Unusual Conformation of a Dinuclear Paddle Wheel Copper(II) Complex. Synthesis, Structural Characterization and EPR Studies
Author
dc.contributor.author
Paredes García, Verónica
Author
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Santana, Ricardo C.
Author
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Madrid, Rosa
Author
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Vega, Andrés
Author
dc.contributor.author
Spodine Spiridonova, Evgenia
Author
dc.contributor.author
Venegas Yazigi, Diego
Admission date
dc.date.accessioned
2014-01-31T18:51:15Z
Available date
dc.date.available
2014-01-31T18:51:15Z
Publication date
dc.date.issued
2013
Cita de ítem
dc.identifier.citation
Inorg. Chem. 2013, 52, 8369−8377
en_US
Identifier
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doi: 10.1021/ic3027804
Identifier
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https://repositorio.uchile.cl/handle/2250/121814
General note
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Artículos de publicación ISI
en_US
Abstract
dc.description.abstract
An unusual and unique conformation of a paddle wheel
type binuclear copper(II) complex containing acetate and acetamido
ligands, {Cu2(μ2-O2CCH3)4}(OCNH2CH3) (1), was obtained by
solvothermal synthesis. The structural characterization of this compound
shows that the apical (acetamido) ligands are disposed at a 62° dihedral
angle, generating a special conformation as a consequence of the
synthetic method used. This conformation has not been reported in
other paddle wheel copper(II) tetraacetate compounds. Electron
paramagnetic resonance (EPR) spectra of powder samples of (1) were
obtained at 9.5 and 33.8 GHz, while single crystal spectra were obtained
at 33.8 GHz with a B0 applied in three orthogonal planes. The fit of the
single crystal experimental data allowed gave g∥ = 2.345 ± 0.003, and g⊥
= 2.057 ± 0.005. The angular variation of the EPR line allows evaluation
of the fine structure of (1), giving D = −0.337 ± 0.002 cm−1 and E = −0.005 ± 0.001 cm−1. The line width angular dependence,
used together with the Anderson model and Kubo−Tomita theory, permitted the interdimer interaction to be evaluated as |J′| =
(0.051 ± 0.002) cm−1. Using the powder spectral temperature dependence it was possible to evaluate the intradinuclear exchange
coupling constan J0 as −101 ± 2 cm−1, which is considerably lower than that reported for other analogous copper(II) tetraacetate
paddle wheel compounds (CuII−PW), showing the remarkable effect of the conformation of the terminal ligands on the
magnetic interaction.