Structural, MALDI-TOF-MS, magnetic and spectroscopic studies of new dinuclear copper(II), cobalt(II) and zinc(II) complexes containing a biomimicking μ-OH bridge.
The Py(2)N(4)S(2) octadentate coordinating ligand afforded dinuclear cobalt, copper and zinc complexes and the corresponding mixed metal compounds. The overall geometry and bonding modes have been deduced on the basis of elemental analysis data, MALDI-TOF-MS, IR, UV-vis and EPR spectroscopies, single-crystal X-Ray diffraction, conductivity and magnetic susceptibility measurements. In the copper and zinc complexes, a μ-hydroxo bridge links the two metal ions. In both cases, the coordination geometry is distorted octahedral. Magnetic and EPR data reveal weakly antiferromagnetic high spin Co(II) ions, compatible with a dinuclear structure. The magnetic characterization of the dinuclear Cu(II) compound indicates a ferromagnetically coupled dimer with weak antiferromagnetic intermolecular interactions. The intra-dimer ferromagnetic behaviour was unexpected for a Cu(II) dimer with such μ-hydroxo bridging topology. We discuss the influence on the magnetic properties of non-covalent interactions between the bridging moiety and the lattice free water molecules.
Departamento de Química Inorgánica, Facultade de Química, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, España.
Cristina
C
Núñez
Rufina
R
Bastida
Alejandro
A
Macías
Laura
L
Valencia
Nicolás I
NI
Neuman
Alberto C
AC
Rizzi
Carlos D
CD
Brondino
Pablo J
PJ
González
José Luis
JL
Capelo
Carlos
C
Lodeiro
D003035:Cobalt / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D004578:Electron Spin Resonance Spectroscopy; D008280:Magnetics; D008968:Molecular Conformation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet; D015032:Zinc / Q000737:chemistry*
D056831:Coordination Complexes; D003035:Cobalt; D003300:Copper; D015032:Zinc