Synthesis, crystal structures and magnetic studies are reported for four new heterometallic CuIIa??LnIII clusters. The reaction of Cu(NO3)23H2O with triethanolamine (teaH3), pivalic acid, triethylamine and Ln(NO3)36H2O (Ln=Gd, Tb, Dy and Ho) results in the formation of four isostructural nonanuclear complexes of general formula [CuII5LnIII4O2(teaH)4 O2CC(CH3)3 2(NO3)4(OMe)4]2MeOH2Et2O [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 1a??4. Solid-state AC magnetic susceptibility studies show frequency-dependent out-of-phase () signals for 2a??4 below 4a??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 Dya??Cu and Cua??Cu exchange interactions (Dya??Dy zero), some ferro- and some antiferromagnetic in character, that explain its magnetic behaviour.
Langley, S., Ungur, L., Chilton, N., Moubaraki, B., Chibotaru, L., & Murray, K. (2011). Structure, magnetism and theory of a family of nonanuclear CuII5LnIII4-triethanolamine clusters displaying single-molecule magnet behaviour. Chemistry - A European Journal, 17(33), 9209 - 9218. https://doi.org/10.1002/chem.201100218