skip to main content


This content will become publicly available on November 3, 2018

Title: Electronic and Structural Dynamics During the Switching of the Photomagnetic Complex [Fe(L 222N 5)(CN) 2]

The [Fe(L 222N 5)(CN) 2] compound, where L 222N 5 refers to the macrocyclic Schiff-base ligand, 2,13-dimethyl-3,6,9,-12,18-pentaazabicyclo[12.3.1]octadeca-1(18),2,12,14,- 16-pentaene, is a photomagnetic Fe II based coordination compound, which undergoes light-induced excited spin-state trapping (LIESST). The low spin state is hexacoordinated and the high spin state heptacoordinated. This system also serves as complex for the design of trinuclear or one-dimensional compounds made of other types of bricks with diverse coordinated metals. In this work, its ultrafast spin-state photoswitching dynamics are studied, by combining femtosecond optical spectroscopy and femtosecond X-ray absorption measurements at the XPP station of the X-ray free-electron laser LCLS. DFT and TD-DFT calculations are used to interpret experimental findings. These studies, performed in the solution phase, show that LIESST in [Fe(L 222N 5)(CN) 2] occurs on the 100 fs timescale under different types of photoexcitation. In addition, coherent oscillations were observed, resulting from the structural dynamics accompanying LIESST, which were recently evidenced in more conventional octahedral Fe IIN 6 systems.
 [1] ; ORCiD logo [1] ;  [1] ; ORCiD logo [2] ;  [3] ;  [3] ;  [3] ;  [4] ;  [4] ;  [5] ;  [1] ; ORCiD logo [1]
  1. Univ. of Rennes, UR1-CNRS, UMR 6251 (France). Inst. of Physics of Rennes
  2. Univ. of Bordeaux, CNRS, ICMCB, Pessac (France); Lebanese German Univ. (LGU), Jounieh (Lebanon)
  3. Univ. of Bordeaux, CNRS, ICMCB, Pessac (France)
  4. SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS)
  5. SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS); Paul Scherrer Inst. (PSI), Villigen (Switzerland). SwissFEL
Publication Date:
Grant/Contract Number:
AC02-76SF00515; ANR-13-BS04-0002 FEMTOMAT; ANR-15-CE32-0004 BioXFEL; PEPS SASLELX; ARED 8925/XFELMAT
Accepted Manuscript
Journal Name:
Chemistry - A European Journal
Additional Journal Information:
Journal Volume: 24; Journal Issue: 20; Journal ID: ISSN 0947-6539
ChemPubSoc Europe
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); French National Research Agency (ANR); French National Center for Scientific Research (CNRS); Brittany Region (France). Doctoral Research Allowances (ARED)
Country of Publication:
United States
36 MATERIALS SCIENCE; 74 ATOMIC AND MOLECULAR PHYSICS; intersystem crossing; LIESST; spin crossover; time-resolved spectroscopy; X-ray absorption spectroscopy
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1410596