to decrease 
or increase the degree of coupling and numbers of 
intramolecular bond critical points as revealed by 
the QTAIM/stress tensor analysis of the electron 
density. Additionally, the stress tensor scalar 
and vector analysis was found to provide new 
methods to follow the trajectories and from this 
new insight was gained into the behavior of the 
S1 state in the vicinity of the conical 
intersection.


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