Electronic and magnetic properties of iron (III) dinuclear complexes with carboxylate bridges

Verónica Paredes-García, Ramón O. Latorre, Evgenia Spodine

Resultado de la investigación: Article

12 Citas (Scopus)

Resumen

A series of dinuclear iron (III) complexes with carboxylate bridges, of the type [Fe2L2(H20)4](NO 3)2(H2O)m (m=1-3), where L=Schiff base derived from L-α-amino acids and salicylaldehyde have been prepared and characterised by different spectroscopic techniques, magnetic susceptibility, conductivity, and electrochemical measurements. The dimeric iron complexes contain hexacoordinated iron (III), with the metal ion surrounded by water molecules, the salicylidenimine ligand, and the bridging carboxylate groups. The inequivalence of the iron atoms is detected by Mössbauer spectroscopy and this is reflected by the presence of two overlapping quadrupole doublets (δ1∼0.52-0.67 mms-1, δ2∼0.64-0.80 mms-1, ΔEQ1∼0. 38-0.80 mms-1, and ΔEQ2 (∼0.68-1.01 mms -1), with an approximate intensity ratio of 1:1 for all complexes. The magnetic susceptibilities of the complexes were determined over the temperature interval 5-300 K and revealed a decrease in the effective magnetic moment with decreasing temperature. The plots of the reciprocal of the molar susceptibility versus temperature indicate that the two iron (III) ions are very weakly antiferromagnetically coupled (-J∼0.09-0.21 cm-1). Electrochemical studies show that the first two peaks can be assigned to two consecutive one-electron reduction process, affording FeIIFe III and FeIIFeII. The comproportionation constant Kc at 298 K is in the 5.3×103-2. 5×104 range. The values obtained are in agreement with an intermediate electron coupling between redox sites.

Idioma originalEnglish
Páginas (desde-hasta)1869-1876
Número de páginas8
PublicaciónPolyhedron
Volumen23
N.º11
DOI
EstadoPublished - 8 jul 2004

Huella dactilar

Electronic properties
carboxylates
Magnetic properties
Iron
magnetic properties
iron
electronics
Magnetic susceptibility
magnetic permeability
Schiff Bases
Electrons
Magnetic moments
Temperature
imines
Metal ions
temperature
amino acids
Amino acids
metal ions
electrons

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Citar esto

Paredes-García, Verónica ; Latorre, Ramón O. ; Spodine, Evgenia. / Electronic and magnetic properties of iron (III) dinuclear complexes with carboxylate bridges. En: Polyhedron. 2004 ; Vol. 23, N.º 11. pp. 1869-1876.
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title = "Electronic and magnetic properties of iron (III) dinuclear complexes with carboxylate bridges",
abstract = "A series of dinuclear iron (III) complexes with carboxylate bridges, of the type [Fe2L2(H20)4](NO 3)2(H2O)m (m=1-3), where L=Schiff base derived from L-α-amino acids and salicylaldehyde have been prepared and characterised by different spectroscopic techniques, magnetic susceptibility, conductivity, and electrochemical measurements. The dimeric iron complexes contain hexacoordinated iron (III), with the metal ion surrounded by water molecules, the salicylidenimine ligand, and the bridging carboxylate groups. The inequivalence of the iron atoms is detected by M{\"o}ssbauer spectroscopy and this is reflected by the presence of two overlapping quadrupole doublets (δ1∼0.52-0.67 mms-1, δ2∼0.64-0.80 mms-1, ΔEQ1∼0. 38-0.80 mms-1, and ΔEQ2 (∼0.68-1.01 mms -1), with an approximate intensity ratio of 1:1 for all complexes. The magnetic susceptibilities of the complexes were determined over the temperature interval 5-300 K and revealed a decrease in the effective magnetic moment with decreasing temperature. The plots of the reciprocal of the molar susceptibility versus temperature indicate that the two iron (III) ions are very weakly antiferromagnetically coupled (-J∼0.09-0.21 cm-1). Electrochemical studies show that the first two peaks can be assigned to two consecutive one-electron reduction process, affording FeIIFe III and FeIIFeII. The comproportionation constant Kc at 298 K is in the 5.3×103-2. 5×104 range. The values obtained are in agreement with an intermediate electron coupling between redox sites.",
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Electronic and magnetic properties of iron (III) dinuclear complexes with carboxylate bridges. / Paredes-García, Verónica; Latorre, Ramón O.; Spodine, Evgenia.

En: Polyhedron, Vol. 23, N.º 11, 08.07.2004, p. 1869-1876.

Resultado de la investigación: Article

TY - JOUR

T1 - Electronic and magnetic properties of iron (III) dinuclear complexes with carboxylate bridges

AU - Paredes-García, Verónica

AU - Latorre, Ramón O.

AU - Spodine, Evgenia

PY - 2004/7/8

Y1 - 2004/7/8

N2 - A series of dinuclear iron (III) complexes with carboxylate bridges, of the type [Fe2L2(H20)4](NO 3)2(H2O)m (m=1-3), where L=Schiff base derived from L-α-amino acids and salicylaldehyde have been prepared and characterised by different spectroscopic techniques, magnetic susceptibility, conductivity, and electrochemical measurements. The dimeric iron complexes contain hexacoordinated iron (III), with the metal ion surrounded by water molecules, the salicylidenimine ligand, and the bridging carboxylate groups. The inequivalence of the iron atoms is detected by Mössbauer spectroscopy and this is reflected by the presence of two overlapping quadrupole doublets (δ1∼0.52-0.67 mms-1, δ2∼0.64-0.80 mms-1, ΔEQ1∼0. 38-0.80 mms-1, and ΔEQ2 (∼0.68-1.01 mms -1), with an approximate intensity ratio of 1:1 for all complexes. The magnetic susceptibilities of the complexes were determined over the temperature interval 5-300 K and revealed a decrease in the effective magnetic moment with decreasing temperature. The plots of the reciprocal of the molar susceptibility versus temperature indicate that the two iron (III) ions are very weakly antiferromagnetically coupled (-J∼0.09-0.21 cm-1). Electrochemical studies show that the first two peaks can be assigned to two consecutive one-electron reduction process, affording FeIIFe III and FeIIFeII. The comproportionation constant Kc at 298 K is in the 5.3×103-2. 5×104 range. The values obtained are in agreement with an intermediate electron coupling between redox sites.

AB - A series of dinuclear iron (III) complexes with carboxylate bridges, of the type [Fe2L2(H20)4](NO 3)2(H2O)m (m=1-3), where L=Schiff base derived from L-α-amino acids and salicylaldehyde have been prepared and characterised by different spectroscopic techniques, magnetic susceptibility, conductivity, and electrochemical measurements. The dimeric iron complexes contain hexacoordinated iron (III), with the metal ion surrounded by water molecules, the salicylidenimine ligand, and the bridging carboxylate groups. The inequivalence of the iron atoms is detected by Mössbauer spectroscopy and this is reflected by the presence of two overlapping quadrupole doublets (δ1∼0.52-0.67 mms-1, δ2∼0.64-0.80 mms-1, ΔEQ1∼0. 38-0.80 mms-1, and ΔEQ2 (∼0.68-1.01 mms -1), with an approximate intensity ratio of 1:1 for all complexes. The magnetic susceptibilities of the complexes were determined over the temperature interval 5-300 K and revealed a decrease in the effective magnetic moment with decreasing temperature. The plots of the reciprocal of the molar susceptibility versus temperature indicate that the two iron (III) ions are very weakly antiferromagnetically coupled (-J∼0.09-0.21 cm-1). Electrochemical studies show that the first two peaks can be assigned to two consecutive one-electron reduction process, affording FeIIFe III and FeIIFeII. The comproportionation constant Kc at 298 K is in the 5.3×103-2. 5×104 range. The values obtained are in agreement with an intermediate electron coupling between redox sites.

KW - Bridging

KW - Carboxylate

KW - Complexes

KW - Dinuclear

KW - Iron (III)

KW - Mössbauer

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U2 - 10.1016/j.poly.2004.03.024

DO - 10.1016/j.poly.2004.03.024

M3 - Article

AN - SCOPUS:3242801242

VL - 23

SP - 1869

EP - 1876

JO - Polyhedron

JF - Polyhedron

SN - 0277-5387

IS - 11

ER -