Sub-50-fs photoinduced spin crossover in [fe(bpy)3]2+

ABSTRACT It is known that excitation by visible light of the singlet metal-to-ligand charge-transfer (1MLCT) states of Fe(II) complexes leads to population of the lowest-lying high-spin

quintet state (5T) with unity quantum yield. Here we investigate this so-called spin crossover (SCO) transition in aqueous iron(II)tris(bipyridine). We use pump–probe transient absorption

spectroscopy with a high time resolution of <60 fs in the ultraviolet probe range, in which the 5T state absorbs, and of <40 fs in the visible probe range, in which both the hot MLCT

state and the 5T state absorb. Our results show that the 5T state is impulsively populated in less than 50 fs, which is the time we measured for the depopulation of the MCLT manifold. We

propose that non-totally-symmetric modes mediate the process, possibly high-frequency modes of the bipyridine (bpy) ligand. These results show that even though the SCO process in Fe(II)

complexes represents a strongly spin-forbidden (Δ_S_ = 2) two-electron transition, spin flipping occurs at near subvibrational times and is intertwined with the electron and structural

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Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS FERRICYANIDE PHOTO-AQUATION PATHWAY REVEALED BY COMBINED FEMTOSECOND KΒ MAIN LINE AND VALENCE-TO-CORE X-RAY EMISSION

SPECTROSCOPY Article Open access 05 May 2023 SPIN–VIBRONIC COHERENCE DRIVES SINGLET–TRIPLET CONVERSION Article 19 July 2023 BRANCHING MECHANISM OF PHOTOSWITCHING IN AN FE(II) POLYPYRIDYL

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work was supported by the Swiss National Science Foundation via the National Centre of Competence in Research Molecular Ultrafast Science and Technology and by Research Equipment grant

206021_121300. AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, Faculté des Sciences de Base, ISIC, Lausanne,

CH-1015, Switzerland Gerald Auböck & Majed Chergui Authors * Gerald Auböck View author publications You can also search for this author inPubMed Google Scholar * Majed Chergui View

author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS M.C. conceived the experiments, G.A. designed and performed the experiments and analysed the

data, and M.C. and G.A. co-wrote the paper. CORRESPONDING AUTHOR Correspondence to Majed Chergui. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing financial

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Auböck, G., Chergui, M. Sub-50-fs photoinduced spin crossover in [Fe(bpy)3]2+. _Nature Chem_ 7, 629–633 (2015). https://doi.org/10.1038/nchem.2305 Download citation * Received: 27 August

2014 * Accepted: 12 June 2015 * Published: 20 July 2015 * Issue Date: August 2015 * DOI: https://doi.org/10.1038/nchem.2305 SHARE THIS ARTICLE Anyone you share the following link with will

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