Unpicking the influence of structure and solvent on the photochemistry of deprotonated keto acids

Volatile organic compounds (VOCs) are molecules responsible for a large number of chemical reactions in our atmosphere. A specific class of VOCs known as keto acids is believed to be key contributors to the formation of secondary organic aerosols, which are directly linked to air pollution and global warming. The chemical reactivity of keto acids is triggered by them absorbing light from the sun. However, only little is known about the direct chemical reactions following light absorption, in particular when the keto acids may become negatively charge ('deprotonated') in the presence of water molecules. A recent study has shown that these deprotonated keto acids can form unexpected molecules upon light absorption. Our project proposes to investigate experimentally and theoretically the products formed after the deprotonated keto acids absorbed light, unravelling the different products these molecules can form - an information of great importance for atmospheric chemistry. In addition, we propose to investigate the influence that water, present in the atmosphere as droplets, can have on these light-triggered reactions of deprotonated keto acids. Detecting and investigating the formation of unexpected products from deprotonated keto acids, with or without the presence of water molecules, is of great importance to understand the formation of secondary organic aerosols and to complement the atmospheric models used to investigate air pollution and global warming.