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Title: High-temperature spin transition in coordination compounds of iron(II) with triazoles (in Russian)

Abstract

Methods for the synthesis of the complexes FeL/sub 3/(NO/sub 3/)/sub 2/, where L = 1,2,4-triazole (TR) (I) and 4-amino-1,2,4-triazole (ATR) (II), Fe(ATR)/sub 2.5/Cl/sub 2/ x H/sub 2/O (III), and Fe(TR)/sub 2/Cl/sub 2/ (IV) have been developed. A high-temperature (340-350/sup 0/K) reversible transition of Fe/sup II/ from the low-spin (LS) state to the high-spin (HS) state has been discovered during the study of the magnetic properties of complexes I-III. The plots of the dependence of ..mu../sub eff/ on T display hysteresis. Thus, the complexes of Fe/sup II/ with triazoles comprise a new group of compounds having this special feature. Complex III has different values of ..mu../sub eff/ at 300/sup 0/K, depending on the synthesis conditions. The plots of the dependence of ..mu../sub eff/ on T for complexes I and II and for III are different. Complex IV is basically a high-spin complex with a weakly expressed dependence of ..mu../sub eff/ on T. The Moessbauer spectra for complexes I and II and for a sample of III with ..mu../sub eff/ = 0.86 Bohr magneton at 300/sup 0/K display singlet lines with a value of delta typical of Fe/sup II/ in the LS state. In the spectra of samples of III with ..mu../submore » eff/(T) = 2.05 Bohr magnetons at 300/sup 0/K there are peaks for the HS form along with the line of the LS form, the complex having two modifications in the HS form with different values of epsilon. The data form diffuse reflectance spectroscopy and the values of delta and ..mu../sub eff/ point out the octahedral coordination of Fe/sup II/, the presence of an FeN/sub 6/ chromophore in complexes I and II, and the presence of an FeN/sub 4/Cl/sub 2/ chromophore in III and IV. From an analysis of the IR spectra in the region of the torsional vibrations of the ring it follows that the ligands L are coordinated by the ring N(1) and N(2) atoms, indicating that the ligands L have bridging function.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Institute of Inorganic Chemistry, Siberian, USSR
OSTI Identifier:
6158292
Resource Type:
Journal Article
Journal Name:
Sov. J. Coordinat. Chem.; (United States)
Additional Journal Information:
Journal Volume: 12:2; Other Information: Translated from Koordinatsionnaya Khimiya, 12: No. 2, 207-215(Feb 1986)
Country of Publication:
United States
Language:
Russian
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 74 ATOMIC AND MOLECULAR PHYSICS; IRON COMPLEXES; ENERGY-LEVEL TRANSITIONS; HIGH SPIN STATES; HYPERFINE STRUCTURE; TRIAZOLES; ATOMIC MODELS; BINDING ENERGY; BOHR THEORY; CATALYTIC EFFECTS; CHEMICAL SHIFT; ELECTRONIC STRUCTURE; GAMMA SPECTRA; HYDRATES; HYSTERESIS; INFRARED SPECTRA; IRON CHLORIDES; IRON NITRATES; LATTICE VIBRATIONS; LIGANDS; MAGNETIC MOMENTS; MAGNETIC SUSCEPTIBILITY; MOESSBAUER EFFECT; MOLECULAR STRUCTURE; ORGANOMETALLIC COMPOUNDS; SYNTHESIS; TRANSITION TEMPERATURE; AZOLES; CHLORIDES; CHLORINE COMPOUNDS; COMPLEXES; ENERGY; ENERGY LEVELS; HALIDES; HALOGEN COMPOUNDS; HETEROCYCLIC COMPOUNDS; IRON COMPOUNDS; MAGNETIC PROPERTIES; MATHEMATICAL MODELS; NITRATES; NITROGEN COMPOUNDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; SPECTRA; THERMODYNAMIC PROPERTIES; TRANSITION ELEMENT COMPLEXES; TRANSITION ELEMENT COMPOUNDS; 400201* - Chemical & Physicochemical Properties; 640302 - Atomic, Molecular & Chemical Physics- Atomic & Molecular Properties & Theory

Citation Formats

Lavrenova, L G, Ikorskii, V N, Varnek, V A, Oglezneva, I M, and Larionov, S V. High-temperature spin transition in coordination compounds of iron(II) with triazoles. United States: N. p., 1986. Web.
Lavrenova, L G, Ikorskii, V N, Varnek, V A, Oglezneva, I M, & Larionov, S V. High-temperature spin transition in coordination compounds of iron(II) with triazoles. United States.
Lavrenova, L G, Ikorskii, V N, Varnek, V A, Oglezneva, I M, and Larionov, S V. 1986. "High-temperature spin transition in coordination compounds of iron(II) with triazoles". United States.
@article{osti_6158292,
title = {High-temperature spin transition in coordination compounds of iron(II) with triazoles},
author = {Lavrenova, L G and Ikorskii, V N and Varnek, V A and Oglezneva, I M and Larionov, S V},
abstractNote = {Methods for the synthesis of the complexes FeL/sub 3/(NO/sub 3/)/sub 2/, where L = 1,2,4-triazole (TR) (I) and 4-amino-1,2,4-triazole (ATR) (II), Fe(ATR)/sub 2.5/Cl/sub 2/ x H/sub 2/O (III), and Fe(TR)/sub 2/Cl/sub 2/ (IV) have been developed. A high-temperature (340-350/sup 0/K) reversible transition of Fe/sup II/ from the low-spin (LS) state to the high-spin (HS) state has been discovered during the study of the magnetic properties of complexes I-III. The plots of the dependence of ..mu../sub eff/ on T display hysteresis. Thus, the complexes of Fe/sup II/ with triazoles comprise a new group of compounds having this special feature. Complex III has different values of ..mu../sub eff/ at 300/sup 0/K, depending on the synthesis conditions. The plots of the dependence of ..mu../sub eff/ on T for complexes I and II and for III are different. Complex IV is basically a high-spin complex with a weakly expressed dependence of ..mu../sub eff/ on T. The Moessbauer spectra for complexes I and II and for a sample of III with ..mu../sub eff/ = 0.86 Bohr magneton at 300/sup 0/K display singlet lines with a value of delta typical of Fe/sup II/ in the LS state. In the spectra of samples of III with ..mu../sub eff/(T) = 2.05 Bohr magnetons at 300/sup 0/K there are peaks for the HS form along with the line of the LS form, the complex having two modifications in the HS form with different values of epsilon. The data form diffuse reflectance spectroscopy and the values of delta and ..mu../sub eff/ point out the octahedral coordination of Fe/sup II/, the presence of an FeN/sub 6/ chromophore in complexes I and II, and the presence of an FeN/sub 4/Cl/sub 2/ chromophore in III and IV. From an analysis of the IR spectra in the region of the torsional vibrations of the ring it follows that the ligands L are coordinated by the ring N(1) and N(2) atoms, indicating that the ligands L have bridging function.},
doi = {},
url = {https://www.osti.gov/biblio/6158292}, journal = {Sov. J. Coordinat. Chem.; (United States)},
number = ,
volume = 12:2,
place = {United States},
year = {1986},
month = {12}
}