Syntheses, structures, and magnetic properties of manganese-lanthanide hexanuclear complexes

Reactions of manganese acetate and lanthanide acetate with Schiff-base ligands (H(3)beemp = 2,6-bis[((2(2-hydroxyethoxy)ethyl)imino)methyl]-4-methylphenol) yielded hexanuclear clusters of [ Mn(4)(III)Ln(2)(III)(mu(3)-O)(2)(Hbeemp)(2)(OAc)(8)(mu(3)-OMe)(2)(H(2)O)(2)] center dot C(8)H(17)OH (Ln = Gd, Tb, and Y for 1, 2, and 3, respectively). Magnetic susceptibility measurements revealed that the mixed spin systems of 1 and 2 showed ferrimagnetic behavior, while antiferromagnetic interactions were operative among Mn(3+) ions in 3. Ac magnetic susceptibility measurements for 2 showed frequency dependent in-and out-of-phase signals, confirming slow magnetic relaxation of spin reorientations. (c) 2008 Elsevier B.V. All rights reserved.