Tridecanuclear [MnIII 5 LnIII 8 ] Complexes Derived from N-tButyl-diethanolamine: Synthesis, Structures, and Magnetic Properties

Ayuk M. Ako (1, 2) , Valeriu Mereacre (1) , Rodolphe Clérac (3, 4) , Ian J. Hewitt (1) , Yanhua Lan (1) , Gernot Buth (5) , Christopher E. Anson (1) , Annie K. Powell (1, 2)

1 INSTITUT FüR ANORGANISHE CHEMIE - Institut für Anorganishe Chemie
2 Institute of Nanotechnology, Karlsruhe Institute Postfach
3 CRPP - Centre de recherches Paul Pascal
4 UB - Université Sciences et Technologies - Bordeaux 1
5 Institut für Synchrotronstrahlung

The synthesis, structures and magnetic properties of a family of heterometallic [MnIII 5 LnIII 8 (μ3-OH)12(L2)4(piv)12- (NO3)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-tbutyldiethanolamine (H2L2) with Mn(OAc)2 3 4H2O and Ln(NO3)3 3 6H2O in the presence of pivalic acid (pivH) in MeCN under ambient conditions. Compounds 2-6 are isomorphous and crystallize in the monoclinic space group P21/n with four molecules in the unit cell. The complexes have a centrosymmetric tridecanuclear anionic core consisting of two distorted inner heterometallic [MnIIILnIII 3 (μ3-OH)4]8+ cubane subunits sharing a common Mn vertex flanked by four edge-sharing heterometallic [MnIIILnIII 2 (μ3-OH)4]5+ defect cubane units. Complexes 2-6 are the first high-nuclearity 3d-4f aggregates reported to date using tBu-deaH2 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 MnIII and LnIII ions resulting from the particular angles at the bridging oxygens.

Mots clés: Structures; Magnetic properties; Synthesis

Domaines: Chimie de coordination

Ayuk M. Ako, Valeriu Mereacre, Rodolphe Clérac, Ian J. Hewitt, Yanhua Lan, et al.. Tridecanuclear [MnIII 5 LnIII 8 ] Complexes Derived from N-tButyl-diethanolamine: Synthesis, Structures, and Magnetic Properties. Inorganic Chemistry, 2009, 48 (14), pp. 6713-6723. ⟨10.1021/ic900645d⟩. ⟨hal-00489182⟩