Structural and magnetic properties of Ln(III) complexes with diimines and crotonato as a bridging ligand

Five new lanthanide complexes displaying crotonato bridges have been prepared: [Gd2(crot)6(H2O)4] · 4(bpa) (1); [Ho2(crot)7]n · (Hbpa) (2); [Gd2(crot)6(bipy)2] (3); [Ho2(crot)6(bipy)2] (4) and [Nd2(crot)6(H2O)3]n (5), where bipy=2,2′-bipyridine; bpa=di(2-pyridyl)amine; crot=crotonato. The compounds were characterized by magnetic susceptibility measurements and their crystal structures were determined by single crystal X-ray diffraction. These studies showed complexes 1, 3 and 4 to be dimers while structures 2 and 5 are polymeric in nature.