Articles producció científica> Química Física i Inorgànica

Ultrafast deactivation mechanism of the excited singlet in the light-induced spin crossover of [Fe(2,2-bipyridine)3]2+

  • Identification data

    Identifier: PC:539
    Handle: https://hdl.handle.net/20.500.11797/PC539
    Authors:
    Sousa, C.De Graaf, C.Rudavskyi, A.Broer, R.Tatchen, J.Etinski, M.Marian, C.M.
    Abstract:
    10.1002/chem.201302992

  • Others:

    Author, as appears in the article.: Sousa, C. De Graaf, C. Rudavskyi, A. Broer, R. Tatchen, J. Etinski, M. Marian, C.M.
    Papper version: info:eu-repo/semantics/submittedVersion
    Department: Química Física i Inorgànica
    Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
    Abstract: The mechanism of the light-induced spin crossover of the [Fe(bpy)3] 2+ complex (bpy = 2,2’-bipyridine) is studied by combining accurate electronic structure calculations and time-dependent approaches to calculate intersystem crossing rates. We investigate how the initially excited metal-to-ligand charge transfer (MLCT) singlet state deactivates to the final metastable high-spin state. Although ultrafast x-ray free electron spectroscopy has established that the total time scale of this process is on the order of a few tenths of a picosecond, the details of the mechanisms still remain unclear. We determine all the intermediate electronic states along the pathway from low-spin to high-spin and give estimates for the deactivation times of the different stages. The calculations result in a total deactivation time on the same order of magnitude as the experimentally determined rate and indicate that the complex can reach the final high-spin state via different deactivation channels. The optically populated excited singlet state rapidly decays to a triplet state with an Fe-d 6 (t 5 2ge 1 g) configuration either directly or via a triplet MLCT state. This triplet ligand field state could in principle decay directly to the final quintet state, but a much faster channel is provided by internal conversion to a lower-lying triplet state and subsequent intersystem crossing to the high-spin state. The deactivation rate to the low-spin ground state is much smaller, in line with the large quantum yield reported for the process.
    Entity: Universitat Rovira i Virgili.
    Journal publication year: 2013
    licence for use: https://creativecommons.org/licenses/by/3.0/es/
    ISSN: 1521-3765
    First page: 17541
    Last page: 17551
    Journal volume: 19