Time-resolved Core Level Photoemission in the Near-interfacial Region of Liquid Jets
Abstract
This proposal outlines a novel approach to performing femtosecond time-resolved investigations of chemical dynamics in liquids, particularly the near-interfacial region of a liquid surface. The work proposed here is motivated by studies showing that chemistry at the interface of a liquid solution can differ markedly from that in a bulk liquid or in the gas phase TIme-resolved photoelectron spectroscopy (TRPES) on flat liquid microjets will be carried out using femtosecond soft x-ray pulses at photon energies as high as 250 eV. These energies are sufficient to eject core electrons from phosphorous, sulfur, and halogen atoms, and the primary goal is to observe time-resolved core level chemical shifts in these atoms as a molecule undergoes photo- or electron-induced dissociation. Depending on the photon energy, the escape depth of the photoelectrons can be varied from 1-3 nm, enabling one to probe molecules within the interfacial region of the surface (roughly defined as 1 nm in depth) as well as deeper into the bulk liquid. Specific experiments of fundamental interest include the photophysics of thiouracil and the dynamics of dissociative electron attachment to bromouracil (BrU). These experiments will provide the foundation for studying molecules of interest to ARO, specifically the photochemistry and electron-driven reduction chemistry of the chemical warfare simulants malathion, parathion, and diphenyl chlorophosphate (DPCP). Overall, this proposal combines two recent ARO thrust areas, ultrafast x-ray science and interfacial chemistry, with the goal of addressing a new ARO area of interest in the Reactive Chemical Systems program, chemical reactivity at surfaces and interfaces with application to CW simulants.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 17, 2022
- Source ID
- W911NF2310003
Entities
People
- Daniel Neumark
Organizations
- Army Contracting Command
- United States Army
- University of California, Berkeley