Details
| Original language | English |
|---|---|
| Pages (from-to) | 95-104 |
| Number of pages | 10 |
| Journal | Vibrational spectroscopy |
| Volume | 14 |
| Issue number | 1 |
| Publication status | Published - Mar 1997 |
Abstract
4-X-2,6-bis-(benzimidazol-2′-yl)-pyridine (X-bzimpy; X = H, Cl, OH) molecules coordinate with iron(II) as tridentate ligands forming complexes of distorted octahedral symmetry. The imino-hydrogen of the coordinated ligand of the complexes, [Fe(X-bzimpy)2]2+ is deprotonated in triethylamine solution. The deprotonated complexes, [Fe(X-bzimpyH-1)2] as well as [Fe(X-bzimpy)2]2+ were investigated by UV-VIS and FT-IR, Moessbauer spectroscopy. Quantum-mechanical calculations of the different species were performed and the derived parameters found to be in good agreement with the measured ones. The solid deprotonated complexes, showing in general thermal induced spincrossover, are predominantly at their low-spin (LS) state at room temperature in solid state. In contrast, a pronounced spin-crossover can be observed in methanolic solution. Thermodynamic parameters for [Fe(II-bzimpy)2]2+ and [Fe(H-bzimpyH-1)2] are derived in methanolic solution as ΔH and ΔS as 22.7 ± 0.6, 25.6 ± 1.2 kJ/mol and 85.1 ± 2.1, 92.8 ± 4.3 J/K/mol, respectively. In solid state for [Fe(H-bzimpy)2]2+, ΔH and ΔS were 13.3 ± 2.4 kJ/mol and 42.5 ± 8.6 J/K/mol, respectively.
Keywords
- 4-X-2,6-bis-(benzimidazol-2′-yl)-pyridine, Deprotonation, Spin-transition, Thermodynamic parameters, [Fe(X-bzimpyH)]
ASJC Scopus subject areas
- Chemistry(all)
- Spectroscopy
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In: Vibrational spectroscopy, Vol. 14, No. 1, 03.1997, p. 95-104.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Experimental spin-crossover investigations on charged and neutral iron(II) complexes with 4-substituted-2,6-bis-(benzimidazol-2′-yl) pyridine
AU - Enamullah, M.
AU - Renz, F.
AU - El-Ayaan, U.
AU - Wiesinger, G.
AU - Linert, W.
N1 - Funding Information: Thanks are due to the Fonds zur Förderung der wissenschaftlichen Forschung (Projects CHE-10818 and CHE-11218) for financial support.
PY - 1997/3
Y1 - 1997/3
N2 - 4-X-2,6-bis-(benzimidazol-2′-yl)-pyridine (X-bzimpy; X = H, Cl, OH) molecules coordinate with iron(II) as tridentate ligands forming complexes of distorted octahedral symmetry. The imino-hydrogen of the coordinated ligand of the complexes, [Fe(X-bzimpy)2]2+ is deprotonated in triethylamine solution. The deprotonated complexes, [Fe(X-bzimpyH-1)2] as well as [Fe(X-bzimpy)2]2+ were investigated by UV-VIS and FT-IR, Moessbauer spectroscopy. Quantum-mechanical calculations of the different species were performed and the derived parameters found to be in good agreement with the measured ones. The solid deprotonated complexes, showing in general thermal induced spincrossover, are predominantly at their low-spin (LS) state at room temperature in solid state. In contrast, a pronounced spin-crossover can be observed in methanolic solution. Thermodynamic parameters for [Fe(II-bzimpy)2]2+ and [Fe(H-bzimpyH-1)2] are derived in methanolic solution as ΔH and ΔS as 22.7 ± 0.6, 25.6 ± 1.2 kJ/mol and 85.1 ± 2.1, 92.8 ± 4.3 J/K/mol, respectively. In solid state for [Fe(H-bzimpy)2]2+, ΔH and ΔS were 13.3 ± 2.4 kJ/mol and 42.5 ± 8.6 J/K/mol, respectively.
AB - 4-X-2,6-bis-(benzimidazol-2′-yl)-pyridine (X-bzimpy; X = H, Cl, OH) molecules coordinate with iron(II) as tridentate ligands forming complexes of distorted octahedral symmetry. The imino-hydrogen of the coordinated ligand of the complexes, [Fe(X-bzimpy)2]2+ is deprotonated in triethylamine solution. The deprotonated complexes, [Fe(X-bzimpyH-1)2] as well as [Fe(X-bzimpy)2]2+ were investigated by UV-VIS and FT-IR, Moessbauer spectroscopy. Quantum-mechanical calculations of the different species were performed and the derived parameters found to be in good agreement with the measured ones. The solid deprotonated complexes, showing in general thermal induced spincrossover, are predominantly at their low-spin (LS) state at room temperature in solid state. In contrast, a pronounced spin-crossover can be observed in methanolic solution. Thermodynamic parameters for [Fe(II-bzimpy)2]2+ and [Fe(H-bzimpyH-1)2] are derived in methanolic solution as ΔH and ΔS as 22.7 ± 0.6, 25.6 ± 1.2 kJ/mol and 85.1 ± 2.1, 92.8 ± 4.3 J/K/mol, respectively. In solid state for [Fe(H-bzimpy)2]2+, ΔH and ΔS were 13.3 ± 2.4 kJ/mol and 42.5 ± 8.6 J/K/mol, respectively.
KW - 4-X-2,6-bis-(benzimidazol-2′-yl)-pyridine
KW - Deprotonation
KW - Spin-transition
KW - Thermodynamic parameters
KW - [Fe(X-bzimpyH)]
UR - http://www.scopus.com/inward/record.url?scp=84961979421&partnerID=8YFLogxK
U2 - 10.1016/S0924-2031(96)00042-2
DO - 10.1016/S0924-2031(96)00042-2
M3 - Article
AN - SCOPUS:84961979421
VL - 14
SP - 95
EP - 104
JO - Vibrational spectroscopy
JF - Vibrational spectroscopy
SN - 0924-2031
IS - 1
ER -