Articles producció científica> Química Física i Inorgànica

TD-DFT study of the light-induced spin crossover of Fe(III) complexes

  • Identification data

    Identifier: imarina:5131634
    Authors:
    Saureu, Sergide Graaf, Coen
    Abstract:
    Two light-induced spin-crossover Fe(III) compounds have been studied with time-dependent density functional theory (TD-DFT) to investigate the deactivation mechanism and the role of the ligand-field states as intermediates in this process. The B3LYP* functional has previously shown its ability to accurately describe (light-induced) spin-crossover in Fe(II) complexes. Here, we establish its performance for Fe(III) systems using [Fe(qsal)2]+ (Hqsal = 2-[(8-quinolinylimino)methyl]phenol) and [Fe(pap)2]+ (Hpap = 2-(2-pyridylmethyleneamino)phenol) as test cases comparing the B3LYP* results to experimental information and to multiconfigurational wave function results. In addition to rather accurate high spin (HS) and low spin (LS) state geometries, B3LYP* also predicts ligand-to-metal charge transfer (LMCT) states with large oscillator strength in the energy range where the UV-VIS spectrum shows an intense absorption band, whereas optically allowed π-π* excitations on the ligands were calculated at higher energy. Subsequently, we have generated a two-dimensional potential energy surface of the HS and LS states varying the Fe-N and Fe-O distances. LMCT and metal centered (MC) excited states were followed along the approximate minimal energy path that connects the minima of the HS and LS on this surface. The 2LMCT state has a minimum in the same region as the initial LS state, where we also observe a crossing with the intermediate spin (IS) state. Upon the expansion of the coordination sphere of the Fe(III) ion, the IS state crosses with the HS state and further expansion of the coordination sphere leads to the excited spin state trapping as observed in experiment. The calculation of the intersystem crossing rates reveals that the deactivation from 2LMCT → IS → HS competes with
  • Others:

    Author, as appears in the article.: Saureu, Sergi; de Graaf, Coen;
    Department: Química Física i Inorgànica
    URV's Author/s: De Graaf, Cornelis
    Keywords: Transition-metal complexes Transition Temperature State energetics Spectroscopy Iron(iii) compounds Inorganic chemistry Fe(phen)(2)(ncs)(2) Electronic-structure Electronic structure Dynamics Basis-sets 2nd-order perturbation-theory
    Abstract: Two light-induced spin-crossover Fe(III) compounds have been studied with time-dependent density functional theory (TD-DFT) to investigate the deactivation mechanism and the role of the ligand-field states as intermediates in this process. The B3LYP* functional has previously shown its ability to accurately describe (light-induced) spin-crossover in Fe(II) complexes. Here, we establish its performance for Fe(III) systems using [Fe(qsal)2]+ (Hqsal = 2-[(8-quinolinylimino)methyl]phenol) and [Fe(pap)2]+ (Hpap = 2-(2-pyridylmethyleneamino)phenol) as test cases comparing the B3LYP* results to experimental information and to multiconfigurational wave function results. In addition to rather accurate high spin (HS) and low spin (LS) state geometries, B3LYP* also predicts ligand-to-metal charge transfer (LMCT) states with large oscillator strength in the energy range where the UV-VIS spectrum shows an intense absorption band, whereas optically allowed π-π* excitations on the ligands were calculated at higher energy. Subsequently, we have generated a two-dimensional potential energy surface of the HS and LS states varying the Fe-N and Fe-O distances. LMCT and metal centered (MC) excited states were followed along the approximate minimal energy path that connects the minima of the HS and LS on this surface. The 2LMCT state has a minimum in the same region as the initial LS state, where we also observe a crossing with the intermediate spin (IS) state. Upon the expansion of the coordination sphere of the Fe(III) ion, the IS state crosses with the HS state and further expansion of the coordination sphere leads to the excited spin state trapping as observed in experiment. The calculation of the intersystem crossing rates reveals that the deactivation from 2LMCT → IS → HS competes with the 2LMCT → IS → LS pathway, in line with the low efficiency encountered in experiments.
    Thematic Areas: Química Physics, atomic, molecular & chemical Physics and astronomy (miscellaneous) Physics and astronomy (all) Physical and theoretical chemistry Odontología Medicina ii Medicina i Materiais Matemática / probabilidade e estatística Interdisciplinar Geociências General physics and astronomy General medicine Farmacia Ensino Engenharias iv Engenharias iii Engenharias ii Ciências biológicas ii Ciências biológicas i Ciências ambientais Ciências agrárias i Ciência de alimentos Ciência da computação Chemistry, physical Biotecnología Biodiversidade Astronomia / física
    licence for use: https://creativecommons.org/licenses/by/3.0/es/
    Author's mail: coen.degraaf@urv.cat
    Author identifier: 0000-0001-8114-6658
    Record's date: 2024-09-07
    Papper version: info:eu-repo/semantics/submittedVersion
    Link to the original source: https://pubs.rsc.org/en/content/articlelanding/2016/cp/c5cp06620d
    Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
    Papper original source: Physical Chemistry Chemical Physics. 18 (2): 1233-1244
    APA: Saureu, Sergi; de Graaf, Coen; (2016). TD-DFT study of the light-induced spin crossover of Fe(III) complexes. Physical Chemistry Chemical Physics, 18(2), 1233-1244. DOI: 10.1039/c5cp06620d
    Article's DOI: 10.1039/c5cp06620d
    Entity: Universitat Rovira i Virgili
    Journal publication year: 2016
    Publication Type: Journal Publications
  • Keywords:

    Chemistry, Physical,Physical and Theoretical Chemistry,Physics and Astronomy (Miscellaneous),Physics, Atomic, Molecular & Chemical
    Transition-metal complexes
    Transition
    Temperature
    State energetics
    Spectroscopy
    Iron(iii) compounds
    Inorganic chemistry
    Fe(phen)(2)(ncs)(2)
    Electronic-structure
    Electronic structure
    Dynamics
    Basis-sets
    2nd-order perturbation-theory
    Química
    Physics, atomic, molecular & chemical
    Physics and astronomy (miscellaneous)
    Physics and astronomy (all)
    Physical and theoretical chemistry
    Odontología
    Medicina ii
    Medicina i
    Materiais
    Matemática / probabilidade e estatística
    Interdisciplinar
    Geociências
    General physics and astronomy
    General medicine
    Farmacia
    Ensino
    Engenharias iv
    Engenharias iii
    Engenharias ii
    Ciências biológicas ii
    Ciências biológicas i
    Ciências ambientais
    Ciências agrárias i
    Ciência de alimentos
    Ciência da computação
    Chemistry, physical
    Biotecnología
    Biodiversidade
    Astronomia / física
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