A new family of heterometallic tetranuclear [MnIII2LnIII2] (Ln=Eu, Gd, Tb, Dy) isostructural clusters: Syntheses, crystal structures and magnetic properties

Abstract The initial employment of 2-(2-hydroxy-3-methoxybenzylideneamino)phenol (H 2 L) in Mn–Ln chemistry yields four isostructural Mn III 2 Ln III 2 clusters [Mn III 2 Ln III 2 (O)L 4 (CH 3 OH) 4 (Cl) 2 ]·(Ln = Eu ( 1 ), Gd ( 2 ), Tb ( 3 ) and Dy ( 4 )). All four isostructural clusters were structurally and magnetically characterized. Structural analyses reveal that they are tetranuclear isostructural clusters, each consisting of two dinuclear Mn–Ln entities. Static magnetic studies indicate the presence of dominant ferromagnetic interactions in complexes 3 and 4 , whereas complex 2 , containing Gd, allows quantification of an antiferromagnetic interaction with J Mn–Gd  = −0.41 cm −1 . Dynamic measurements reveal that 3 exhibits slow relaxation of the magnetization and 4 displays single-molecule magnet behavior with an energy barrier of Δ = 15.8 K and a pre-exponential factor of τ 0  = 7.65 × 10 −7  s, while 1 and 2 do not show any out-of-phase ac susceptibility signals. This work highlights the different contributions of the respective lanthanide ions to the overall magnetic behavior in Mn III 2 Ln III 2 systems.