Synthesis and characterization of new lanthanide complexes with hexadentate hydrazonic ligands

La, Eu, Gd and Tb, nitrate and acetate, complexes of the N2N2′O2 ligand H2L1 are synthesized and characterized; the X-ray crystal structure of the complex [Eu(HL1)(CH3COO)2] · 5H2O is described.The behavior of the analogous N2N2′N2″ ligand H2L2 towards the same ions is investigated, and the X-ray crystal structures of [La(H2L2)(NO3)2(H2O)](NO3), [Eu(H2L2)(NO3)2](NO3) and [Tb(H2L2)(NO3)2](NO3) are reported.