Electronic structure and soft-X-ray-induced photoreduction studies of iron-based magnetic polyoxometalates of type {(M)M-5}(12)Fe-30(III) (M = Mo-VI, W-VI)
Autor(en): | Kuepper, Karsten Derks, Christine Taubitz, Christian Prinz, Manuel Joly, Loic Kappler, Jean-Paul Postnikov, Andrei Yang, Wanli Kuznetsova, Tatyana V. Wiedwald, Ulf Ziemann, Paul Neumann, Manfred |
Stichwörter: | ABSORPTION; Chemistry; Chemistry, Inorganic & Nuclear; DICHROISM; EXCHANGE INTERACTIONS; GIANT CLUSTERS; LIGAND; LINKING; MOLECULAR MAGNETS; PHOTOCHEMISTRY; SPECTROSCOPY | Erscheinungsdatum: | 2013 | Herausgeber: | ROYAL SOC CHEMISTRY | Journal: | DALTON TRANSACTIONS | Volumen: | 42 | Ausgabe: | 22 | Startseite: | 7924 | Seitenende: | 7935 | Zusammenfassung: | Giant Keplerate-type molecules with a {Mo72Fe30} core show a number of very interesting properties, making them particularly promising for various applications. So far, only limited data on the electronic structure of these molecules from X-ray spectra and electronic structure calculations have been available. Here we present a combined electronic and magnetic structure study of three Keplerate-type nanospheres-two with a {Mo72Fe30} core and one with a {W72Fe30} core by means of X-ray absorption spectroscopy, X-ray magnetic circular dichroism (XMCD), SQUID magnetometry, and complementary theoretical approaches. Furthermore, we present detailed studies of the Fe3+-to-Fe2+ photoreduction process, which is induced under soft X-ray radiation in these molecules. We observe that the photoreduction rate greatly depends on the ligand structure surrounding the Fe ions, with negatively charged ligands leading to a dramatically reduced photoreduction rate. This opens the possibility of tailoring such polyoxometalates by X-ray spectroscopic studies and also for potential applications in the field of X-ray induced photochemistry. |
ISSN: | 14779226 | DOI: | 10.1039/c3dt32759k |
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geprüft am 29.05.2024