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

Preparation, crystal structures and magnetic properties of new heterodinuclear CuIIGdIII (1) and CuIITbIII (2) complexes [CuLn(L)(NO3)2(H2O)3MeOH]NO3·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)° and 2.6(1)°, 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.