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Resonant X-ray photo-oxidation of light-harvesting iron (II/III) N-heterocyclic carbene complexes
Two photoactive iron N-heterocyclic carbene complexes [Formula: see text] and [Formula: see text] , where btz is 3,3’-dimethyl-1,1’-bis(p-tolyl)-4,4’-bis(1,2,3-triazol-5-ylidene) and bpy is 2,2’-bipyridine, have been investigated by Resonant Photoelectron Spectroscopy (RPES). Tuning the incident X-r...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8590020/ https://www.ncbi.nlm.nih.gov/pubmed/34772983 http://dx.doi.org/10.1038/s41598-021-01509-7 |
Sumario: | Two photoactive iron N-heterocyclic carbene complexes [Formula: see text] and [Formula: see text] , where btz is 3,3’-dimethyl-1,1’-bis(p-tolyl)-4,4’-bis(1,2,3-triazol-5-ylidene) and bpy is 2,2’-bipyridine, have been investigated by Resonant Photoelectron Spectroscopy (RPES). Tuning the incident X-ray photon energy to match core-valence excitations provides a site specific probe of the electronic structure properties and ligand-field interactions, as well as information about the resonantly photo-oxidised final states. Comparing measurements of the Fe centre and the surrounding ligands demonstrate strong mixing of the Fe [Formula: see text] levels with occupied ligand [Formula: see text] orbitals but weak mixing with the corresponding unoccupied ligand orbitals. This highlights the importance of [Formula: see text] -accepting and -donating considerations in ligand design strategies for photofunctional iron carbene complexes. Spin-propensity is also observed as a final-state effect in the RPES measurements of the open-shell [Formula: see text] complex. Vibronic coupling is evident in both complexes, where the energy dispersion hints at a vibrationally hot final state. The results demonstrate the significant impact of the iron oxidation state on the frontier electronic structure and highlights the differences between the emerging class of [Formula: see text] photosensitizers from those of more traditional [Formula: see text] complexes. |
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