Heterotrinuclear complexes containing d- and f-block elements: synthesis and structural characterisation of novel lanthanide(III)– nickel(II)–lanthanide(III) compounds bridged by oxamidate

Abstract

The reaction of lanthanide(III) ions with a tripodal ligand HB(pz)₃^– [= hydrotris(pyrazol-1-yl)borate] and a ‘complex ligand’ [NiL]^2– [L = tdo^4– or edo^4–, where H₄tdo = trimethylenebis(oxamide) and H₄edo = ethylenebis(oxamide)] in aqueous solution produced the novel 3d–4f heterotrinuclear complexes [NiL{Ln[HB(pz)₃]₂}₂] [abbreviated as Ni(tdo)Ln₂ (Ln = Eu, Tb or Yb) and Ni(edo)Ln₂ (Ln = Sm to Lu)]. The crystal structures of Ni(tdo)Yb₂ and Ni(edo)Lu₂ have been determined by X-ray diffraction method. The Ni atoms in both have a square-planar environment and the Ln atoms have eight-co-ordinated square-antiprismatic co-ordination geometries.