Two heterometallic {Co^II₆Ln^III₂} (Ln = Dy, Ho) clusters with local symmetry exhibiting single‐molecule magnet behaviours

Abstract

Two novel 3d‐4f clusters with {CoII6LnIII2} (Ln = Dy (1), Ho (2)) cores are fabricated, with formulas of {[Co6Ln2(O)2(dhpb)6(NO3)2(DMF)2]·H2O} (H2dhpb = 6,6′‐dihydroxyl‐2,2′‐bipyridine, DMF = dimethyl formamide), which consist of two asymmetrical [Co3Ln] pyrimids bridged by a μ4‐O bridge. The {CoII6LnIII2} core exhibits a bicapped anti‐trigonal‐prism configuration, and is held together by six dhpb2− ligands. Interestingly, the LnIII ions are seven‐coordinate in pseudo‐D5h symmetry. The magnetic studies indicate that both compounds 1 and 2 show significant single‐molecule magnet (SMM) behaviours.