Magnetism and structure in chains of copper dinuclear paddlewheel units

An anhydrous copper carboxylate compound of formula [Cu(irans-2-butenoate) 2]n has been characterized. X-ray analysis reveals a structure built by paddlewheel units bridged by pairs of Cu ⋯ O axial bonds to give infinite chains arranged In a new topological motif. Susceptibility measurements In the...

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Autor principal:	Perec, Mireille
Publicado:	2010
Materias:	butyric acid derivative copper article chemical structure chemistry electron spin resonance magnetism X ray crystallography Butyric Acids Copper Crystallography, X-Ray Electron Spin Resonance Spectroscopy Magnetics Models, Molecular Molecular Structure
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v49_n2_p695_Perec http://hdl.handle.net/20.500.12110/paper_00201669_v49_n2_p695_Perec
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00201669_v49_n2_p695_Perec
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spelling	paper:paper_00201669_v49_n2_p695_Perec2023-06-08T14:40:39Z Magnetism and structure in chains of copper dinuclear paddlewheel units Perec, Mireille butyric acid derivative copper article chemical structure chemistry electron spin resonance magnetism X ray crystallography Butyric Acids Copper Crystallography, X-Ray Electron Spin Resonance Spectroscopy Magnetics Models, Molecular Molecular Structure An anhydrous copper carboxylate compound of formula [Cu(irans-2-butenoate) 2]n has been characterized. X-ray analysis reveals a structure built by paddlewheel units bridged by pairs of Cu ⋯ O axial bonds to give infinite chains arranged In a new topological motif. Susceptibility measurements In the 10-300 K temperature range, and isothermal magnetization curves at 2, 5, 10, and 50 K with fields up to 5 T, were obtained. Electron Paramagnetic Resonance (EPR) spectra of powder samples were measured at 33.9 GHz at 300 K, and at 9.60 GHz at temperatures In the range 90 ≤ T ≤ 350 K. Fitting the susceptibility data to a chain model of alternating paddlewheel and [Cu(μ-O)2Cu] dlnuclear units yielded exchange interactions J1 = -330.6(1) cm-1 and J2 = 5.9(2) cm-1. The EPR spectra reflect the usual antlferromagnetic dinuclear behavior, with zero field splitting parameters of the excited spin triplet, D = -0.329(3) cm-1 and E ∼ 0, plus a central peak not expected for Isolated dinuclear units. We interpret this peak as arising from the stochastic spin dynamics of the chain introduced by exchange couplings between spins in neighbor dinuclear units, which averages out the zero field splitting. Interactions of the units with the rest of the chain acting as a spin bath give rise to a quantum transition between localized dinuclear states and states of the spin chain. This effect competes with the condensation of the antiferromagnetic dinuclear units into the singlet ground state, producing a characteristic temperature dependence of the shape of the powder EPR spectra. We interpret these features In terms of basic theories of magnetic resonance in coupled spin systems applied to the chain array of dinuclear units. © 2009 American Chemical Society. Fil:Perec, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2010 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v49_n2_p695_Perec http://hdl.handle.net/20.500.12110/paper_00201669_v49_n2_p695_Perec
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	butyric acid derivative copper article chemical structure chemistry electron spin resonance magnetism X ray crystallography Butyric Acids Copper Crystallography, X-Ray Electron Spin Resonance Spectroscopy Magnetics Models, Molecular Molecular Structure
spellingShingle	butyric acid derivative copper article chemical structure chemistry electron spin resonance magnetism X ray crystallography Butyric Acids Copper Crystallography, X-Ray Electron Spin Resonance Spectroscopy Magnetics Models, Molecular Molecular Structure Perec, Mireille Magnetism and structure in chains of copper dinuclear paddlewheel units
topic_facet	butyric acid derivative copper article chemical structure chemistry electron spin resonance magnetism X ray crystallography Butyric Acids Copper Crystallography, X-Ray Electron Spin Resonance Spectroscopy Magnetics Models, Molecular Molecular Structure
description	An anhydrous copper carboxylate compound of formula [Cu(irans-2-butenoate) 2]n has been characterized. X-ray analysis reveals a structure built by paddlewheel units bridged by pairs of Cu ⋯ O axial bonds to give infinite chains arranged In a new topological motif. Susceptibility measurements In the 10-300 K temperature range, and isothermal magnetization curves at 2, 5, 10, and 50 K with fields up to 5 T, were obtained. Electron Paramagnetic Resonance (EPR) spectra of powder samples were measured at 33.9 GHz at 300 K, and at 9.60 GHz at temperatures In the range 90 ≤ T ≤ 350 K. Fitting the susceptibility data to a chain model of alternating paddlewheel and [Cu(μ-O)2Cu] dlnuclear units yielded exchange interactions J1 = -330.6(1) cm-1 and J2 = 5.9(2) cm-1. The EPR spectra reflect the usual antlferromagnetic dinuclear behavior, with zero field splitting parameters of the excited spin triplet, D = -0.329(3) cm-1 and E ∼ 0, plus a central peak not expected for Isolated dinuclear units. We interpret this peak as arising from the stochastic spin dynamics of the chain introduced by exchange couplings between spins in neighbor dinuclear units, which averages out the zero field splitting. Interactions of the units with the rest of the chain acting as a spin bath give rise to a quantum transition between localized dinuclear states and states of the spin chain. This effect competes with the condensation of the antiferromagnetic dinuclear units into the singlet ground state, producing a characteristic temperature dependence of the shape of the powder EPR spectra. We interpret these features In terms of basic theories of magnetic resonance in coupled spin systems applied to the chain array of dinuclear units. © 2009 American Chemical Society.
author	Perec, Mireille
author_facet	Perec, Mireille
author_sort	Perec, Mireille
title	Magnetism and structure in chains of copper dinuclear paddlewheel units
title_short	Magnetism and structure in chains of copper dinuclear paddlewheel units
title_full	Magnetism and structure in chains of copper dinuclear paddlewheel units
title_fullStr	Magnetism and structure in chains of copper dinuclear paddlewheel units
title_full_unstemmed	Magnetism and structure in chains of copper dinuclear paddlewheel units
title_sort	magnetism and structure in chains of copper dinuclear paddlewheel units
publishDate	2010
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v49_n2_p695_Perec http://hdl.handle.net/20.500.12110/paper_00201669_v49_n2_p695_Perec
work_keys_str_mv	AT perecmireille magnetismandstructureinchainsofcopperdinuclearpaddlewheelunits
_version_	1768546569081061376

Magnetism and structure in chains of copper dinuclear paddlewheel units

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