Study shows how electrons move in a chemical reaction

Ottawa, ON – A revolutionary experiment conducted by the University of Ottawa and the National Research Council of Canada’s Joint Attosecond Science Laboratory (JASLab) to solve the mystery of how electrons move in a chemical reaction has been published in the journal Science.

The research produced unprecedented images of how the energy of light is processed in a molecule and showed how electrons move and rearrange as a chemical reaction proceeds.

The team of international scientists from Canada and France worked with nitrogen dioxide molecules (NO₂), which is an atmospheric pollutant. Using an intense femtosecond laser pulse, the scientists recorded the instances after the molecule was struck by the intense light.

The new approach, called high-harmonic spectroscopy, allowed the researchers to observe the NO₂ molecule until it began to shake and jiggle and eventually separated into a nitrogen oxide (NO) molecule and an oxygen atom.

This is a fundamental advance in the understanding of how molecules respond to light. The experiment mimics the mechanisms involved in vision, where light strikes a molecule and changes its shape, or in photosynthesis, where molecules transform the energy of light to make biomass from carbon dioxide (CO₂).

The discovery will contribute to the creation of lower-cost and lower-waste chemical processes and products, impact the light-controlled synthesis of molecules and lead to better solar cells. It also holds tremendous potential for the development of artificial photosynthesis.

The joint NRC-University of Ottawa research team included NRC Attosecond Science Program group leader David M Villeneuve and Herzberg medalist Paul Corkum, director of JASLab.