Charge-transfer optical spectra, electron paramagnetic resonance, and redox potentials of cytochromes

Biochemistry ◽  
1984 ◽  
Vol 23 (6) ◽  
pp. 1081-1084 ◽  
Author(s):  
Abel Schejter ◽  
William A. Eaton
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Charge Transfer ◽  
Optical Spectra ◽  
Redox Potentials ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

On The EPR Parameters of Divalent Cobalt in ZnX (X = S, Se, Te) And CdTe

2004 ◽  
Vol 59 (12) ◽  
pp. 938-942 ◽  
Author(s):  
Shao-Yi Wu ◽  
Hui-Ning Dong
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Charge Transfer ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Paramagnetic Resonance ◽  
A Value ◽  
Epr Parameters ◽  
Divalent Cobalt ◽  
Structure Constants ◽  
Electron Paramagnetic

The electron paramagnetic resonance (EPR) parameters g and the hyperfine structure constants A of Co2+ in ZnX (X = S, Se, Te) and CdTe are studied, using the perturbation formulas of the EPR parameters for a 3d7 ion in tetrahedra based on two mechanism models. In these formulas, both the contributions from the conventional crystal-field (CF) mechanism and those from the charge-transfer (CT) mechanism are taken into account. According to the investigations, the sign of the g-shift ΔgCT from the CT mechanism is the same as ΔgCF from the CF mechanism, whereas the contributions to the A value from the CF and CT mechanisms have opposite signs. Particularly, the contributions to the EPR parameters from the CT mechanism increase rapidly with increase of the spin-orbit coupling coefficient of the ligand and the covalency effect of the systems, i. e. S2− < Se2− < Te2−.

Glutaraldehyde effect on hemoglobin: evidence for an ion environment modification based on electron paramagnetic resonance and Mossbauer spectroscopies

1990 ◽  
Vol 68 (4) ◽  
pp. 813-818 ◽  
Author(s):  
Alain Chevalier ◽  
Didiers Guillochon ◽  
Naima Nedjar ◽  
Jean Marie Piot ◽  
Mokambes Waran Vijayalakshmi ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Functional Properties ◽  
Oxygen Affinity ◽  
Blood Substitute ◽  
Blood Substitutes ◽  
Point Of View ◽  
Cross Linking ◽  
Redox Potentials ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

Glutaraldehyde is a widely used reagent for hemoglobin cross-linking in blood substitutes research. However, hemoglobin polymerization by glutaraldehyde involves modifications of its functional properties, such as oxygen affinity, redox potentials, and autoxidation kinetics. The aim of this article is to investigate, by electron paramagnetic resonance and Mossbauer spectroscopies, the changes that occur in the iron environment after glutaraldehyde cross-linking. Spectrometric studies were performed with native hemoglobin and hemoglobin cross-linked as soluble and insoluble polymers. Spectrometry data comparison with glutaraldehyde-modified hemoglobin functional properties allows to interpret from a structural point of view that glutaraldehyde action occurs as a decrease of the O—N(F8His) distance, an increase of the Fe—N(F8His) bond length, and the decrease of the distal-side steric hindrance.Key words: hemoglobin, glutaraldehyde, Mossbauer spectroscopy, electron paramagnetic resonance, blood substitute.

Theoretical investigations of electron paramagnetic resonancegfactors in ZnSe:Ti2+, CdTe:Ti2+and ZnSe:V3+crystals

2012 ◽  
Vol 45 (5) ◽  
pp. 972-975
Author(s):  
Lianxuan Zhu ◽  
Minjie Wang
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Charge Transfer ◽  
Coupling Effect ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Paramagnetic Resonance ◽  
Theoretical Investigations ◽  
The One ◽  
Electron Paramagnetic

The electron paramagnetic resonance (EPR)g-factor formulas are constructed for ZnSe:Ti2+, CdTe:Ti2+and ZnSe:V3+crystals based on the contributions of the charge-transfer levels and the spin-orbit coupling effect of the central ion and the ligands. The EPRgfactors are calculated from these formulas, and the calculated values agree well with the experimental ones. The contribution rates of the charge-transfer levels are 10.1, 7.6 and 24.9% for ZnSe:Ti2+, CdTe:Ti2+and ZnSe:V3+crystals, respectively. Thegfactors obtained from the one-spin-orbit-parameter model are also given for comparison.

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