title: Family of Mn(III)(2)Ln(2)(mu(4)-O) compounds: syntheses, structures, and magnetic properties.
abstract: An isostructural family of tetranuclear aggregates [Mn(III)(2)Ln(2)(O)(Piv)(2)(hep)(4)(NO(3))(4)].MeCN (where Ln = Y(III) (1), Pr(III) (2), Nd(III) (3), Gd(III) (4), Tb(III) (5), Dy(III) (6), Ho(III) (7), and Yb(III) (8)) is reported. They were obtained from the reactions of 2-(2-hydroxyethyl)pyridine (hepH) with a preformed hexanuclear manganese complex, [Mn(6)], and the respective lanthanide salt. The complexes are isomorphous and represent a new heterometallic 3d-4f complex type for this class of ligand. The structural core of 1-8 consists of a distorted Mn(2)Ln(2) tetrahedron with the four metal centers linking through a mu(4)-O(2-) bridging atom. The magnetic properties of all complexes were investigated by variable temperature magnetic susceptibility and magnetization measurements. The magnetic data of all compounds suggest that antiferromagnetic interactions are present between adjacent paramagnetic centers. Complexes 5-7 containing highly anisotropic lanthanide ions (Tb, Dy, and Ho) show slow relaxation of their magnetization.
authors.affiliation: Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstrasse 15, D-76131, Karlsruhe, Germany.
authors.forename: Valeriu
authors.initials: V
authors.lastname: Mereacre
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Lan
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Clérac
authors.forename: Ayuk M
authors.initials: AM
authors.lastname: Ako
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Hewitt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wernsdorfer
authors.forename: Gernot
authors.initials: G
authors.lastname: Buth
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Anson
authors.forename: Annie K
authors.initials: AK
authors.lastname: Powell