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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todo:paper_00201669_v49_n2_p695_Perec2023-10-03T14:17:03Z Magnetism and structure in chains of copper dinuclear paddlewheel units Perec, M. Bagglo, R. Sartoris, R.P. Santana, R.C. Peña, O. Calvo, R. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar 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, M. Bagglo, R. Sartoris, R.P. Santana, R.C. Peña, O. Calvo, R. 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. |
| format |
JOUR |
| author |
Perec, M. Bagglo, R. Sartoris, R.P. Santana, R.C. Peña, O. Calvo, R. |
| author_facet |
Perec, M. Bagglo, R. Sartoris, R.P. Santana, R.C. Peña, O. Calvo, R. |
| author_sort |
Perec, M. |
| 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 |
| url |
http://hdl.handle.net/20.500.12110/paper_00201669_v49_n2_p695_Perec |
| work_keys_str_mv |
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| _version_ |
1807315858933940224 |