Publication Date

2018

Department

Ames Laboratory; Materials Science and Engineering

Campus Units

Materials Science and Engineering, Ames Laboratory

Report Number

IS-J 9582

DOI

10.1039/C8TC00322J

Journal Title

Journal of Materials Chemistry C

Volume Number

6

First Page

2862

Last Page

2872

Abstract

A family of isostructural undecanuclear 3d–4f coordination clusters of formula [FeIII7LnIII4O4(OH)3(tea)2(Htea)3(Piv)7(H2O)2(NO3)3], where Ln = Y (1), Gd (2), Tb (3), Dy (4); PivH ≡ pivalic acid and H3tea ≡ triethanolamine, was synthesised. The central Fe7 core of the coordination cluster can be described in terms of two {Fe4O2} butterfly motifs sharing a common body Fe atom. The two Fe4 mean-planes subtend a dihedral angle of ca. 72°. The Tb (3) and Dy (4) compounds show Single Molecule Magnet (SMM) behaviour as confirmed by ac-susceptibility and μ-SQUID measurements. Furthermore, 57Fe Mössbauer spectra of 1–4 confirm the presence of high-spin FeIII sites. The spectra of all complexes in the high temperature range (30–300 K) show broad overlapping doublets which were assigned to the body and wing-tip pairs of metal ions within the Fe7 core. The low temperature Mössbauer spectra show dependence on the nature of the rare-earth metal as a result of its interaction with the iron sites. Thus, we observed a transition from fast (2), to intermediate (1) and very slow (frozen) (3, 4) spin fluctuation phenomena in these compounds.

Language

en

Department of Energy Subject Categories

29 ENERGY PLANNING, POLICY, AND ECONOMY

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Available for download on Friday, March 01, 2019

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