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: [Gd-2(crot)(6)(H2O)(4)]-4(bpa) (1); [Ho-2(crot)(6)](n)(.)(Hbpa) (2), [Gd-2(crot)(6)(bipy)(2)] (3); [Ho-2(crot)(6)(bipy)(2)] (4) and [Nd-2(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. (C) 2003 Elsevier B.V. All rights reserved.