Details
| Original language | English |
|---|---|
| Pages (from-to) | 3141-3154 |
| Number of pages | 14 |
| Journal | European Journal of Inorganic Chemistry |
| Issue number | 21 |
| Publication status | Published - Jul 2009 |
Abstract
A nonsymmetrical triamine, l,6-diamino-4-azahexane, was Schiff-condensed with (X-substituted) o-salicylaldehyde to yield pentadentate ligands X-L 5: salpet and MeBu-salpet, These ligands form, mononuclear, dinuclear, and trinuclear FeIII complexes, whose structures were determined by single-crystal X-ray analysis. Of the mononuclear complexes, [FeIII(salpet)Cl] and [FeIII(MeBu-salpet)Cl] are high spin (S = 5/2), whereas [FeIII(salpet)CN]-MeOH is low spin (S = 1/2). The dinuclear and trinuclear complexes show a kind of thermally induced spin crossover. The dinuclear complex [L5FeIII(CN)Fe IIIL5](ClO4)-2H2O (L5 = salpet) is a mixed-spin assembly: the C-coordinated FeIII center is low spin (L) and the N-coordinated FeIII center is high spin (H) at: low temperature; an antiferromagnetic interaction occurs between them. This LH reference state is mixed with the LL one. Upon heating, the system shows an increasing content of the HH state. Also, the dinuclear complex [L 5FeIII(CN)FeIIIL5](BPh 4)2MeCN (L5 = MeBu-salpet) exhibits a spin transition between LH and HH spin pairs. The mixed-valence trinuclear complex [L 5FeIII{FeII(CN)5(NO)}Fe IIIL5]-0.5MeOH-3.75H2O (L5 = salpet) shows spin crossover with a residual high-spin fraction at liquid He temperature owing to the LL + LH ground state. The metallacyanido-bridged complex [L5FeIII{Ni(CN)4}FeIIIL 5]-2MeOH (L5 = MeBu-salpet) contains a high-spin pair, HH, over the whole temperature interval with a ferromagnetic exchange interaction. A. theoretical model was outlined that allows simultaneous fitting of all available experimental data (magnetic susceptibility, magnetization, high-spin mole fraction obtained, from, the Mössbauer spectra) on a common set of parameters.
Keywords
- Exchange interactions, Iron, Schiff bases, Spin crossover, Structure elucidation
ASJC Scopus subject areas
- Chemistry(all)
- Inorganic Chemistry
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In: European Journal of Inorganic Chemistry, No. 21, 07.2009, p. 3141-3154.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Unconventional spin crossover in dinuclear and trinuclear iron(III) complexes with cyanido and metallacyanido bridges
AU - Šalitroš, Ivan
AU - Boča, Roman
AU - Dlháň, L'ubor
AU - Gembický, Milan
AU - Kožíšek, Jozef
AU - Linares, Jorge
AU - Moncol, Ján
AU - Nemec, Ivan
AU - Perašínová, Lucia
AU - Renz, Franz
AU - Svoboda, Ingrid
AU - Fuess, Hartmut
PY - 2009/7
Y1 - 2009/7
N2 - A nonsymmetrical triamine, l,6-diamino-4-azahexane, was Schiff-condensed with (X-substituted) o-salicylaldehyde to yield pentadentate ligands X-L 5: salpet and MeBu-salpet, These ligands form, mononuclear, dinuclear, and trinuclear FeIII complexes, whose structures were determined by single-crystal X-ray analysis. Of the mononuclear complexes, [FeIII(salpet)Cl] and [FeIII(MeBu-salpet)Cl] are high spin (S = 5/2), whereas [FeIII(salpet)CN]-MeOH is low spin (S = 1/2). The dinuclear and trinuclear complexes show a kind of thermally induced spin crossover. The dinuclear complex [L5FeIII(CN)Fe IIIL5](ClO4)-2H2O (L5 = salpet) is a mixed-spin assembly: the C-coordinated FeIII center is low spin (L) and the N-coordinated FeIII center is high spin (H) at: low temperature; an antiferromagnetic interaction occurs between them. This LH reference state is mixed with the LL one. Upon heating, the system shows an increasing content of the HH state. Also, the dinuclear complex [L 5FeIII(CN)FeIIIL5](BPh 4)2MeCN (L5 = MeBu-salpet) exhibits a spin transition between LH and HH spin pairs. The mixed-valence trinuclear complex [L 5FeIII{FeII(CN)5(NO)}Fe IIIL5]-0.5MeOH-3.75H2O (L5 = salpet) shows spin crossover with a residual high-spin fraction at liquid He temperature owing to the LL + LH ground state. The metallacyanido-bridged complex [L5FeIII{Ni(CN)4}FeIIIL 5]-2MeOH (L5 = MeBu-salpet) contains a high-spin pair, HH, over the whole temperature interval with a ferromagnetic exchange interaction. A. theoretical model was outlined that allows simultaneous fitting of all available experimental data (magnetic susceptibility, magnetization, high-spin mole fraction obtained, from, the Mössbauer spectra) on a common set of parameters.
AB - A nonsymmetrical triamine, l,6-diamino-4-azahexane, was Schiff-condensed with (X-substituted) o-salicylaldehyde to yield pentadentate ligands X-L 5: salpet and MeBu-salpet, These ligands form, mononuclear, dinuclear, and trinuclear FeIII complexes, whose structures were determined by single-crystal X-ray analysis. Of the mononuclear complexes, [FeIII(salpet)Cl] and [FeIII(MeBu-salpet)Cl] are high spin (S = 5/2), whereas [FeIII(salpet)CN]-MeOH is low spin (S = 1/2). The dinuclear and trinuclear complexes show a kind of thermally induced spin crossover. The dinuclear complex [L5FeIII(CN)Fe IIIL5](ClO4)-2H2O (L5 = salpet) is a mixed-spin assembly: the C-coordinated FeIII center is low spin (L) and the N-coordinated FeIII center is high spin (H) at: low temperature; an antiferromagnetic interaction occurs between them. This LH reference state is mixed with the LL one. Upon heating, the system shows an increasing content of the HH state. Also, the dinuclear complex [L 5FeIII(CN)FeIIIL5](BPh 4)2MeCN (L5 = MeBu-salpet) exhibits a spin transition between LH and HH spin pairs. The mixed-valence trinuclear complex [L 5FeIII{FeII(CN)5(NO)}Fe IIIL5]-0.5MeOH-3.75H2O (L5 = salpet) shows spin crossover with a residual high-spin fraction at liquid He temperature owing to the LL + LH ground state. The metallacyanido-bridged complex [L5FeIII{Ni(CN)4}FeIIIL 5]-2MeOH (L5 = MeBu-salpet) contains a high-spin pair, HH, over the whole temperature interval with a ferromagnetic exchange interaction. A. theoretical model was outlined that allows simultaneous fitting of all available experimental data (magnetic susceptibility, magnetization, high-spin mole fraction obtained, from, the Mössbauer spectra) on a common set of parameters.
KW - Exchange interactions
KW - Iron
KW - Schiff bases
KW - Spin crossover
KW - Structure elucidation
UR - http://www.scopus.com/inward/record.url?scp=67650815747&partnerID=8YFLogxK
U2 - 10.1002/ejic.200900169
DO - 10.1002/ejic.200900169
M3 - Article
AN - SCOPUS:67650815747
SP - 3141
EP - 3154
JO - European Journal of Inorganic Chemistry
JF - European Journal of Inorganic Chemistry
SN - 1434-1948
IS - 21
ER -