This website uses cookies

The University of Liège wishes to use cookies or trackers to store and access your personal data, to perform audience measurement. Some cookies are necessary for the website to function. Cookie policy.

Article (Scientific journals)
Slow Magnetic Relaxation and Electron Delocalization in an S = 9/2 Iron(II/III) Complex Featuring Two Crystallographically Inequivalent Iron Sites
Hazra, Susanta; Sasmal, Sujit; Fleck, Michel et al.
2011In Journal of Chemical Physics, 134, p. 174507
Peer Reviewed verified by ORBi
 

Files


Full Text
JChemPhys134(2011)174507.pdf
Publisher postprint (955.33 kB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
single molecule magnet; class III mixed valence compound; Mössbauer spectroscopy
Abstract :
[en] The magnetic, electronic and Mössbauer spectral properties of [Fe2L(μ-OAc)2]ClO4, 1, where L is the dianion of the tetraimino-diphenolate macrocyclic ligand, H2L, indicate that 1 is a class III mixed valence iron(II/III) complex with an electron that is fully delocalized between two crystallographically inequivalent iron sites to yield a [Fe2]V cationic configuration with a St = 9/2 ground state. Fits of the dc magnetic susceptibility between 2 and 300 K and of the isofield variable-temperature magnetization of 1 yield an isotropic magnetic exchange parameter, J, of –32(2) cm–1 for an electron transfer parameter, B, of 950 cm–1, a zero-field uniaxial D9/2 parameter of –0.9(1) cm–1, and g = 1.95(5). In agreement with the presence of uniaxial magnetic anisotropy, ac susceptibility measurements reveal that 1 is a single-molecule magnet at low temperature with a single molecule magnetic effective relaxation barrier, Ueff, of 9.8 cm–1. At 5.25 K the Mössbauer spectra of 1 exhibit two spectral components, assigned to the two crystallographically inequivalent iron sites with a static effective hyperfine field; as the temperature increases from 7 to 310 K the spectra exhibit increasingly rapid relaxation of the hyperfine field on the iron-57 Larmor precession time of 5 × 10–8 s. A fit of the temperature dependence of the average effective hyperfine field yields |D9/2| = 0.9 cm–1. An Arrhenius plot of the logarithm of the relaxation frequency between 5 and 85 K yields a relaxation barrier of 17 cm–1.
Disciplines :
Chemistry
Author, co-author :
Hazra, Susanta;  University of Calcutta > Chemistry
Sasmal, Sujit;  University of Calcutta > Chemistry
Fleck, Michel;  University of Vienna > Institute for Mineralogy and Crystallography
Grandjean, Fernande ;  Université de Liège - ULiège > Département de physique > Département de physique
Sougrati, Moulay T.;  University of Liege > Physics
Ghosh, Meenakshi;  Max Planck Institut Bioanorganische CHemie
Harris, T David;  Berkeley University of California - UC Berkeley > Chemistry
Bonville, Pierre;  CEA Saclay > Physique de la Matiere Condensée
Long, Gary J;  Missouri University of Science and Technology > Chemistry
Mohanta, Sasankasekhar;  University of Calcutta > Chemistry
Language :
English
Title :
Slow Magnetic Relaxation and Electron Delocalization in an S = 9/2 Iron(II/III) Complex Featuring Two Crystallographically Inequivalent Iron Sites
Alternative titles :
[en] Relaxation magnétique lente et délocalisation électronique dans un complexe de fer(II/III) avec S=9/2 et deux sites cristallographiques inéquivalents
Publication date :
06 May 2011
Journal title :
Journal of Chemical Physics
ISSN :
0021-9606
eISSN :
1089-7690
Publisher :
American Institute of Physics, New York, United States - New York
Volume :
134
Pages :
174507
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 06 August 2011

Statistics


Number of views
74 (5 by ULiège)
Number of downloads
1 (1 by ULiège)

Scopus citations®
 
29
Scopus citations®
without self-citations
10
OpenCitations
 
28
OpenAlex citations
 
27

Bibliography


Similar publications



Sorry the service is unavailable at the moment. Please try again later.
Contact ORBi