Multifaceted Deactivation Dynamics of Fe(II) N-Heterocyclic Carbene Photosensitizers

Summary, in English

Excited state dynamics of three iron(II) carbene complexes that serve as prototype Earth-abundant photosensitizers were investigated by ultrafast optical spectroscopy. Significant differences in the dynamics between the investigated complexes down to femtosecond time scales are used to characterize fundamental differences in the depopulation of triplet metal-to-ligand charge-transfer (³MLCT) excited states in the presence of energetically accessible triplet metal-centered (³MC) states. Novel insights into the full deactivation cascades of the investigated complexes include evidence of the need to revise the deactivation model for a prominent iron carbene prototype complex, a refined understanding of complex ³MC dynamics, and a quantitative discrimination between activated and barrierless deactivation steps along the ³MLCT → ³MC → ¹GS path. Overall, the study provides an improved understanding of photophysical limitations and opportunities for the use of iron(II)-based photosensitizers in photochemical applications.

• Author: Linnea Lindh; Torbjörn Pascher; Samuel Persson; Yogesh Goriya; Kenneth Wärnmark; Jens Uhlig; Pavel Chábera; Petter Persson; Arkady Yartsev
• Department/s: Chemical Physics; NanoLund: Centre for Nanoscience; eSSENCE: The e-Science Collaboration; LTH Profile Area: Nanoscience and Semiconductor Technology; LU Profile Area: Light and Materials; Centre for Analysis and Synthesis; LTH Profile Area: Photon Science and Technology; Computational Chemistry
• Publishing year: 2023-12
• Language: English
• Pages: 10210-10222
• Publication/Series: Journal of Physical Chemistry A
• Volume: 127
• Issue: 48
• Links: http://dx.doi.org/10.1021/acs.jpca.3c06983
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Atom and Molecular Physics and Optics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1089-5639