Characterisation of the Fe(III):H+ Defect Centre in Natural Amethyst

AbstractA natural single crystal of amethyst was investigated by means of continuous-wave and pulsed Electron Paramagnetic Resonance (EPR), with the aim of structurally characterizing the substitutional S2 Fe(III):H+ centre. In this centre, Fe(III) replaces Si(IV) in the tetrahedral site, whereas H+ is coupled to Fe(III) to maintain the charge balance. The spectroscopic investigations, mainly the interpretation of the Electron Spin Echo Envelope Modulation, allowed a detailed localisation of the proton to be obtained. H+ occurs in the channels crossing the crystal parallel to the crystallographic c axis, in a largely eccentric position. The Fe(III)-H+ distance, evaluated in 2.70 Å, is found associated with a non-negligible isotropic hyperfine coupling, which can be linked to the relative stability of the S2 centre in natural amethyst.

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Structural, electron paramagnetic resonance and electron spin echo envelope modulation studies of oxovanadium(iv)–amidate compounds containing monoanionic axial ligands: effect on the 51V-hyperfine coupling constants

Chemical Communications ◽

10.1039/b000399i ◽

2000 ◽

pp. 601-602 ◽

Cited By ~ 8

Author(s):

Evangelos J. Tolis ◽

Kalliopi D. Soulti ◽

Themistoklis A. Kabanos ◽

Catherine P. Raptopoulou ◽

Aris Terzis ◽

...

Keyword(s):

Electron Paramagnetic Resonance ◽

Electron Spin ◽

Hyperfine Coupling ◽

Spin Echo ◽

Electron Spin Echo ◽

Coupling Constants ◽

Paramagnetic Resonance ◽

Hyperfine Coupling Constants ◽

Axial Ligands ◽

Electron Paramagnetic

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Copper(II) ionic species in CuII-exchanged K-offretite aluminosilicate and comparison with CuII-exchanged K-offretite gallosilicate determined by electron paramagnetic resonance and electron spin echo modulation spectroscopies

Journal of the Chemical Society Faraday Transactions ◽

10.1039/a606011k ◽

1997 ◽

Vol 93 (6) ◽

pp. 1225-1231 ◽

Cited By ~ 5

Author(s):

Jong-Sung Yu ◽

Jang Whan Ryoo ◽

Chul Wee Lee ◽

Sun Jin Kim ◽

Suk Bong Hong ◽

...

Keyword(s):

Electron Paramagnetic Resonance ◽

Electron Spin ◽

Spin Echo ◽

Electron Spin Echo ◽

Ionic Species ◽

Paramagnetic Resonance ◽

Electron Paramagnetic ◽

Electron Spin Echo Modulation

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An EPR Study on the Interaction between the Cu(I) Metal Binding Domains of ATP7B and the Atox1 Metallochaperone

International Journal of Molecular Sciences ◽

10.3390/ijms21155536 ◽

2020 ◽

Vol 21 (15) ◽

pp. 5536

Author(s):

Michael Zaccak ◽

Zena Qasem ◽

Lada Gevorkyan-Airapetov ◽

Sharon Ruthstein

Keyword(s):

Metal Binding ◽

Continuous Wave ◽

Regulation System ◽

Membrane Domain ◽

Paramagnetic Resonance ◽

Copper Trafficking ◽

Binding Domains ◽

Metal Binding Domain ◽

Pulsed Electron Paramagnetic Resonance ◽

Electron Paramagnetic

Copper’s essentiality and toxicity mean it requires a sophisticated regulation system for its acquisition, cellular distribution and excretion, which until now has remained elusive. Herein, we applied continuous wave (CW) and pulsed electron paramagnetic resonance (EPR) spectroscopy in solution to resolve the copper trafficking mechanism in humans, by considering the route travelled by Cu(I) from the metallochaperone Atox1 to the metal binding domains of ATP7B. Our study revealed that Cu(I) is most likely mediated by the binding of the Atox1 monomer to metal binding domain 1 (MBD1) and MBD4 of ATP7B in the final part of its extraction pathway, while the other MBDs mediate this interaction and participate in copper transfer between the various MBDs to the ATP7B membrane domain. This research also proposes that MBD1-3 and MBD4-6 act as two independent units.

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Axial Ligation in Blue-Copper Proteins. A W-Band Electron Spin Echo Detected Electron Paramagnetic Resonance Study of the Azurin Mutant M121H

Journal of the American Chemical Society ◽

10.1021/ja993357f ◽

2000 ◽

Vol 122 (10) ◽

pp. 2322-2328 ◽

Cited By ~ 21

Author(s):

M. van Gastel ◽

G. W. Canters ◽

H. Krupka ◽

A. Messerschmidt ◽

E. C. de Waal ◽

...

Keyword(s):

Electron Paramagnetic Resonance ◽

Spin Echo ◽

Electron Paramagnetic Resonance Study ◽

Electron Spin Echo ◽

Copper Proteins ◽

Blue Copper Proteins ◽

Paramagnetic Resonance ◽

Axial Ligation ◽

W Band ◽

Electron Paramagnetic

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Nitrogen Centers in Nanodiamonds: EPR Studies

Materials Science Forum ◽

10.4028/www.scientific.net/msf.645-648.1239 ◽

2010 ◽

Vol 645-648 ◽

pp. 1239-1242 ◽

Cited By ~ 1

Author(s):

Alexandra A. Soltamova ◽

P.G. Baranov ◽

Ivan V. Ilyin ◽

A.Y. Vul' ◽

S.V. Kidalov ◽

...

Keyword(s):

Spin Echo ◽

Natural Diamond ◽

Electron Spin Echo ◽

Atomic Nitrogen ◽

Paramagnetic Resonance ◽

W Band ◽

High Pressure High Temperature ◽

X Band ◽

Epr Signal ◽

Electron Paramagnetic

Electron paramagnetic resonance (EPR) and electron spin echo (ESE) at X-band (9.4 GHz) and W-band (94 GHz) have been used to study defects in natural diamond nanocrystals, detonation nanodiamond (ND) with a size of  4.5 nm and detonation ND after high-pressure high-temperature (HTHP) sintering with a size of  8.5 nm. Based on identification of atomic nitrogen centers N0 and nitrogen pairs N2+ detected by means of the high frequency EPR and ESE in natural diamond nanocrystals, atomic nitrogen centers N0 have been discovered in nanodiamond core in detonation ND and detonation ND after sintering. In addition EPR signal of multi-vacancy centers with spin 3/2 seems to be observed in diamond core of detonation ND.

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