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Dan Neumark

Probing interfacial dynamics in liquids by time-resolved photoelectron spectroscopy and molecular beam scattering

Wed, Feb. 28, 2024, 4:30pm
Taylor Auditorium, Frick Chemistry Lab B02
Host: SILS

Two new experimental directions in our group based on flat liquid jet spectroscopy and scattering will be described.  The dynamics of photoexcited nucleic acid constituents in water are probed using time-resolved photoelectron spectroscopy with a femtosecond  extreme ultraviolet (22 eV) ionization pulse.  We find that the initially excited pp* state in adenine and its derivatives decays to the ground state in about 100 fs, and that the optically dark np* state also plays a role in the overall relaxation mechanism.  Molecular beam scattering experiments from a flat jet of dodecane and, more recently, cold salty water provide a microscopic probe of the interaction between gas molecules and a liquid surface, in particular whether an incoming gaseous species scatters from the surface or dissolves and then evaporates.