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Synthesis, magnetism, and 57Fe Mössbauer spectroscopic study of a family of [Ln3Fe7] coordination clusters (Ln = Gd, Tb, and Er)
- Source :
- Inorganic Chemistry, Inorganic Chemistry, American Chemical Society, 2013, 52 (20), pp.11767-11777. ⟨10.1021/ic401011d⟩
- Publication Year :
- 2013
-
Abstract
- The reaction of N-methydiethanolamine (mdeaH2), benzoic acid, FeCl3, and Ln(NO3)3·6H2O or LnCl3·xH2O yields a series of decanuclear coordination clusters, [Ln3Fe7(μ4-O)2(μ3-OH)2(mdea)7(μ-benzoate)4(N3)6]·4MeCN·H2O, where Ln = Gd(III) (1) or Tb(III) (2), and [Er3Fe7(μ4-O)2(μ3-OH)2(mdea)7(μ-benzoate)4(N3)5(MeOH)]Cl·7.5H2O·11.5MeOH (3). The isostructural compounds 1-3 all crystallize isotypically in the triclinic space group P1̅ with Z = 2, as does the previously reported dysprosium analogue 4. Six of the Fe(III) ions are pseudooctahedrally coordinated, whereas the seventh has a trigonal-bipyramidal coordination geometry. Temperature-dependent direct-current magnetic susceptibility studies indicate that intracluster antiferromagnetic interactions are dominant in 1-3. The frequency-dependent out-of-phase (χ″) alternating-current susceptibility reveals that 2 undergoes a slow relaxation of its magnetization, presumably resulting from anisotropy of the Tb(III) ions. Between 30 and 295 K, the (57)Fe Mössbauer spectra reveal paramagnetic behavior with six partially resolved quadrupole doublets, one for the trigonal-bipyramidal Fe(III) site and five for the six pseudooctahedral Fe(III) sites. The Mössbauer spectra of 2 and 3 obtained between 3 and 30 K are consistent with the presence of Fe(III) intracluster antiferromagnetic coupling with slow magnetic relaxation relative to the Larmor precession time. Further, the observed changes in the effective magnetic field values in the spectra measured at 3 K with increasing applied field are consistent with the effect of the local spin polarization along the applied magnetic field direction, a behavior reminiscent of antiparallel spin-coupled iron molecular paramagnetic systems.
- Subjects :
- 010405 organic chemistry
Chemistry
chemistry.chemical_element
[CHIM.MATE]Chemical Sciences/Material chemistry
Triclinic crystal system
010402 general chemistry
01 natural sciences
Magnetic susceptibility
0104 chemical sciences
Inorganic Chemistry
Magnetization
Crystallography
Nuclear magnetic resonance
Mössbauer spectroscopy
Dysprosium
Antiferromagnetism
Physical and Theoretical Chemistry
Isostructural
ComputingMilieux_MISCELLANEOUS
Coordination geometry
Subjects
Details
- ISSN :
- 1520510X and 00201669
- Volume :
- 52
- Issue :
- 20
- Database :
- OpenAIRE
- Journal :
- Inorganic chemistry
- Accession number :
- edsair.doi.dedup.....4477e0d5b54d16d4788da41fa11dbcb4