Photodissociation of aqueous [Formula: see text] observed with liquid-phase ultrafast mega-electron-volt electron diffraction

K Ledbetter; E Biasin; J P F Nunes; M Centurion; K J Gaffney; M Kozina; M-F Lin; X Shen; J Yang; X J Wang; T J A Wolf; A A Cordones

doi:10.1063/4.0000051

Photodissociation of aqueous $I_{3}^{-}$ observed with liquid-phase ultrafast mega-electron-volt electron diffraction

Struct Dyn. 2020 Dec 28;7(6):064901. doi: 10.1063/4.0000051. eCollection 2020 Nov.

Authors

K Ledbetter, E Biasin¹, J P F Nunes², M Centurion², K J Gaffney¹, M Kozina³, M-F Lin³, X Shen³, J Yang, X J Wang³, T J A Wolf¹, A A Cordones¹

Affiliations

¹ Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
² Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.
³ SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.

Abstract

Developing femtosecond resolution methods for directly observing structural dynamics is critical to understanding complex photochemical reaction mechanisms in solution. We have used two recent developments, ultrafast mega-electron-volt electron sources and vacuum compatible sub-micron thick liquid sheet jets, to enable liquid-phase ultrafast electron diffraction (LUED). We have demonstrated the viability of LUED by investigating the photodissociation of tri-iodide initiated with a 400 nm laser pulse. This has enabled the average speed of the bond expansion to be measured during the first 750 fs of dissociation and the geminate recombination to be directly captured on the picosecond time scale.