New dinuclear nickel(II) and iron(II) complexes with a macrocyclic ligand containing a N6S2 donor-set: Synthesis, structural, MALDI-TOF-MS, magnetic and spectroscopic studies

作者：Nunez Cristina; Bastida Rufina^*; Macias Alejandro; Valencia Laura; Ribas Joan; Luis Capelo Jose; Lodeiro Carlos

来源：Dalton Transactions, 2010, 39(33): 7673-7683.

DOI：10.1039/c0dt00182a

A series of dinuclear Ni(II) and Fe(II) complexes with a Py2N4S2 coordinating octadentate macrocyclic ligand L prepared by direct reactions have been studied. The overall geometry and bonding mode have been deduced on the basis of elemental analysis data, infrared, MALDI-TOF-MS, UV-vis spectroscopy, X-ray diffraction, conductivity and magnetic susceptibility measurements. In general both M2+ centres are sited into the macrocyclic cavity coordinated to a pyridinic nitrogen atom, one sulfur atom, two secondary amine groups from the macrocyclic backbone and completing the coordination spheres with two solvent or anionic molecules in a distorted octahedral geometry, except in the case of [Ni2L(mu-Cl)(H2O)(2)](BF4)(3)center dot 2H(2)O, where the metal ions are sited in the macrocyclic cavity coordinated to a pyridinic nitrogen atom, one sulfur atom, two secondary amine groups from the macrocyclic backbone, one water molecule and one chloride ion acting as a bridge between the two centres in a distorted octahedral geometry. The magnetic properties of the nickel(II) complexes, [Ni2L(CH3CN)(4)](BF4)(4)center dot 3.5CH(3)CN (11) and [Ni2L(mu-Cl)(H2O)(2)](BF4)(3)center dot 2H(2)O (12) has been recorded in the solid state and indicates an unexpected ferromagnetic exchange in both cases, especially in compound 11 because no similar systems are previously reported in the literature presenting this magnetic behaviour. Further complexes with similar ligands are in progress to corroborate this unexpected ferromagnetic behaviour.

• 出版日期2010