Structural and Magnetic Studies of New NiII–LnIII Complexes

✍ Scribed by Jean-Pierre Costes; Laure Vendier

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 349 KB
• Volume: 2010
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.201000081

✦ Synopsis

Abstract

The synthesis, structure determination and magnetic studies of dinuclear Ni^II^–Ln^III^ complexes (Ln = Y, La, Pr, Gd) involving ortho‐vanillin as the main ligand are described. Structural studies demonstrate that two types of complexes can be obtained with hexacoordinate Ni ions in slightly deformed octahedral environments and nine‐ or ten‐coordinate lanthanide ions. The Ni and Gd ions are linked by two phenoxo bridges in one complex and two phenoxo bridges and one nitrato bridge in the other. A ferromagnetic interaction operates in the Ni–Gd complex, with a D zero field splitting term for the nickel ion, as in the Ni–La and Ni–Y complexes where these D terms are the only active magnetic terms. Among the factors responsible for the different structures are ionic radii of the Ln ions, solvent and configuration change of the starting nickel complex; the role of solvent seems to be preponderant. The weak value of the ferromagnetic Ni–Gd interaction can be explained by the flexibility and the departure from planarity of the two independent ortho‐vanillin ligands.