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Magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets

The structures and magnetic properties of the arsenic- and selenium-ligated dysprosium single-molecule magnets (SMMs) [Cp′(3)Dy(AsH(2)Mes)] (3-Dy), [(η(5)-Cp′(2)Dy){μ-As(H)Mes}](3) (4-Dy), [Li(thf)(4)](2)[(η(5)-Cp′(2)Dy)(3)(μ(3)-AsMes)(3)Li] ([Li(thf)(4)](2)[5-Dy]), and [(η(5)-Cp′(2)Dy){μ-SeMes}](3)...

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Autores principales: Pugh, Thomas, Vieru, Veacheslav, Chibotaru, Liviu F., Layfield, Richard A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Royal Society of Chemistry 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5968533/
https://www.ncbi.nlm.nih.gov/pubmed/29899940
http://dx.doi.org/10.1039/c5sc03755g
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author Pugh, Thomas
Vieru, Veacheslav
Chibotaru, Liviu F.
Layfield, Richard A.
author_facet Pugh, Thomas
Vieru, Veacheslav
Chibotaru, Liviu F.
Layfield, Richard A.
author_sort Pugh, Thomas
collection PubMed
description The structures and magnetic properties of the arsenic- and selenium-ligated dysprosium single-molecule magnets (SMMs) [Cp′(3)Dy(AsH(2)Mes)] (3-Dy), [(η(5)-Cp′(2)Dy){μ-As(H)Mes}](3) (4-Dy), [Li(thf)(4)](2)[(η(5)-Cp′(2)Dy)(3)(μ(3)-AsMes)(3)Li] ([Li(thf)(4)](2)[5-Dy]), and [(η(5)-Cp′(2)Dy){μ-SeMes}](3) (6-Dy) are described. The arsenic-ligated complexes 4-Dy and 5-Dy are the first SMMs to feature ligands with metalloid elements as the donor atoms. The arsenide-ligated complex 4-Dy and the selenolate-ligated complex 6-Dy show large anisotropy barriers in the region of 250 cm(–1) in zero d.c. field, increasing to 300 cm(–1) upon 5% magnetic dilution. Theoretical studies reveal that thermal relaxation in these SMMs occurs via the second-excited Kramers' doublet. In contrast, the arsinidene-ligated SMM 5-Dy gives a much smaller barrier of 23 cm(–1), increasing to 35 cm(–1) upon dilution. The field-dependence of the magnetization for 4-Dy and 5-Dy at 1.8 K show unusual plateaus around 10 kOe, which is due to the dominance of arsenic-mediated exchange over the dipolar exchange. The effects of the exchange interactions are more pronounced in 5-Dy, which is a consequence of a small but significant increase in the covalent contribution to the predominantly ionic dysprosium-arsenic bonds. Whereas the magnetically non-dilute dysprosium SMMs show only very narrow magnetization versus field hysteresis loops at 1.8 K, the impact of magnetic dilution is dramatic, with butterfly-shaped loops being observed up to 5.4 K in the case of 4-Dy. Our findings suggest that ligands with heavier p-block element donor atoms have considerable potential to be developed more widely for applications in molecular magnetism.
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spelling pubmed-59685332018-06-13 Magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets Pugh, Thomas Vieru, Veacheslav Chibotaru, Liviu F. Layfield, Richard A. Chem Sci Chemistry The structures and magnetic properties of the arsenic- and selenium-ligated dysprosium single-molecule magnets (SMMs) [Cp′(3)Dy(AsH(2)Mes)] (3-Dy), [(η(5)-Cp′(2)Dy){μ-As(H)Mes}](3) (4-Dy), [Li(thf)(4)](2)[(η(5)-Cp′(2)Dy)(3)(μ(3)-AsMes)(3)Li] ([Li(thf)(4)](2)[5-Dy]), and [(η(5)-Cp′(2)Dy){μ-SeMes}](3) (6-Dy) are described. The arsenic-ligated complexes 4-Dy and 5-Dy are the first SMMs to feature ligands with metalloid elements as the donor atoms. The arsenide-ligated complex 4-Dy and the selenolate-ligated complex 6-Dy show large anisotropy barriers in the region of 250 cm(–1) in zero d.c. field, increasing to 300 cm(–1) upon 5% magnetic dilution. Theoretical studies reveal that thermal relaxation in these SMMs occurs via the second-excited Kramers' doublet. In contrast, the arsinidene-ligated SMM 5-Dy gives a much smaller barrier of 23 cm(–1), increasing to 35 cm(–1) upon dilution. The field-dependence of the magnetization for 4-Dy and 5-Dy at 1.8 K show unusual plateaus around 10 kOe, which is due to the dominance of arsenic-mediated exchange over the dipolar exchange. The effects of the exchange interactions are more pronounced in 5-Dy, which is a consequence of a small but significant increase in the covalent contribution to the predominantly ionic dysprosium-arsenic bonds. Whereas the magnetically non-dilute dysprosium SMMs show only very narrow magnetization versus field hysteresis loops at 1.8 K, the impact of magnetic dilution is dramatic, with butterfly-shaped loops being observed up to 5.4 K in the case of 4-Dy. Our findings suggest that ligands with heavier p-block element donor atoms have considerable potential to be developed more widely for applications in molecular magnetism. Royal Society of Chemistry 2016-03-01 2015-12-15 /pmc/articles/PMC5968533/ /pubmed/29899940 http://dx.doi.org/10.1039/c5sc03755g Text en This journal is © The Royal Society of Chemistry 2016 http://creativecommons.org/licenses/by/3.0/ This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0)
spellingShingle Chemistry
Pugh, Thomas
Vieru, Veacheslav
Chibotaru, Liviu F.
Layfield, Richard A.
Magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets
title Magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets
title_full Magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets
title_fullStr Magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets
title_full_unstemmed Magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets
title_short Magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets
title_sort magneto-structural correlations in arsenic- and selenium-ligated dysprosium single-molecule magnets
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5968533/
https://www.ncbi.nlm.nih.gov/pubmed/29899940
http://dx.doi.org/10.1039/c5sc03755g
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