Consistent simulation of X- and Q-band EPR spectra of an unsymmetric dinuclear Mn2 II, III complex

Ping Huang, Nizamuddin Shaikh, Magnus F. Anderlund, Stenbjörn Styring, Leif Hammarström

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Simulation of X- and Q-band electron paramagnetic resonance (EPR) spectra of an unsymmetric dinuclear [ Mn2 II, III L ( μ - OAc )2 ] ClO4 complex (1), (L is the dianion of 2-{[N,N-bis(2-pyridylmethyl)amino]methyl}-6-{[N-(3,5-di-tert-butyl-2-hyd roxybenzyl)-N-(2-pyridylmethyl)amino]methyl}-4-methylphenol) was performed using one consistent set of simulation parameters. Rhombic g-tensors and hyperfine tensors were necessary to obtain satisfactory simulation of the EPR spectra. The anisotropy of the effective hyperfine tensors of each individual 55Mn ion was further analyzed in terms of intrinsic hyperfine tensors. Detailed analysis shows that the hyperfine anisotropy of the MnIII ion is a result of the Jahn-Teller effect and thus an inherent character. In contrast, the anomalous hyperfine anisotropy of the MnII ion is attributed as being transferred from the MnIII ion through the spin exchange interaction. The anisotropy parameter for the MnII is deduced as DII = -1.26 ± 0.2 cm-1. This is the first reported DII value for a MnII ion in a weakly exchange coupled mixed-valence Mn2 II, III complex with a bis-μ-acetato-bridge. The dxy 1 dyz 1 dzx 1 d x2 - y21 electronic configuration of the MnIII ion in 1 is revealed by the negative sign of its intrinsic hyperfine tensor anisotropy, ΔaIII = az - ax,y = -46 cm-1. Lower spectral resolution of the Q-band EPR spectrum as compared to the X-band EPR spectrum is associated to large line width broadening of the x- and y-components in contrast to the z-component. The origins of the unequal distribution of line width between the z- and x-, y-components are discussed.

Original languageEnglish
Pages (from-to)1139-1146
Number of pages8
JournalJournal of Inorganic Biochemistry
Volume100
Issue number5-6
DOIs
Publication statusPublished - May 2006

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Electron Spin Resonance Spectroscopy
Anisotropy
Paramagnetic resonance
Tensors
Ions
Linewidth
Jahn-Teller effect
Spectral resolution
Exchange interactions

Keywords

  • Dinuclear Mn
  • Electron configuration
  • EPR simulation
  • g-Tensor
  • Hyperfine tensor
  • X- and Q-band EPR
  • Zero field splitting

ASJC Scopus subject areas

  • Biochemistry
  • Inorganic Chemistry

Cite this

Consistent simulation of X- and Q-band EPR spectra of an unsymmetric dinuclear Mn2 II, III complex. / Huang, Ping; Shaikh, Nizamuddin; Anderlund, Magnus F.; Styring, Stenbjörn; Hammarström, Leif.

In: Journal of Inorganic Biochemistry, Vol. 100, No. 5-6, 05.2006, p. 1139-1146.

Research output: Contribution to journalArticle

Huang, Ping ; Shaikh, Nizamuddin ; Anderlund, Magnus F. ; Styring, Stenbjörn ; Hammarström, Leif. / Consistent simulation of X- and Q-band EPR spectra of an unsymmetric dinuclear Mn2 II, III complex. In: Journal of Inorganic Biochemistry. 2006 ; Vol. 100, No. 5-6. pp. 1139-1146.
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abstract = "Simulation of X- and Q-band electron paramagnetic resonance (EPR) spectra of an unsymmetric dinuclear [ Mn2 II, III L ( μ - OAc )2 ] ClO4 complex (1), (L is the dianion of 2-{[N,N-bis(2-pyridylmethyl)amino]methyl}-6-{[N-(3,5-di-tert-butyl-2-hyd roxybenzyl)-N-(2-pyridylmethyl)amino]methyl}-4-methylphenol) was performed using one consistent set of simulation parameters. Rhombic g-tensors and hyperfine tensors were necessary to obtain satisfactory simulation of the EPR spectra. The anisotropy of the effective hyperfine tensors of each individual 55Mn ion was further analyzed in terms of intrinsic hyperfine tensors. Detailed analysis shows that the hyperfine anisotropy of the MnIII ion is a result of the Jahn-Teller effect and thus an inherent character. In contrast, the anomalous hyperfine anisotropy of the MnII ion is attributed as being transferred from the MnIII ion through the spin exchange interaction. The anisotropy parameter for the MnII is deduced as DII = -1.26 ± 0.2 cm-1. This is the first reported DII value for a MnII ion in a weakly exchange coupled mixed-valence Mn2 II, III complex with a bis-μ-acetato-bridge. The dxy 1 dyz 1 dzx 1 d x2 - y21 electronic configuration of the MnIII ion in 1 is revealed by the negative sign of its intrinsic hyperfine tensor anisotropy, ΔaIII = az - ax,y = -46 cm-1. Lower spectral resolution of the Q-band EPR spectrum as compared to the X-band EPR spectrum is associated to large line width broadening of the x- and y-components in contrast to the z-component. The origins of the unequal distribution of line width between the z- and x-, y-components are discussed.",
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T1 - Consistent simulation of X- and Q-band EPR spectra of an unsymmetric dinuclear Mn2 II, III complex

AU - Huang, Ping

AU - Shaikh, Nizamuddin

AU - Anderlund, Magnus F.

AU - Styring, Stenbjörn

AU - Hammarström, Leif

PY - 2006/5

Y1 - 2006/5

N2 - Simulation of X- and Q-band electron paramagnetic resonance (EPR) spectra of an unsymmetric dinuclear [ Mn2 II, III L ( μ - OAc )2 ] ClO4 complex (1), (L is the dianion of 2-{[N,N-bis(2-pyridylmethyl)amino]methyl}-6-{[N-(3,5-di-tert-butyl-2-hyd roxybenzyl)-N-(2-pyridylmethyl)amino]methyl}-4-methylphenol) was performed using one consistent set of simulation parameters. Rhombic g-tensors and hyperfine tensors were necessary to obtain satisfactory simulation of the EPR spectra. The anisotropy of the effective hyperfine tensors of each individual 55Mn ion was further analyzed in terms of intrinsic hyperfine tensors. Detailed analysis shows that the hyperfine anisotropy of the MnIII ion is a result of the Jahn-Teller effect and thus an inherent character. In contrast, the anomalous hyperfine anisotropy of the MnII ion is attributed as being transferred from the MnIII ion through the spin exchange interaction. The anisotropy parameter for the MnII is deduced as DII = -1.26 ± 0.2 cm-1. This is the first reported DII value for a MnII ion in a weakly exchange coupled mixed-valence Mn2 II, III complex with a bis-μ-acetato-bridge. The dxy 1 dyz 1 dzx 1 d x2 - y21 electronic configuration of the MnIII ion in 1 is revealed by the negative sign of its intrinsic hyperfine tensor anisotropy, ΔaIII = az - ax,y = -46 cm-1. Lower spectral resolution of the Q-band EPR spectrum as compared to the X-band EPR spectrum is associated to large line width broadening of the x- and y-components in contrast to the z-component. The origins of the unequal distribution of line width between the z- and x-, y-components are discussed.

AB - Simulation of X- and Q-band electron paramagnetic resonance (EPR) spectra of an unsymmetric dinuclear [ Mn2 II, III L ( μ - OAc )2 ] ClO4 complex (1), (L is the dianion of 2-{[N,N-bis(2-pyridylmethyl)amino]methyl}-6-{[N-(3,5-di-tert-butyl-2-hyd roxybenzyl)-N-(2-pyridylmethyl)amino]methyl}-4-methylphenol) was performed using one consistent set of simulation parameters. Rhombic g-tensors and hyperfine tensors were necessary to obtain satisfactory simulation of the EPR spectra. The anisotropy of the effective hyperfine tensors of each individual 55Mn ion was further analyzed in terms of intrinsic hyperfine tensors. Detailed analysis shows that the hyperfine anisotropy of the MnIII ion is a result of the Jahn-Teller effect and thus an inherent character. In contrast, the anomalous hyperfine anisotropy of the MnII ion is attributed as being transferred from the MnIII ion through the spin exchange interaction. The anisotropy parameter for the MnII is deduced as DII = -1.26 ± 0.2 cm-1. This is the first reported DII value for a MnII ion in a weakly exchange coupled mixed-valence Mn2 II, III complex with a bis-μ-acetato-bridge. The dxy 1 dyz 1 dzx 1 d x2 - y21 electronic configuration of the MnIII ion in 1 is revealed by the negative sign of its intrinsic hyperfine tensor anisotropy, ΔaIII = az - ax,y = -46 cm-1. Lower spectral resolution of the Q-band EPR spectrum as compared to the X-band EPR spectrum is associated to large line width broadening of the x- and y-components in contrast to the z-component. The origins of the unequal distribution of line width between the z- and x-, y-components are discussed.

KW - Dinuclear Mn

KW - Electron configuration

KW - EPR simulation

KW - g-Tensor

KW - Hyperfine tensor

KW - X- and Q-band EPR

KW - Zero field splitting

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