Synthesis, crystal structures and magnetic characterization of heterodinuclear CuIIGdIII and CuIITbIII Schiff base complexes

Preparation, crystal structures and magnetic properties of new heterodinuclear (CuGdIII)-Gd-II (1) and (CuTbIII)-Tb-II (2) complexes [CuLn(L)(NO3)(2)(H2O)(3)MeOH]NO3 center dot MeOH (where Ln = Gd, Tb) with the hexadentate Schiff-base compartmental ligand N,N'-bis(5-bromo-3-methoxysalicylidene)propylene-1,3-diamine (H2L = C19H20N2O4Br2) (0) have been described. Crystal structure analysis of 1 and 2 revealed that they are isostructural and form discrete dinuclear units with dihedral angle between the O1Cu1O2 and O1Gd1/Tb1O2 planes equal to 2.5(1)degrees and 2.6(1)degrees, respectively. The variable-temperature and variable-field magnetic measurements indicate that the metal centers in 1 and 2 are ferromagnetically coupled (J = 7.89 cm(-1) for 1). Crystal and molecular structure of the Schiff base ligand (0) has been also reported. The complex formation changes the conformation of Schiff base ligand molecule. (C) 2011 Elsevier B.V. All rights reserved.