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Related Experiment Video

Updated: Jul 5, 2026

Light-driven Molecular Motors on Surfaces for Single Molecular Imaging
08:40

Light-driven Molecular Motors on Surfaces for Single Molecular Imaging

Published on: March 13, 2019

A pentiptycene-derived light-driven molecular brake.

Jye-Shane Yang1, Yao-Ting Huang, Jinn-Hsuan Ho

  • 1Department of Chemistry and Instrumentation Center, National Taiwan University, Taipei, Taiwan. jsyang@ntu.edu.tw

Organic Letters
|May 6, 2008
PubMed
Summary
This summary is machine-generated.

This study introduces a light-controlled molecular brake that operates at room temperature. This innovative device exhibits a significant 9-order-of-magnitude change in rotation speed between its active and inactive states.

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Area of Science:

  • Molecular machinery
  • Supramolecular chemistry
  • Photochemistry

Background:

  • Molecular rotors are essential components in molecular machines, enabling controlled motion.
  • Developing light-responsive molecular brakes is crucial for precise control over molecular dynamics.
  • Pentiptycene-based systems offer a robust scaffold for constructing complex molecular architectures.

Purpose of the Study:

  • To design and synthesize a novel room-temperature, light-driven molecular brake.
  • To investigate the photoisomerization behavior of the ethenyl spacer and its effect on the molecular brake's function.
  • To quantify the difference in rotation rates between the brake-on and brake-off states.

Main Methods:

  • Synthesis of a molecular brake comprising a pentiptycene rotator, a 3,5-dinitrophenyl brake unit, and an ethenyl photoisomerizable spacer.
  • Photochemical isomerization of the ethenyl spacer using light to switch between cis and trans states.
  • Variable temperature studies to assess the performance of the molecular brake at room temperature.
  • Spectroscopic techniques to confirm the structural changes and monitor the isomerization process.

Main Results:

  • Successful synthesis of the light-driven molecular brake (1).
  • Demonstration of light-induced switching between the brake-on (cis-1) and brake-off (trans-1) states.
  • Observation of a dramatic difference in rotation rates, spanning approximately 9 orders of magnitude, between the two states.
  • Confirmation of room-temperature operation for the molecular brake.

Conclusions:

  • A functional room-temperature molecular brake controlled by light has been developed.
  • The molecular brake exhibits significant switching capabilities, enabling precise control over molecular rotation.
  • This work paves the way for advanced applications in molecular devices and nanotechnology.