Structure, Magnetism and Theory of a Family of Nonanuclear CuII5LnIII4–Triethanolamine Clusters Displaying Single-Molecule Magnet Behaviour

Synthesis, crystal structures and magnetic studies are reported for four new heterometallic CuII–LnIII clusters. The reaction of Cu(NO3)2·3H2O with triethanolamine (teaH3), pivalic acid, triethylamine and Ln(NO3)3·6H2O (Ln=Gd, Tb, Dy and Ho) results in the formation of four isostructural nonanuclear complexes of general formula [CuII5LnIII 4O2(teaH)4{O2CC(CH3)3}2-(NO3)4(OMe)4]·2MeOH·2Et2O [Ln=Gd (1), Tb (2), Dy (3) and Ho (4)]. The metal core of each cluster is made up of four face- and vertex-sharing tetrahedral units. Solid-state DC magnetic susceptibility studies reveal competing anti- and ferromagnetic interactions within each cluster leading to large-spin ground states for 1–4. Solid-state AC magnetic susceptibility studies show frequency-dependent out of-phase (c00M) signals for 2–4 below 4 K, suggestive of single-molecule magnet behaviour. Ab initio calculations on one of the anisotropic examples (3) provided a rare set of J values for Dy–Cu and Cu–Cu exchange interactions (Dy–Dy zero), some ferro- and some antiferromagnetic in character, that explain its magnetic behaviour.

Publication year:2011

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BOF-publication weight:2

CSS-citation score:2

Authors:International

Authors from:Higher Education

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