A flexible molecular motor was first developed in 1999, in the laboratory of Ben Feringa, professor of organic chemistry at the University of Groningen. These motors are powered by electricity. For many reasons, it would be good to be able to make these things visible. The best way to do this is to make them fluorescent. However, combining two light-emitting functions in one molecule is difficult. Feringa Lab has been able to do this in two different ways. Both types of fluorescent light (A molecular motor that produces light) bulbs have been described in Nature Communications (September 30) and Science Advances (November 4).
Feringa, who shared the 2016 Nobel Prize in Chemistry, said, “After the successful development of motors in the past decades, another important goal is to manage different functions and materials. “Because these are variable motors that work with electricity, it is difficult to create a system (A molecular motor that produces light) that will have any other function that is controlled by electricity, in addition to the rotation.”
Break
Feringa and his team are particularly interested in fluorescence since it is the method of choice that is often used for detection, for example in medical imaging. Usually two such photochemical actions do not correspond to the same molecule; or the motor is burning and running but nothing is shining, or there is fluorescence and the motor is not running. Feringa: “Now we have shown (A molecular motor that produces light) that these two functions can coexist in the same molecular system, which is unique.”
Ryojun Toyoda, a postdoctoral researcher in the Feringa group, who now holds a professorship at Tohoku University in Japan, added a light source to Feringa’s rotary motor. “The trick is to prevent these two strategies from interfering with each other,” Toyoda says. He managed to prevent the relationship between paint and engine. This is done by applying the cleaner to the surface of the metal to which it is applied. “It hinders relationships,” says Toyoda.
Application
In this way, the fluorescence and the rotary function of the motor can coexist. Also, he turned out that changing the solvent allows him to repeat the process: “By changing the polarity of the solvent, the balance between the two functions can be changed.” This means that the engine has had an effect on its environment, which may indicate the way for future applications.
Different colors
Co-author Shirin Faraji, a professor of chemistry at the University of Groningen, helped explain how this happens. Kiana Moghaddam, a postdoc in his group, performed a series of experiments and showed how the strength of the photo-exciters depends on the polarity of the solvent. Another useful property of this fluorescent motor is that it can be installed in different layers as long as they have a similar structure. “So it’s easy to make engines that glow in different colors,” says Toyoda.
Antenna
Lukas Pfeifer built the second fluorescent engine, and works as a postdoctoral researcher in the Feringa group. He has joined the Ecole Polytechnique Fédérale in Lausanne, Switzerland: “My solution is based on a molecular motor that I have already made, driven by two low-energy photons.” light is useful in biology because this light penetrates the body more than visible light and is less harmful to the body than UV light.
“I added an antenna to the motor molecule that collects energy from two infrared photons and transmits it to the motor. Working on this, we discovered that with some modifications, the antenna can also cause fluorescence”, Pfeifer is explain. It turns out that the molecule can have two different excited states: in one state, energy is transferred to the motor part and drives rotation, while the other state makes the molecule glow.
Wave action
“In the case of this second motor, the whole molecule becomes fluorescent,” says Prof. Maxim Pshenichnikov explains, who conducted a spectroscopic analysis of two types of fluorescent motors and approved the two papers. “This motor is a chemical that does not work waves and, depending on the power level, can have two different effects. By changing the wavelength of the light, and therefore the energy that the molecule receives, you will get fluorescence or fluorescence.” the center of study and research, and demonstrates the power of all combined efforts.
Now that the group has combined movement and fluorescence in the same molecule, the next step will be to show the motility and at the same time determine the location of the molecule by detecting fluorescence. Feringa: “It is so powerful that we can apply it to show how these motors can pass through the cell membrane or enter the cell, because fluorescence is a method that is often used to show the location of the motor exist.molecules in the cell. We can also use it to model the motion of a light-emitting motor, for example along a nanoscale trajectory or perhaps to plot transport at the nanoscale. This is all part of the evaluation process.
