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

The initial employment of 2-(2-hydroxy-3-methoxybenzylideneamino)phenol (H2L) in Mn–Ln chemistry yields four isostructural MnIII2LnIII2 clusters [MnIII2LnIII2(O)L4(CH3OH)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 JMn–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 τ0 = 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 MnIII2LnIII2 systems.

Graphical abstractFour MnIII2LnIII2 (Ln = Eu (1), Gd (2), Tb (3) and Dy (4)) clusters demonstrate distinct static and dynamic magnetic properties. Remarkably, 4 exhibits out-of-phase ac signals indicating single-molecule magnet behavior.Figure optionsDownload full-size imageDownload as PowerPoint slide