A mononuclear Fe(III) single molecule magnet with a 3/2↔5/2 spin crossover

Beitrag in einer Fachzeitschrift
(Originalarbeit)


Details zur Publikation

Autorinnen und Autoren: Mossin S, Tran BL, Adhikari D, Pink M, Heinemann F, Sutter J, Szilagyi RK, Meyer K, Mindiola DJ
Zeitschrift: Journal of the American Chemical Society
Verlag: American Chemical Society
Jahr der Veröffentlichung: 2012
Band: 134
Heftnummer: 33
Seitenbereich: 13651-13661
ISSN: 0002-7863


Abstract


The air stable complex [(PNP)FeCl2] (1) (PNP = N[2-P(CHMe2)(2)-4-methylphenyl](2)(-)), prepared from one-electron oxidation of [(PNP)FeCl] with ClCPh3, displays an unexpected S = 3/2 to S = 5/2 transition above 80 K as inferred by the dc SQUID magnetic susceptibility measurement The ac SQUID magnetization data, at zero field and between frequencies 10 and 1042 Hz, dearly reveal complex 1 to have frequency dependence on the out-of-phase signal and thus being a single molecular magnet with a thermally activated barrier of U-eff = 32-36 cm(-1) (47-52 K). Variable-temperature Mossbauer data also corroborate a significant temperature dependence in delta and Delta E-Q values for 1, which is in agreement with the system undergoing a change in spin state. Likewise, variable temperature X-band EPR spectra of 1 reveals the S = 3/2 to be likely the ground state with the S = 5/2 being close in energy. Multiedge XAS absorption spectra suggest the electronic structure of 1 to be highly covalent with an effective iron oxidation state that is more reduced than the typical ferric complexes due to the significant interaction of the phosphine groups in PNP and Cl ligands with iron. A variable temperature single crystal X-ray diffraction study of 1 collected between 30 and 300 K also reveals elongation of the Fe-P bond lengths and increment in the Cl-Fe-Cl angle as the S = 5/2 state is populated Theoretical studies show overall similar orbital pictures except for the d(z(2)) orbital, which has the most sensitivity to change in the geometry and bonding, where the quartet (B-4) and the sextet ((6)A) states are close in energy.



FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Heinemann, Frank Dr.
Lehrstuhl für Anorganische und Allgemeine Chemie
Meyer, Karsten Prof. Dr.
Lehrstuhl für Anorganische und Allgemeine Chemie
Sutter, Jörg Dr.
Lehrstuhl für Anorganische und Allgemeine Chemie


Einrichtungen weiterer Autorinnen und Autoren

Indiana University
Montana State University
Technical University of Denmark / Danmarks Tekniske Universitet (DTU)


Zitierweisen

APA:
Mossin, S., Tran, B.L., Adhikari, D., Pink, M., Heinemann, F., Sutter, J.,... Mindiola, D.J. (2012). A mononuclear Fe(III) single molecule magnet with a 3/2↔5/2 spin crossover. Journal of the American Chemical Society, 134(33), 13651-13661. https://dx.doi.org/10.1021/ja302660k

MLA:
Mossin, Susanne, et al. "A mononuclear Fe(III) single molecule magnet with a 3/2↔5/2 spin crossover." Journal of the American Chemical Society 134.33 (2012): 13651-13661.

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Zuletzt aktualisiert 2019-09-04 um 14:51