Synthesis, structure and magnetic properties of unsymmetrical dodecanuclear Mn–Ln clusters
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- 作者：Valeriu Mereacre ; Denis Prodius ; Ayuk M. Ako ; Narpinder Kaur ; Janusz Lipkowski ; Charles Simmons ; Naresh Dalal ; Ion Geru ; Christopher E. Anson ; Annie K. Powell ; Constantin Turta
- 关键词：Lanthanide– ; manganese compounds ; Benzoic acid ; Magnetic properties
- 刊名：Polyhedron
- 出版年：2008
- 出版时间：4 August 2008
- 年：2008
- 卷：27
- 期：11
- 页码：2459-2463
- 全文大小：660 K
文摘
Reaction of manganese acetate and lanthanide nitrates in the presence of excess of PhCOOH affords highly asymmetric dodecanuclear mixed-metal [Mn10Ln2(OH)(O)8(PhCOOH)(PhCOO)19] (Ln = PrIII (1), NdIII (2)) clusters. The similar reaction, but with only 2 equiv. of PhCOOH resulted in the compounds with higher nuclearity [Mn11Eu4(O)8(OH)8(PhCOO)18(NO3)2(H2O)6]NO3 · 4CH3CN (3). Variable-temperature solid-state magnetic susceptibility of 1 and 2 in the temperature range 1.8–300 K were carried out, and for both complexes antiferromagnetic exchange interactions between the metal centers were observed, giving an estimated S = 17/2 ground state. AC magnetic susceptibility data have revealed out-of-phase signals, which suggest that these complexes exhibit a slow relaxation of magnetization as observed in single-molecule magnets.