A Family of {Ni(2)(II)Ln(2)(III)} Butterfly Complexes: Lanthanide Contraction Effect on the Structures Magnetic Properties

Reactions of lanthanide nitrate, nickel nitrate, and polyhydroxyl Schiff-base ligand 2-(((2-hydroxy-3-methoxyphenyl) methylene) amino)-2-(hydroxymethyl)-1,3-propanediol (H4L) gave rise to a family of butterfly heterotetranuclear 3d-4f clusters formulated as [Ln(2)Ni(2)(H2L)(2)(mu(3)-OCH3)(2)(CH3CN)(2)(NO3)(4)].2CH(3)OH.2H2O [Ln = Pr (1), Sm (2), Eu (3), Tb (4), Er (5)]. Single-crystal X-ray diffraction (XRD) reveals these complexes crystallize in the monoclinic space group P2(1)/c. Both Ln1 and its symmetric Ln1A are coordinated to nine oxygen atoms and consist of two ligands with the same coordination mode mu(3).eta(1):eta(2):eta(1):eta(2):eta(1), two nitrate ions and one mu(3)-OCH3. The five heterotetranuclear Ni(2)(II)Ln(2)(III) complexes display a central planar butterfly topology. The vertices of the body positions of the butterfly are occupied by Ni-II ions in all five complexes, which have been characterized by single-crystal X-ray diffraction, infrared spectroscopy, element analyses, powder X-ray diffraction and thermal gravimetric analyses. The magnetic properties of the complexes have been studied. The results show that complexes 1-3, and 5 exhibit antiferromagnetic exchange between the paramagnetic species, and 4 shows strong ferromagnetic interaction. Graphical Abstract We have shown the successful design and assembly of a new family of tetranuclear, dicationic, heterometallic {Ni-2(II) Ln(2)(III)} complexes characterized by a butterfly-type topology. The results might be promoting the rational design and synthesis of 3d-4f molecule-base magnets materials with fascinating topologies and magnetic behaviours. [GRAPHICS]