MA 19.1 Tue 10:45 P2 XPS investigation of a tetranuclear nickel complex— ∙Daniel Taubitz1, Phalguni Chaudhuri2, Vitaly Pavlishchuk2, Karsten Kuepper3, and Manfred Neumann1 — 1Department of Physics, University of Osnabrück, Barbarastrasse 7, D-49069 Osnabrück, Germany — 2Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany — 3Department of Solid State ...

Depending on the Cu(II)/ligand molar ratio, a pyrimidine-based ligand generates a tetranuclear grid (1/1) or a dinuclear stick (2/1). EPR, MS and visible spectroscopy studies suggest that dilution produces partial dissociation of the grid in solution. Replacement of 2-H-pyrimidine by a 2-phenyl-triazine unit prevents the dissociation of the grid. All these factors influence the magnetic propert...

The centrosymmetric tetranuclear title molecule, [Sn4(C3H7O)4Cl4O2], contains two types of Sn atoms, Sn(II) and Sn(IV). The Sn(II) atom has a trigonal-pyramidal coordination environment and is bonded to two O atoms from two iso-propano-late groups and one μ3-oxide atom. The Sn(IV) atom has an octa-hedral coordination environment, formed by two chloride atoms, two μ3-oxide atoms and two O atoms ...

A supramolecular strategy has been applied to construct two tetranuclear lanthanide complexes for investigating the magnetic properties of individual lanthanide ions. The Ln(III) complexes (Ln = Dy, Tb) display field-induced slow magnetization relaxation, typical of single-molecule magnet behavior. The four lanthanide ions in the molecules are well separated by distances of ca. 9 Å, and thus th...

Two M(II) tetranuclear complexes bridged only by azido, Mn4(N3)(7.3)Cl(0.7)L4 (1) and Co4(N3)8L4 (2) in which the four M(II) ions are precisely coplanar bridged only by six azido anions, were obtained by using 4,5-diazafluoren-9-one (L) as a corner ligand. Magnetic studies indicate that ferromagnetic coupling was conducted by the azido anions between M(II) ions. At low temperature, 1 exhibits a...

Vibrational circular dichroism (VCD) spectroscopy was applied to study the stereochemical properties of a star-burst type tetranuclear Ru(III) complex, Δ-(or Λ-)[{Δ-(or Λ-)-Ru(III)(acac)(2)(taet)}(3)Ru(III)] (acac = acetylacetonato; taet = tetraacetylethanato). By comparing the VCD spectra of eight diastereomeric enantiomers, it was shown that the spectra reflected the homo- or hetero-chiral na...

The exploration of the NiX(2)/py(2)CO/Et(3)N (X = F, Cl, Br, I; py(2)CO = di-2-pyridyl ketone; Et(3)N = triethylamine) reaction system led to the tetranuclear [Ni(4)Cl(2){py(2)C(OH)O}(2){py(2)C(OMe)O}(2)(MeOH)(2)]Cl(2)·2Et(2)O (1·2Et(2)O) and [Ni(4)Br(2){py(2)C(OH)O}(2){py(2)C(OMe)O}(2)(MeOH)(2)]Br(2)·2Et(2)O (2·2Et(2)O) and the trinuclear [Ni(3){py(2)C(OMe)O}(4)]I(2)·2.5MeOH (3·2.6MeOH), [Ni(3...

Interest in polynuclear complexes of the 3d metals has been stimulated by the search for new magnetic materials[1, 2] and by demonstration of the occurrence of oligonuclear metal centers in proteins such as urease.[3] Of the relatively small number of reported tetranuclear complexes of S 1 nickel( ) of known structure, the majority have a hemicubaneor TMbutterfly-∫ rather than a squarelike core...

Treatment of (chloro)gold(I) complexes of diand tetra-tertiary phosphines with equivalent quantities of sodium quinoline-2-thiolate in methanol / dichloromethane affords the correspond­ ing (phosphine)gold(I) quinoline-2-thiolates in high yields. The diand tetranuclear complexes, respectively, of a,u>bis(diphenylphosphino)-propane (1), -butane (2) and -pentane (3) and of tris(2-diphenylphosphin...

We report the first structures of simple acetate complexes of vanadium(III) formed in aqueous solution. Paramagnetic (1)H NMR spectroscopy titration experiments indicate the formation of two major V(III)/acetate complexes in acidic aqueous solution for acetate/V(III) < or =4, pD 3.50. A novel tetranuclear cluster and a trinuclear cluster have been characterized by X-ray diffraction studies. Mas...