Photooxidation and photoaquation of iron hexacyanide in aqueous solution: A picosecond X-ray absorption study
We present a picosecond Fe K-edge absorption study of photoexcited ferrous and ferric hexacyanide in water under 355 and 266 nm excitation. Following 355 nm excitation, the transient spectra for the ferrous and ferric complexes exhibit a red shift of the edge reflecting...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC and ACA
2014-03-01
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| Series: | Structural Dynamics |
| Online Access: | http://dx.doi.org/10.1063/1.4871751 |
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| author | M. Reinhard T. J. Penfold F. A. Lima J. Rittmann M. H. Rittmann-Frank R. Abela I. Tavernelli U. Rothlisberger C. J. Milne M. Chergui |
| author_facet | M. Reinhard T. J. Penfold F. A. Lima J. Rittmann M. H. Rittmann-Frank R. Abela I. Tavernelli U. Rothlisberger C. J. Milne M. Chergui |
| author_sort | M. Reinhard |
| collection | DOAJ |
| description | We present a picosecond Fe K-edge absorption study of photoexcited ferrous and ferric
hexacyanide in water under 355 and 266 nm excitation. Following 355 nm excitation, the
transient spectra for the ferrous and ferric complexes exhibit a red shift of the edge
reflecting an increased electron density at the Fe atom. For the former, an enhanced
pre-edge transition is also observed. These observations are attributed to the aquated
[Fe(CN)5OH2]3− species, based on quantum chemical
calculations which also provide structural parameters. Upon 266 nm excitation of the
ferric complex, a transient reminiscent of the aquated species is observed (appearance of
a pre-edge feature and red
shift of the edge) but it is different from that obtained under 355 nm
excitation. This points to a new reaction channel occurring through an intermediate
state lying between these two excitation energies. Finally, 266 nm excitation of the
ferrous species is dominated by the photooxidation channel with formation of the ferric
complex as main photoproduct. However, we observe an additional minor photoproduct, which
is identical to the 266 nm generated photoproduct of the ferric species, suggesting that
under our experimental conditions, the pump pulse photooxidises the ferrous complex and
re-excites the primary ferric photoproduct. |
| first_indexed | 2024-12-23T19:48:39Z |
| format | Article |
| id | doaj.art-d1a1466d43ac48589581975808dba72d |
| institution | Directory Open Access Journal |
| issn | 2329-7778 |
| language | English |
| last_indexed | 2024-12-23T19:48:39Z |
| publishDate | 2014-03-01 |
| publisher | AIP Publishing LLC and ACA |
| record_format | Article |
| series | Structural Dynamics |
| spelling | doaj.art-d1a1466d43ac48589581975808dba72d2022-12-21T17:33:26ZengAIP Publishing LLC and ACAStructural Dynamics2329-77782014-03-0112024901024901-1210.1063/1.4871751006402SDYPhotooxidation and photoaquation of iron hexacyanide in aqueous solution: A picosecond X-ray absorption studyM. Reinhard0T. J. Penfold1F. A. Lima2J. Rittmann3M. H. Rittmann-Frank4R. Abela5I. Tavernelli6U. Rothlisberger7C. J. Milne8M. Chergui9Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, FSB, CH-1015 Lausanne, SwitzerlandEcole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, FSB, CH-1015 Lausanne, SwitzerlandEcole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, FSB, CH-1015 Lausanne, SwitzerlandEcole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, FSB, CH-1015 Lausanne, SwitzerlandEcole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, FSB, CH-1015 Lausanne, SwitzerlandSwissFEL, Paul Scherrer Inst, CH-5232 Villigen, SwitzerlandEcole Polytechnique Fédérale de Lausanne, Laboratoire de Chimie et Biochimie Computationnelles, ISIC, FSB, CH-1015 Lausanne, SwitzerlandEcole Polytechnique Fédérale de Lausanne, Laboratoire de Chimie et Biochimie Computationnelles, ISIC, FSB, CH-1015 Lausanne, SwitzerlandEcole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, FSB, CH-1015 Lausanne, SwitzerlandEcole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, FSB, CH-1015 Lausanne, SwitzerlandWe present a picosecond Fe K-edge absorption study of photoexcited ferrous and ferric hexacyanide in water under 355 and 266 nm excitation. Following 355 nm excitation, the transient spectra for the ferrous and ferric complexes exhibit a red shift of the edge reflecting an increased electron density at the Fe atom. For the former, an enhanced pre-edge transition is also observed. These observations are attributed to the aquated [Fe(CN)5OH2]3− species, based on quantum chemical calculations which also provide structural parameters. Upon 266 nm excitation of the ferric complex, a transient reminiscent of the aquated species is observed (appearance of a pre-edge feature and red shift of the edge) but it is different from that obtained under 355 nm excitation. This points to a new reaction channel occurring through an intermediate state lying between these two excitation energies. Finally, 266 nm excitation of the ferrous species is dominated by the photooxidation channel with formation of the ferric complex as main photoproduct. However, we observe an additional minor photoproduct, which is identical to the 266 nm generated photoproduct of the ferric species, suggesting that under our experimental conditions, the pump pulse photooxidises the ferrous complex and re-excites the primary ferric photoproduct.http://dx.doi.org/10.1063/1.4871751 |
| spellingShingle | M. Reinhard T. J. Penfold F. A. Lima J. Rittmann M. H. Rittmann-Frank R. Abela I. Tavernelli U. Rothlisberger C. J. Milne M. Chergui Photooxidation and photoaquation of iron hexacyanide in aqueous solution: A picosecond X-ray absorption study Structural Dynamics |
| title | Photooxidation and photoaquation of iron hexacyanide in aqueous solution: A
picosecond X-ray absorption study |
| title_full | Photooxidation and photoaquation of iron hexacyanide in aqueous solution: A
picosecond X-ray absorption study |
| title_fullStr | Photooxidation and photoaquation of iron hexacyanide in aqueous solution: A
picosecond X-ray absorption study |
| title_full_unstemmed | Photooxidation and photoaquation of iron hexacyanide in aqueous solution: A
picosecond X-ray absorption study |
| title_short | Photooxidation and photoaquation of iron hexacyanide in aqueous solution: A
picosecond X-ray absorption study |
| title_sort | photooxidation and photoaquation of iron hexacyanide in aqueous solution a picosecond x ray absorption study |
| url | http://dx.doi.org/10.1063/1.4871751 |
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