title: Tridecanuclear [Mn(III)5Ln(III)8] complexes derived from N-(t)butyl-diethanolamine: synthesis, structures, and magnetic properties.
abstract: The synthesis, structures and magnetic properties of a family of heterometallic [Mn(III)(5)Ln(III)(8)(mu(3)-OH)(12)(L(2))(4)(piv)(12)(NO(3))(4)(OAc)(4)](-) (Ln = Pr, 2; Nd, 3; Sm, 4; Gd, 5; Tb, 6) aggregates are reported. The complexes were obtained from the direct reaction of N-(t)butyldiethanolamine (H(2)L(2)) with Mn(OAc)(2) x 4 H(2)O and Ln(NO(3))(3) x 6 H(2)O in the presence of pivalic acid (pivH) in MeCN under ambient conditions. Compounds 2-6 are isomorphous and crystallize in the monoclinic space group P2(1)/n with four molecules in the unit cell. The complexes have a centrosymmetric tridecanuclear anionic core consisting of two distorted inner heterometallic [Mn(III)Ln(III)(3)(mu(3)-OH)(4)](8+) cubane subunits sharing a common Mn vertex flanked by four edge-sharing heterometallic [Mn(III)Ln(III)(2)(mu(3)-OH)(4)](5+) defect cubane units. Complexes 2-6 are the first high-nuclearity 3d-4f aggregates reported to date using (t)Bu-deaH(2) as ligand. These compounds show no evidence of slow relaxation behavior above 1.8 K, which appears to be the consequence of the very weak or non-existent magnetic interactions between the Mn(III) and Ln(III) ions resulting from the particular angles at the bridging oxygens.
authors.affiliation: Institut für Anorganische Chemie der Universität Karlsruhe, Engesserstrasse 15, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany.
authors.forename: Ayuk M
authors.initials: AM
authors.lastname: Ako
authors.forename: Valeriu
authors.initials: V
authors.lastname: Mereacre
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Clérac
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Hewitt
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Lan
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