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Updated: Jun 6, 2025
08:40
Light-driven Molecular Motors on Surfaces for Single Molecular Imaging
Published on: March 13, 2019
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Quantum-Classical Simulations Reveal the Photoisomerization Mechanism of a Prototypical First-Generation Molecular
Davide Accomasso1, Joanna Jankowska1
1Faculty of Chemistry, University of Warsaw, Pasteura 1, Warsaw, Poland.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|November 30, 2024
Summary
Light-driven molecular rotary motors use light energy for rotation. This study reveals how photoisomerization in alkene-based motors, driven by specific ground-state topography, leads to efficient forward motion.
Area of Science:
- Molecular machines
- Photochemistry
- Organic chemistry
Background:
- Light-driven molecular rotary motors are crucial for molecular machines.
- Chiral overcrowded alkenes are archetypal motors, using cis-trans photoisomerization and thermal helix inversion.
- Understanding photoisomerization mechanisms is key to improving motor efficiency.
Purpose of the Study:
- Investigate the excited-state decay and photoisomerization mechanism in a model alkene-based rotary motor.
- Elucidate the factors governing the operational efficiency of these molecular motors.
Main Methods:
- Quantum-chemical calculations
- Nonadiabatic molecular dynamics simulations
Main Results:
- The excited state rapidly relaxes to multiple minima.
- Ground-state decay occurs slowly from a twisted dark state, distant from conical intersections.
- High forward photoisomerization yields are linked to favorable ground-state potential energy surface topography.
Conclusions:
- The study clarifies the excited-state decay pathway in alkene-based rotary motors.
- Ground-state surface topography, influenced by cyclopentene ring conformation, dictates efficient forward photoisomerization.
- This work provides insights into optimizing molecular motor design and efficiency.
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