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 SM ISO690:2012ALDOSHIN, Sergei M., SANINA, N., PALII, Andrew, TSUKERBLAT, Boris S.. Theoretical Modeling of the Magnetic Behavior of Thiacalix[4]arene Tetranuclear MnII2GdIII2 and CoII2EuIII2 Complexes. In: Inorganic Chemistry, 2016, vol. 55, pp. 3566-3575. ISSN 0020-1669. DOI: https://doi.org/10.1021/acs.inorgchem.6b00065 |
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  Inorganic Chemistry |
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| Volumul 55 / 2016 / ISSN 0020-1669 | |
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| DOI:https://doi.org/10.1021/acs.inorgchem.6b00065 | |
| Pag. 3566-3575 | |
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In view of a wide perspective of 3d-4f complexes in single-molecule magnetism, here we propose an explanation of the magnetic behavior of the two thiacalix[4]arene tetranuclear heterometallic complexes MnII2GdIII2 and CoII2EuIII2. The energy pattern of the MnII2GdIII2 complex evaluated in the framework of the isotropic exchange model exhibits a rotational band of the low-lying spin excitations within which the Landé intervals are affected by the biquadratic spin-spin interactions. The nonmonotonic temperature dependence of the χT product observed for the MnII2GdIII2 complex is attributed to the competitive influence of the ferromagnetic Mn-Gd and antiferromagnetic Mn-Mn exchange interactions, the latter being stronger (J(Mn, Mn) = -1.6 cm-1, Js(Mn, Gd) = 0.8 cm-1, g = 1.97). The model for the CoII2EuIII2 complex includes uniaxial anisotropy of the seven-coordinate CoII ions and an isotropic exchange interaction in the CoII2 pair, while the EuIII ions are diamagnetic in their ground states. Best-fit analysis of χT versus T showed that the anisotropic contribution (arising from a large zero-field splitting in CoII ions) dominates (weak-exchange limit) in the CoII2EuIII2 complex (D = 20.5 cm-1, J = -0.4 cm-1, gCo = 2.22). This complex is concluded to exhibit an easy plane of magnetization (arising from the CoII pair). It is shown that the low-lying part of the spectrum can be described by a highly anisotropic effective spin-1/2 Hamiltonian that is deduced for the CoII2 pair in the weak-exchange limit. |
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| Cuvinte-cheie Magnetic Relaxation, Dysprosium, complex |
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<?xml version='1.0' encoding='utf-8'?> <oai_dc:dc xmlns:dc='http://purl.org/dc/elements/1.1/' xmlns:oai_dc='http://www.openarchives.org/OAI/2.0/oai_dc/' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xsi:schemaLocation='http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd'> <dc:creator>Aldoshin, S.M.</dc:creator> <dc:creator>Санина, ..</dc:creator> <dc:creator>Палий, ..</dc:creator> <dc:creator>Tsukerblat, B.</dc:creator> <dc:date>2016-04-18</dc:date> <dc:description xml:lang='en'><p>In view of a wide perspective of 3d-4f complexes in single-molecule magnetism, here we propose an explanation of the magnetic behavior of the two thiacalix[4]arene tetranuclear heterometallic complexes Mn<sup>II</sup><sub>2</sub>Gd<sup>III</sup><sub>2</sub> and Co<sup>II</sup><sub>2</sub>Eu<sup>III</sup><sub>2</sub>. The energy pattern of the Mn<sup>II</sup><sub>2</sub>Gd<sup>III</sup><sub>2</sub> complex evaluated in the framework of the isotropic exchange model exhibits a rotational band of the low-lying spin excitations within which the Landé intervals are affected by the biquadratic spin-spin interactions. The nonmonotonic temperature dependence of the χT product observed for the Mn<sup>II</sup><sub>2</sub>Gd<sup>III</sup><sub>2</sub> complex is attributed to the competitive influence of the ferromagnetic Mn-Gd and antiferromagnetic Mn-Mn exchange interactions, the latter being stronger (J(Mn, Mn) = -1.6 cm<sup>-1</sup>, J<sub>s</sub>(Mn, Gd) = 0.8 cm<sup>-1</sup>, g = 1.97). The model for the Co<sup>II</sup><sub>2</sub>Eu<sup>III</sup><sub>2</sub> complex includes uniaxial anisotropy of the seven-coordinate Co<sup>II</sup> ions and an isotropic exchange interaction in the Co<sup>II</sup><sub>2</sub> pair, while the Eu<sup>III</sup> ions are diamagnetic in their ground states. Best-fit analysis of χT versus T showed that the anisotropic contribution (arising from a large zero-field splitting in Co<sup>II</sup> ions) dominates (weak-exchange limit) in the Co<sup>II</sup><sub>2</sub>Eu<sup>III</sup><sub>2</sub> complex (D = 20.5 cm<sup>-1</sup>, J = -0.4 cm<sup>-1</sup>, g<sub>Co</sub> = 2.22). This complex is concluded to exhibit an easy plane of magnetization (arising from the Co<sup>II</sup> pair). It is shown that the low-lying part of the spectrum can be described by a highly anisotropic effective spin-<sup>1</sup>/<sub>2</sub> Hamiltonian that is deduced for the Co<sup>II</sup><sub>2</sub> pair in the weak-exchange limit.</p></dc:description> <dc:identifier>10.1021/acs.inorgchem.6b00065</dc:identifier> <dc:source>Inorganic Chemistry () 3566-3575</dc:source> <dc:subject>Magnetic Relaxation</dc:subject> <dc:subject>Dysprosium</dc:subject> <dc:subject>complex</dc:subject> <dc:title>Theoretical Modeling of the Magnetic Behavior of Thiacalix[4]arene Tetranuclear MnII2GdIII2 and CoII2EuIII2 Complexes</dc:title> <dc:type>info:eu-repo/semantics/article</dc:type> </oai_dc:dc>
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