The dance of electrons and protons is at the center of energy conversion. The steps to a new photo-chemical rhumba are said to have been learned by chemists at Yale and Sweden.
Insights into the way the natural world converts solar energy into fuel could be provided by the discovery. New solar energy technology and solar cells could be aided by that knowledge.
"Although it is rare to discover a new, fundamental type of mechanism, this molecular system was primed to reveal such intriguing behavior," said Sharon Hammes-Schiffer, the sterling professor of chemistry at Yale. Theory and experiment collaborated to make this work happen.
The co-corresponding authors of the study are James Mayer, a chemistry professor at Yale, and Leif Hammarstrm, a chemistry professor in Sweden.
The researchers found that certain molecule can show an effect called the Marcus inverted region when irradiated. As the reaction becomes more favorable, it slows down. Scientists say that the MIR effect is important to the efficiency of photosynthesis. They describe the MIR behavior as a PCET reaction.
Some of the molecule they studied did not show MIR. They thought there might be a different photochemical process at work. There is a competing mechanism in which electronic energy transfer and protons arecoupled.
That is what the team discovered in the new study.
In a series of photochemical experiments, the researchers dissolved the molecule in a glass that isolated the new mechanism. The team observed the new mechanism after illuminating the cold molecule with light.
The energy from photoexcitation in one fragment of a molecule is transferred to another fragment in the molecule. electron transfer between the two fragments is not involved in this energy transfer. The process is called PC EnT, which involves energy transfer.
It has been known for a long time that electronic energy transfers between parts of a molecule are important. The first example of photochemical energy transfer that is coupled to movement of an atom or a nucleus isPCEnT.
Zhentao and Rimgard are the co-first authors. A graduate student from Yale and a former Yale fellow are also authors.
More information: Belinda Pettersson Rimgard et al, Proton-coupled energy transfer in molecular triads, Science (2022). DOI: 10.1126/science.abq5173 Journal information: Science
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