Homodinuclear {Ln III 2 } (Ln III = Gd III , Tb III , Ho III , and Dy III ) Complexes: Field‐Induced SMM Behavior of the Dy III and Tb III Analogues

A family of four dinuclear complexes, [NHEt 3 ] 2 [Ln 2 ( µ ‐NO 3 ) 2 (NO 3 ) 2 (HL) 2 ] [Ln = Gd III ( 1 ), Tb III ( 2 ), Ho III ( 3 ), Dy III ( 4 )], were synthesized by the reaction of an enolizable multidentate Schiff base ligand H 3 L (H 3 L = N′ ‐(2‐hydroxy‐3‐methoxy‐5‐nitrobenzylidene)‐2‐(hydroxyimino)propanehydrazide) with hydrated lanthanide nitrates in the presence of NEt 3 . The molecular structure of complexes 1 – 4 was confirmed by single‐crystal XRD analysis. All of the centrosymmetric complexes are dianionic, isostructural and each of the Ln III centers is nine‐coordinate and adopts a muffin like coordination geometry as indicated by SHAPE analysis. The dynamic magnetization studies revealed that the compounds 2 and 4 are field‐induced single‐molecule magnets with effective energy barriers, U eff = 34(2) K (for 2 ) and 80(3) K (for 4 ) and pre‐exponential factors, τ o = 1.1 × 10 –8  s (for 2 ) and 1.15 × 10 –7  s (for 4 ).