A two-dimensional (magnetic field and concentration) electron paramagnetic resonance method for analysis of multispecies complex equilibrium systems. Information content of EPR spectra

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Abstract

A two-dimensional simulation method has been developed for the interpretation of electron paramagnetic resonance (EPR) spectra consisting of a multitude of strongly overlapping signal components. The set of EPR spectra for complex equilibrium systems is analyzed simultaneously as a function of metal and ligand concentrations and pH. The formation constants of the various species are adjusted together with the magnetic parameters of the component EPR spectra. At most 10 EPR-active and 5 EPR-silent species can be involved to simulate a maximum of 36 experimental spectra, while the number of adjusted parameters is at most 100. Statistical parameters are suggested to give the confidence intervals for parameter estimation and to distinguish alternative speciation models. The efficiency of the program is demonstrated for the copper(II)-L-asparagine system, in which 10 species, including 3 pairs of isomers, are characterized with magnetic parameters and formation constants. On the basis of the magnetic parameters, a structural assignment is made for the detected species. The two-dimensional approach can also supply the formation constant of the EPR-silent species, as demonstrated for the copper(II)-glycyl-L-serine system.

Original languageEnglish
Pages (from-to)7646-7654
Number of pages9
JournalJournal of the American Chemical Society
Volume123
Issue number31
DOIs
Publication statusPublished - 2001

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Electron Spin Resonance Spectroscopy
Magnetic Fields
Paramagnetic resonance
Magnetic fields
Organizational Efficiency
Copper
Asparagine
Isomers
Parameter estimation
Metals
Ligands
Confidence Intervals

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

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title = "A two-dimensional (magnetic field and concentration) electron paramagnetic resonance method for analysis of multispecies complex equilibrium systems. Information content of EPR spectra",
abstract = "A two-dimensional simulation method has been developed for the interpretation of electron paramagnetic resonance (EPR) spectra consisting of a multitude of strongly overlapping signal components. The set of EPR spectra for complex equilibrium systems is analyzed simultaneously as a function of metal and ligand concentrations and pH. The formation constants of the various species are adjusted together with the magnetic parameters of the component EPR spectra. At most 10 EPR-active and 5 EPR-silent species can be involved to simulate a maximum of 36 experimental spectra, while the number of adjusted parameters is at most 100. Statistical parameters are suggested to give the confidence intervals for parameter estimation and to distinguish alternative speciation models. The efficiency of the program is demonstrated for the copper(II)-L-asparagine system, in which 10 species, including 3 pairs of isomers, are characterized with magnetic parameters and formation constants. On the basis of the magnetic parameters, a structural assignment is made for the detected species. The two-dimensional approach can also supply the formation constant of the EPR-silent species, as demonstrated for the copper(II)-glycyl-L-serine system.",
author = "A. Rockenbauer and T. Szab{\'o}-Pl{\'a}nka and Z. {\'A}rkosi and L. Korecz",
year = "2001",
doi = "10.1021/ja0102888",
language = "English",
volume = "123",
pages = "7646--7654",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "31",

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TY - JOUR

T1 - A two-dimensional (magnetic field and concentration) electron paramagnetic resonance method for analysis of multispecies complex equilibrium systems. Information content of EPR spectra

AU - Rockenbauer, A.

AU - Szabó-Plánka, T.

AU - Árkosi, Z.

AU - Korecz, L.

PY - 2001

Y1 - 2001

N2 - A two-dimensional simulation method has been developed for the interpretation of electron paramagnetic resonance (EPR) spectra consisting of a multitude of strongly overlapping signal components. The set of EPR spectra for complex equilibrium systems is analyzed simultaneously as a function of metal and ligand concentrations and pH. The formation constants of the various species are adjusted together with the magnetic parameters of the component EPR spectra. At most 10 EPR-active and 5 EPR-silent species can be involved to simulate a maximum of 36 experimental spectra, while the number of adjusted parameters is at most 100. Statistical parameters are suggested to give the confidence intervals for parameter estimation and to distinguish alternative speciation models. The efficiency of the program is demonstrated for the copper(II)-L-asparagine system, in which 10 species, including 3 pairs of isomers, are characterized with magnetic parameters and formation constants. On the basis of the magnetic parameters, a structural assignment is made for the detected species. The two-dimensional approach can also supply the formation constant of the EPR-silent species, as demonstrated for the copper(II)-glycyl-L-serine system.

AB - A two-dimensional simulation method has been developed for the interpretation of electron paramagnetic resonance (EPR) spectra consisting of a multitude of strongly overlapping signal components. The set of EPR spectra for complex equilibrium systems is analyzed simultaneously as a function of metal and ligand concentrations and pH. The formation constants of the various species are adjusted together with the magnetic parameters of the component EPR spectra. At most 10 EPR-active and 5 EPR-silent species can be involved to simulate a maximum of 36 experimental spectra, while the number of adjusted parameters is at most 100. Statistical parameters are suggested to give the confidence intervals for parameter estimation and to distinguish alternative speciation models. The efficiency of the program is demonstrated for the copper(II)-L-asparagine system, in which 10 species, including 3 pairs of isomers, are characterized with magnetic parameters and formation constants. On the basis of the magnetic parameters, a structural assignment is made for the detected species. The two-dimensional approach can also supply the formation constant of the EPR-silent species, as demonstrated for the copper(II)-glycyl-L-serine system.

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U2 - 10.1021/ja0102888

DO - 10.1021/ja0102888

M3 - Article

VL - 123

SP - 7646

EP - 7654

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 31

ER -