Magnetic properties and EPR spectra of [Cu(L-arginine)2](NO3)2·3H2O

Magnetic and EPR data have been collected for complex [Cu(L-Arg)2](NO3)2·3H2O (Arg=arginine). Magnetic susceptibility χ in the temperature range 2-160 K, and a magnetization isotherm at T=2.29(1) K with magnetic fields between 0 and 9 T were measured. The observed variation of χT with T indicates pr...

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Detalles Bibliográficos
Autor principal:	Perec, Mireille
Publicado:	2007
Materias:	D. Electron paramagnetic resonance D. Magnetic properties Antiferromagnetic interactions Magnetic measurements Magnetization isotherm Molecular field model Antiferromagnetism Magnetic couplings Magnetic fields Magnetization Paramagnetic resonance Copper compounds
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223697_v68_n8_p1533_Gerard http://hdl.handle.net/20.500.12110/paper_00223697_v68_n8_p1533_Gerard
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00223697_v68_n8_p1533_Gerard
record_format	dspace
spelling	paper:paper_00223697_v68_n8_p1533_Gerard2023-06-08T14:50:18Z Magnetic properties and EPR spectra of [Cu(L-arginine)2](NO3)2·3H2O Perec, Mireille D. Electron paramagnetic resonance D. Magnetic properties Antiferromagnetic interactions Magnetic measurements Magnetization isotherm Molecular field model Antiferromagnetism Magnetic couplings Magnetic fields Magnetization Paramagnetic resonance Copper compounds Magnetic and EPR data have been collected for complex [Cu(L-Arg)2](NO3)2·3H2O (Arg=arginine). Magnetic susceptibility χ in the temperature range 2-160 K, and a magnetization isotherm at T=2.29(1) K with magnetic fields between 0 and 9 T were measured. The observed variation of χT with T indicates predominant antiferromagnetic interactions between Cu(II) ions coupled in 1D chains along the b axis. Fitting a molecular field model to the susceptibility data allows to evaluate g=2.10(1) for the average g-factor and J=-0.42(6) cm-1 for the nearest neighbor exchange coupling (defined as Hex = - ∑ Jij Si · Sj). This coupling is assigned to syn-anti equatorial-apical carboxylate bridges connecting Cu(II) ion neighbors at 5.682 Å, with a total bond length of 6.989 Å and is consistent with the magnetization isotherm results. It is discussed and compared with couplings observed in other compounds with similar exchange bridges. EPR spectra at 9.77 were obtained in powder samples and at 9.77 and at 34.1 GHz in the three orthogonal planes of single crystals. At both microwave frequencies, and for all magnetic field orientations a single signal arising from the collapse due to exchange interaction of resonances corresponding to two rotated Cu(II) sites is observed. From the EPR results the molecular g-tensors corresponding to the two copper sites in the unit cell were evaluated, allowing an estimated lower limit \|J \|>0.1 cm-1 for the exchange interaction between Cu(II) neighbors, consistent with the magnetic measurements. The observed angular variation of the line width is attributed to dipolar coupling between Cu(II) ions in the lattice. © 2007 Elsevier Ltd. All rights reserved. Fil:Perec, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2007 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223697_v68_n8_p1533_Gerard http://hdl.handle.net/20.500.12110/paper_00223697_v68_n8_p1533_Gerard
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	D. Electron paramagnetic resonance D. Magnetic properties Antiferromagnetic interactions Magnetic measurements Magnetization isotherm Molecular field model Antiferromagnetism Magnetic couplings Magnetic fields Magnetization Paramagnetic resonance Copper compounds
spellingShingle	D. Electron paramagnetic resonance D. Magnetic properties Antiferromagnetic interactions Magnetic measurements Magnetization isotherm Molecular field model Antiferromagnetism Magnetic couplings Magnetic fields Magnetization Paramagnetic resonance Copper compounds Perec, Mireille Magnetic properties and EPR spectra of [Cu(L-arginine)2](NO3)2·3H2O
topic_facet	D. Electron paramagnetic resonance D. Magnetic properties Antiferromagnetic interactions Magnetic measurements Magnetization isotherm Molecular field model Antiferromagnetism Magnetic couplings Magnetic fields Magnetization Paramagnetic resonance Copper compounds
description	Magnetic and EPR data have been collected for complex [Cu(L-Arg)2](NO3)2·3H2O (Arg=arginine). Magnetic susceptibility χ in the temperature range 2-160 K, and a magnetization isotherm at T=2.29(1) K with magnetic fields between 0 and 9 T were measured. The observed variation of χT with T indicates predominant antiferromagnetic interactions between Cu(II) ions coupled in 1D chains along the b axis. Fitting a molecular field model to the susceptibility data allows to evaluate g=2.10(1) for the average g-factor and J=-0.42(6) cm-1 for the nearest neighbor exchange coupling (defined as Hex = - ∑ Jij Si · Sj). This coupling is assigned to syn-anti equatorial-apical carboxylate bridges connecting Cu(II) ion neighbors at 5.682 Å, with a total bond length of 6.989 Å and is consistent with the magnetization isotherm results. It is discussed and compared with couplings observed in other compounds with similar exchange bridges. EPR spectra at 9.77 were obtained in powder samples and at 9.77 and at 34.1 GHz in the three orthogonal planes of single crystals. At both microwave frequencies, and for all magnetic field orientations a single signal arising from the collapse due to exchange interaction of resonances corresponding to two rotated Cu(II) sites is observed. From the EPR results the molecular g-tensors corresponding to the two copper sites in the unit cell were evaluated, allowing an estimated lower limit \|J \|>0.1 cm-1 for the exchange interaction between Cu(II) neighbors, consistent with the magnetic measurements. The observed angular variation of the line width is attributed to dipolar coupling between Cu(II) ions in the lattice. © 2007 Elsevier Ltd. All rights reserved.
author	Perec, Mireille
author_facet	Perec, Mireille
author_sort	Perec, Mireille
title	Magnetic properties and EPR spectra of [Cu(L-arginine)2](NO3)2·3H2O
title_short	Magnetic properties and EPR spectra of [Cu(L-arginine)2](NO3)2·3H2O
title_full	Magnetic properties and EPR spectra of [Cu(L-arginine)2](NO3)2·3H2O
title_fullStr	Magnetic properties and EPR spectra of [Cu(L-arginine)2](NO3)2·3H2O
title_full_unstemmed	Magnetic properties and EPR spectra of [Cu(L-arginine)2](NO3)2·3H2O
title_sort	magnetic properties and epr spectra of [cu(l-arginine)2](no3)2·3h2o
publishDate	2007
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223697_v68_n8_p1533_Gerard http://hdl.handle.net/20.500.12110/paper_00223697_v68_n8_p1533_Gerard
work_keys_str_mv	AT perecmireille magneticpropertiesandeprspectraofcularginine2no323h2o
_version_	1768542874578714624

Magnetic properties and EPR spectra of [Cu(L-arginine)2](NO3)2·3H2O

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