Molecular HopScotch increases the ascending conversion of light

A new molecule that allows energy to quickly jump into its structure causes the recycling of light to be more efficient and tuneable. The development of the University of Kobe establishes a design strategy for a better use of solar energy, as well as medical and sensor applications.

While low energy is abundant and harmless, many technical applications from solar energy generation to medical treatments depend on high energy light. To increase the efficiency of light collection and avoid high energy light as much as possible in treatment technologies, it is possible to merge two low energy particles in a single high -energy particle in a process called “ascending conversion.”

However, this requires two molecules that have absorbed a light particle to stop with each other in the correct orientation, and the researchers are still sizes for a frame to improve and control this process.

The photocientific of the University of Kobe, Kobori Yasuhiro, has been studying the opposite process, an energized molecule that transfers half of its excitation energy to another molecule, and says: “We have established an analytical method to clarify how the absorbed energy transforms the molecule and how it moves, and I think this can be useful when they try to achieve the uponversion.”

In principle, there are two ways to make it more likely that excitation energy jump from one molecule to the other, that is, either allowing the molecules to stop with each other more frequently, reducing the viscosity of the medium or increasing the area over which the reaction can occur. But there is a fluid limit can be a medium, and a larger reaction area often means that the energy that can be transferred effectively will be lower.

In the newspaper ANGEWANDTE CHEMIE INTERNATIONAL EDITIONKobori and his team report that have created a molecule that allows a faster energy fusion rate of 20% than with previous materials.

“We use three anthracen molecules that are arranged as antennas in three different directions around a central boron atom. This allows the excited state, which we call a ‘triplet exciton’, to quickly jump around the three anthraceans and essentially allows you to try a larger space and multiple configurations without losing its energy,” explains Kobori.

The jump is so fast, in fact, that it is faster than the usual duration of a molecular collision, which makes it very likely that the excited triplet states are oriented and the energy fusion process called “triplet triplet annihilation” can take place.

When studying the mechanics of how this process occurs, researchers from the University of Kobe made another discovery. They discovered that they can control the luminescence by changing the viscosity of the medium, because the most viscous materials reduce both the encounter between the molecules and the capacity of the triplet state excited to jump between parts of a molecule.

Kobori says: “We believe that with this, it could be possible to trace the fluid environment in the microscopic regions, for example, within the cells.”

What Kobori and his team found is not only a better molecular configuration, but a molecular design strategy. They hope that the incorporation of such an intramolecular perspective can advance in the development of high efficiency ascending converters.

Kobori says: “We hope that this development can contribute to solving global energy problems, as well as to expand to a wide range of fields, such as the therapy and diagnosis of cancer, through the use of the harmless light of low energy and the ascending conversion in situ.”