Describe the structural changes during the 4-step unidirectional isomerization of a first-generation aldehyde motor, with key features located above the reaction arrow. Starting from the upper left corner, UV-induced photoisomerization reaches the upper right state with an efficiency of over 95%. This state in the upper right corner is transformed through a one-way thermal “spiral inversion” step (THI) to the state shown in the lower right corner, completing half a cycle of rotation.Subsequent UV irradiation will result in the state shown below left (efficiency over 80%), which can be converted to the initial state of the motor through another unidirectional THI step, completing a 360-degree rotationoh rotation period.Image credit: J. Shen et al., University of Groningen
Nearly 25 years ago, the University of Groningen in the Netherlands first developed a light-driven molecular motor. Professor Ben Feringa won the 2016 Nobel Prize in Chemistry. A new paper from Feringa’s lab is published in natural chemistry On April 26, a series of improvements were described to bring real-life applications closer.
The first author Jin Yusheng is currently a postdoctoral researcher at the Institute of Science and Technology Austria (ISTA). He transformed the “first generation” light-driven molecular motor during his PhD studies. Research in Feringa’s laboratory. His main focus was on improving the efficiency of moving molecules. “It’s very fast, but only 2% of the photons absorbed by the molecule drive rotational motion.”
This inefficiency may hinder real-life applications. “In addition, increasing efficiency will allow us to better control movement,” Sheng added. The rotational motion of Feringa’s molecular motor occurs in four steps: two of them are photochemical and the other two are temperature-driven. The latter is unidirectional, but the photochemical step leads to molecular isomerization, which is often reversible.
Sheng set out to increase the percentage of absorbed photons that drive rotational motion. “It was difficult to predict how to do this, and in the end, we unexpectedly discovered a method that works.” Sheng added aldehyde functional groups to the motor molecules as a first step toward further transformations.
“However, I decided to test the motion capabilities of this intermediate version and found that it works very well in a way we’ve never seen before.”
To this end, he collaborates with the Molecular Photonics Group at the Van’t Hof Institute of Molecular Sciences at the University of Amsterdam. Using advanced laser spectroscopy and quantum chemical calculations, electron decay paths were mapped, providing detailed insights into the workings of molecular motors.
Optical image of improved motor molecules in liquid crystal cells. The RUG letters are created by exposure to ultraviolet light through a mask, moving molecules into positions that make the liquid crystal appear green. The masked area shows no color change, but the right side is a bit green due to irregular cell thickness. Image credit: J. Shen et al., University of Groningen/Nature Chemistry
Furthermore, it became clear that this adaptation did give Sheng greater control over the rotational motion of the molecule. As mentioned previously, molecular motors rotate in four discrete steps. “Previously, if we illuminated a batch of motors with light, we would get a mixture of motors at different stages of the rotation cycle. With the modification, it is possible to synchronize all the motors and control them at each stage,” Sheng said.
This opens up all kinds of possibilities. For example, motors can be used as chiral dopants in liquid crystals, where different locations produce different reflection colors. In the paper, Sheng and his colleagues gave an example. For example, other applications could be the control of molecular self-assembly.
Adding an aldehyde group to the motor molecule has another interesting effect: it shifts the absorption of light to longer wavelengths. Since longer wavelengths can further penetrate living tissue or bulk materials, this means that motors can work more efficiently in medical applications and materials science because more light will reach the motor molecules, which will also be more efficient. Use photons.
“Many of our colleagues are now working with us to develop this new molecular motor for different applications,” Sheng said. He anticipates more papers on this topic in the near future. Meanwhile, Ferlinga’s lab faces another challenge. “The molecular motors are now more efficient, but we don’t know exactly why the modification causes this effect. We are currently studying it.”
More information:
Jinyu Shen et al., Formylation improves the performance of light-driven overcrowded olefin-derived rotary molecular motors, natural chemistry (2024). DOI: 10.1038/s41557-024-01521-0
Provided by University of Groningen
citation: More efficient molecular motors broaden potential applications (2024, April 26), Retrieved April 26, 2024, from https://phys.org/news/2024-04-efficient-molecular-motor-widens – pottial.html
This document is protected by copyright. No part may be reproduced without written permission except in the interests of fair dealing for private study or research purposes. Content is for reference only.
#efficient #molecular #motors #broaden #potential #applications
Image Source : phys.org