New 3d-4f heterometallic clusters built from mixed glycine and iminodiacetate acid: Dioctahedron {LaNi} and onion-like {Gd}⊂{Ni} with interesting magnetocaloric effect

The preparation, structures and properties of 3d-4f compounds, undecanuclear [LaNi(Gly)(IDA) (μ-OH)][La(HO) ][Na(HO)(ClO) ](ClO)·5HO (1) and isostructural heptadecanuclear [LnNi(Gly) (IDA)(μ-OH)(H O)](ClO)·11H O (Ln = Gd (2); Nd (3); Sm (4); Tb (5); Dy (6); Y (7)) based on mixed glycine (HGly) and iminodiacetate acid (HIDA) ligands were described. The structure of the [LaNi(μ- OH)(IDA)(Gly)] cationic cluster in 1 can be described as a face-shared and La-centered dioctahedron. However, the [LnNi(Gly)(IDA) (μ-OH)(HO)] cationic clusters in 2-7 bear an onion-like {Ln }⊂{Ni} structure, where the trigonal bipyramid {Ln} core is encapsulated by the outer triangular orthobicupola {Ni} shell. Magnetic studies have been performed for these compounds, and 2 displays dominant ferromagnetic coupling and has a large magnetocaloric effect (21.8 J kg K, ΔH = 7 T). © 2013 The Royal Society of Chemistry.