N,N′-bis(5-bromo-2-hydroxy-3-methoxybenzylidene)-1,3-diaminopropane Cu-4f-Cu and Cu-4f complexes: Synthesis, crystal structures and magnetic properties

Synthesis, crystal structures and magnetic studies of new heterotri- and heterodinuclear complexes having general formulae [Cu(2)Ln(L)(2)(NO3)(H2O)(2)](NO3)(2)center dot 3H(2)O (where Ln = Ce (1), Pr (2), Nd (3) and La (4)), and [CuLn(L)(NO3)(2)(H2O)(3)MeOH]NO3 center dot MeOH (where Ln = Dy (5) and Er (6)), respectively involving the Schiff base (H2L) as main ligand are reported. The heterotrinuclear complexes crystallize in the monoclinic space group C2/c with the molecule lying on the twofold axis (Z' = 0.5), while the dinuclear complexes (5 and 6) form monoclinic crystals with space group P2(1)/n. The lanthanide(III) cation in Cu-II-Le(III)-Cu-II core is 10-coordinated, whereas in dinuclear compounds the coordination number for Ln(III) ion is only nine. The polyhedra formed around terminal Cu(II) ions in 1-3 have a shape of deformed tetragonal pyramid with water molecule in apical position. In crystals 5 and 6 the Cu(II) has octahedral coordination. The temperature dependence of the magnetic susceptibility and the field-dependent magnetization indicated that the interaction between Cu-II and Ln(II) ions is antiferromagnetic for Ln = Ce, Pr and Nd and ferromagnetic for Ln = Dy and Er. (C) 2011 Elsevier Ltd. All rights reserved.