Publication Date:
2014-05-09
Description:
Crucial to many light-driven processes in transition metal complexes is the absorption and dissipation of energy by 3d electrons. But a detailed understanding of such non-equilibrium excited-state dynamics and their interplay with structural changes is challenging: a multitude of excited states and possible transitions result in phenomena too complex to unravel when faced with the indirect sensitivity of optical spectroscopy to spin dynamics and the flux limitations of ultrafast X-ray sources. Such a situation exists for archetypal polypyridyl iron complexes, such as [Fe(2,2'-bipyridine)3](2+), where the excited-state charge and spin dynamics involved in the transition from a low- to a high-spin state (spin crossover) have long been a source of interest and controversy. Here we demonstrate that femtosecond resolution X-ray fluorescence spectroscopy, with its sensitivity to spin state, can elucidate the spin crossover dynamics of [Fe(2,2'-bipyridine)3](2+) on photoinduced metal-to-ligand charge transfer excitation. We are able to track the charge and spin dynamics, and establish the critical role of intermediate spin states in the crossover mechanism. We anticipate that these capabilities will make our method a valuable tool for mapping in unprecedented detail the fundamental electronic excited-state dynamics that underpin many useful light-triggered molecular phenomena involving 3d transition metal complexes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Wenkai -- Alonso-Mori, Roberto -- Bergmann, Uwe -- Bressler, Christian -- Chollet, Matthieu -- Galler, Andreas -- Gawelda, Wojciech -- Hadt, Ryan G -- Hartsock, Robert W -- Kroll, Thomas -- Kjaer, Kasper S -- Kubicek, Katharina -- Lemke, Henrik T -- Liang, Huiyang W -- Meyer, Drew A -- Nielsen, Martin M -- Purser, Carola -- Robinson, Joseph S -- Solomon, Edward I -- Sun, Zheng -- Sokaras, Dimosthenis -- van Driel, Tim B -- Vanko, Gyorgy -- Weng, Tsu-Chien -- Zhu, Diling -- Gaffney, Kelly J -- P41 GM103393/GM/NIGMS NIH HHS/ -- P41 RR001209/RR/NCRR NIH HHS/ -- England -- Nature. 2014 May 15;509(7500):345-8. doi: 10.1038/nature13252. Epub 2014 May 7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA. ; LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA. ; European XFEL, D-22761 Hamburg, Germany. ; Department of Chemistry, Stanford University, Stanford, California 94305, USA. ; 1] PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA [2] Department of Chemistry, Stanford University, Stanford, California 94305, USA. ; 1] Centre for Molecular Movies, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark [2] Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark. ; 1] Max Planck Institute for Biophysical Chemistry, 37077 Gottingen, Germany [2] Deutsches Elektronen Synchrotron, Notkestrasse 85, 22607 Hamburg, Germany. ; Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark. ; 1] Department of Chemistry, Stanford University, Stanford, California 94305, USA [2] SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA. ; SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA. ; Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1525 Budapest, Hungary.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24805234" target="_blank"〉PubMed〈/a〉
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
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Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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