We demonstrate an experimental method to record snapshot diffraction images of polyatomic gas-phase molecules, which can, in a next step, be used to probe time-dependent changes in the molecular geometry during photochemical reactions with femtosecond temporal and angstrom spatial resolution. Adiabatically laser-aligned 1-ethynyl-4-fluorobenzene (C8H5F) molecules were imaged by diffraction of photoelectrons with kinetic energies between 31 and 62 eV, created from core ionization of the fluorine (1s) level by ≈80 fs x-ray free-electron-laser pulses. Comparison of the experimental photoelectron angular distributions with density functional theory calculations allows relating the diffraction images to the molecular structure.

Phys. Rev. A

Boll, R., Anielski, D., Bostedt, C., Bozek, J. D., Christensen, J., Coffee, R., … Rolles, D. (2013). Femtosecond photoelectron diffraction on laser-aligned molecules: Towards time-resolved imaging of molecular structure. Phys. Rev. A, 88(6, Article number: 61402), 1–5. doi:10.1103/PhysRevA.88.061402