Vibrational wavepacket dynamics in Fe carbene photosensitizer determined with femtosecond X-ray emission and scattering

Research output: Contribution to journalJournal articleResearchpeer-review

  • Kristjan Kunnus
  • Morgane Vacher
  • Tobias C B Harlang
  • Kasper S Kjær
  • Kristoffer Haldrup
  • Elisa Biasin
  • Tim B van Driel
  • Mátyás Pápai
  • Pavel Chabera
  • Yizhu Liu
  • Hideyuki Tatsuno
  • Cornelia Timm
  • Erik Källman
  • Mickaël Delcey
  • Robert W Hartsock
  • Marco E Reinhard
  • Sergey Koroidov
  • Mads G Laursen
  • Frederik B Hansen
  • Peter Vester
  • Morten Christensen
  • Zoltán Németh
  • Dorottya Sárosiné Szemes
  • Éva Bajnóczi
  • Roberto Alonso-Mori
  • James M Glownia
  • Silke Nelson
  • Marcin Sikorski
  • Dimosthenis Sokaras
  • Henrik T Lemke
  • Sophie E Canton
  • Klaus B Møller
  • Martin M Nielsen
  • György Vankó
  • Kenneth Wärnmark
  • Villy Sundström
  • Petter Persson
  • Marcus Lundberg
  • Jens Uhlig
  • Kelly J Gaffney

The non-equilibrium dynamics of electrons and nuclei govern the function of photoactive materials. Disentangling these dynamics remains a critical goal for understanding photoactive materials. Here we investigate the photoinduced dynamics of the [Fe(bmip)2]2+ photosensitizer, where bmip = 2,6-bis(3-methyl-imidazole-1-ylidine)-pyridine, with simultaneous femtosecond-resolution Fe Kα and Kβ X-ray emission spectroscopy (XES) and X-ray solution scattering (XSS). This measurement shows temporal oscillations in the XES and XSS difference signals with the same 278 fs period oscillation. These oscillations originate from an Fe-ligand stretching vibrational wavepacket on a triplet metal-centered (3MC) excited state surface. This 3MC state is populated with a 110 fs time constant by 40% of the excited molecules while the rest relax to a 3MLCT excited state. The sensitivity of the Kα XES to molecular structure results from a 0.7% average Fe-ligand bond length shift between the 1 s and 2p core-ionized states surfaces.

Original languageEnglish
Article number634
JournalNature Communications
Volume11
Issue number1
Number of pages11
ISSN2041-1723
DOIs
Publication statusPublished - 31 Jan 2020

ID: 243197672