Exceptional excited-state lifetime of an iron(II)- N -heterocyclic carbene complex explained

Lisa A. Fredin, Mátyás Pápai, Emese Rozsályi, G. Vankó, Kenneth Wärnmark, Villy Sundström, Petter Persson

Research output: Contribution to journalArticle

70 Citations (Scopus)

Abstract

Earth-abundant transition-metal complexes are desirable for sensitizers in dye-sensitized solar cells or photocatalysts. Iron is an obvious choice, but the energy level structure of its typical polypyridyl complexes, featuring low-lying metal-centered states, has made such complexes useless as energy converters. Recently, we synthesized a novel iron-N-heterocyclic carbene complex exhibiting a remarkable 100-fold increase of the lifetime compared to previously known iron(II) complexes. Here, we rationalize the measured excited-state dynamics with DFT and TD-DFT calculations. The calculations show that the exceptionally long excited-state lifetime (∼9 ps) is achieved for this Fe complex through a significant destabilization of both triplet and quintet metal-centered scavenger states compared to other FeII complexes. In addition, a shallow 3MLCT potential energy surface with a low-energy transition path from the 3MLCT to 3MC and facile crossing from the 3MC state to the ground state are identified as key features for the excited-state deactivation.

Original languageEnglish
Pages (from-to)2066-2071
Number of pages6
JournalJournal of Physical Chemistry Letters
Volume5
Issue number12
DOIs
Publication statusPublished - Jun 19 2014

Fingerprint

carbenes
Excited states
Iron
iron
Discrete Fourier transforms
life (durability)
Metals
direct power generators
excitation
Potential energy surfaces
Coordination Complexes
destabilization
Photocatalysts
Metal complexes
deactivation
metals
Electron energy levels
Ground state
Transition metals
solar cells

Keywords

  • density functional theory
  • excited-state dynamics
  • N -heterocyclic carbene
  • potential energy surfaces

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Fredin, L. A., Pápai, M., Rozsályi, E., Vankó, G., Wärnmark, K., Sundström, V., & Persson, P. (2014). Exceptional excited-state lifetime of an iron(II)- N -heterocyclic carbene complex explained. Journal of Physical Chemistry Letters, 5(12), 2066-2071. https://doi.org/10.1021/jz500829w

Exceptional excited-state lifetime of an iron(II)- N -heterocyclic carbene complex explained. / Fredin, Lisa A.; Pápai, Mátyás; Rozsályi, Emese; Vankó, G.; Wärnmark, Kenneth; Sundström, Villy; Persson, Petter.

In: Journal of Physical Chemistry Letters, Vol. 5, No. 12, 19.06.2014, p. 2066-2071.

Research output: Contribution to journalArticle

Fredin, LA, Pápai, M, Rozsályi, E, Vankó, G, Wärnmark, K, Sundström, V & Persson, P 2014, 'Exceptional excited-state lifetime of an iron(II)- N -heterocyclic carbene complex explained', Journal of Physical Chemistry Letters, vol. 5, no. 12, pp. 2066-2071. https://doi.org/10.1021/jz500829w
Fredin, Lisa A. ; Pápai, Mátyás ; Rozsályi, Emese ; Vankó, G. ; Wärnmark, Kenneth ; Sundström, Villy ; Persson, Petter. / Exceptional excited-state lifetime of an iron(II)- N -heterocyclic carbene complex explained. In: Journal of Physical Chemistry Letters. 2014 ; Vol. 5, No. 12. pp. 2066-2071.
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