A tetranuclear holmium compound exhibiting single molecule magnet behavior

Abstract The synthesis, structure, and magnetic properties of a new tetranuclear holmium cluster [Ho III 4 ( μ 3 -OH) 2 (L) 4 (piv) 2 (DMF) 2 ]·2DMF ( 1 ) is reported, where the Schiff base H 2 L ligand is 2-hydroxy-3-methoxy-phenylsalicylaldimine and piv is pivalate. The cluster has a planar “butterfly” Ho 4 core, which is bridged by two μ 3 -hydroxide and six phenoxide oxygen atoms. Magnetically, compound 1 displays field-induced slow relaxation of magnetization. Fitting the dynamic magnetic data to the Arrhenius law gives energy barrier ΔE/k B  = 21.49 K and τ 0  = 6.97 × 10 − 7  s.