Séminaire de P. Bryan Changala, en mode hybride

Exotic molecules in the laboratory and space : Probing chemistry and electronic properties with high-resolution microwave spectroscopy

P. Bryan Changala

Center for Astrophysics | Harvard & Smithsonian Cambridge, Massachusetts

The key molecules that drive the chemical evolution of diverse environ-ments, from Earth’s atmosphere to circumstellar and interstellar space, are often highly reactive, short-lived species with exotic molecular structures and properties. A coordinated effort combining laboratory experiments, theoretical quantum chemistry, and observational astronomy is necessary to understand the formation and fate of these molecules in extreme astrophys-ical conditions. I will describe how we use microwave spectroscopy as a tool to sensitively detect and exhaustively characterize complex molecules ; in-terpret the chemical implications of these measurements with sophisticated ab initio electronic structure and quantum nuclear motion theory ; and use these data to search for evidence of new molecules in space with large radio telescopes. This joint approach has proved crucial to addressing the un-expectedly complex organic chemistry of polycyclic aromatic hydrocarbons recently revealed in the interstellar medium and new metal-organic chem-istry occuring in the outflows of evolved carbon-rich stars. Our experimental and theoretical results provide unique insights into molecular physics appli-cations more broadly, including laser-cooling of metal-organic polyatomic molecules, which highlights the impact of these methods in molecular quan-tum science at large.

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http://www.ismo.universite-paris-saclay.fr/spip.php?article2820