Mononuclear Lanthanide Single Molecule Magnets Based on the Polyoxometalates [Ln(W5O18)2]9− and [Ln(β2-SiW11O39)
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- 作者：Murad A. AlDamen ; Salvador Cardona-Serra ; Juan M. Clemente-Juan ; Eugenio Coronado ; Alejandro Gaita-Ario ; Carlos Mart-Gastaldo ; Fernando Luis ; Oscar Montero
- 刊名：Inorganic Chemistry
- 出版年：2009
- 出版时间：April 20, 2009
- 年：2009
- 卷：48
- 期：8
- 页码：3467-3479
- 全文大小：507K
- 年卷期：v.48,no.8(April 20, 2009)
- ISSN：1520-510X
文摘
The first two families of polyoxometalate-based single-molecule magnets (SMMs) are reported here. Compounds of the general formula [Ln(W5O18)2]9− (LnIII = Tb, Dy, Ho, and Er) and [Ln(SiW11O39)2]13− (LnIII = Tb, Dy, Ho, Er, Tm, and Yb) have been magnetically characterized with static and dynamic measurements. Slow relaxation of the magnetization, typically associated with SMM-like behavior, was observed for [Ln(W5O18)2]9− (LnIII = Ho and Er) and [Ln(SiW11O39)2]13− (LnIII = Dy, Ho, Er, and Yb). Among them, only the [Er(W5O18)2]9− derivative exhibited such a behavior above 2 K with an energy barrier for the reversal of the magnetization of 55 K. For a deep understanding of the appearance of slow relaxation of the magnetization in these types of mononuclear complexes, the ligand-field parameters and the splitting of the <i>Ji> ground-state multiplet of the lanthanide ions have been also estimated.