Inorganic Chemistry, Vol.49, No.12, 5460-5471, 2010
Cr-III-Cr-III Interactions in Two Alkoxo-Bridged Heterometallic Zn2Cr2 Complexes Self-Assembled from Zinc Oxide, Reinecke's Salt, and Diethanolamine
Two new tetranuclear complexes, [Zn2Cr2(NCS)(4)(Dea)(2)(HDea)(2)]center dot 4DMSO (1; DMSO = dimethyl sulfoxide) and [Zn2Cr2(NCS)(4)(Dea)(2)(HDea)(2)]center dot 2CH(3)CN (2), were prepared from zinc oxide, Reinecke's salt, NH4[Cr(NCS)(4)(NH3)(2)] center dot H2O, ammonium thiocyanate, and a nonaqueous solution of diethanolamine (H2Dea) in a reaction carried out under open air. Both compounds have similar centrosymmetric crystal structures based on a tetranuclear {Zn2Cr2(mu 3-O)(2)O-4-O)(4)] core. Variable-temperature magnetic susceptibility measurements of 1 and 2 show weak antiferromagnetic coupling between chromium centers. The magnetic data and high-field, high-frequency electron paramagnetic resonance spectra were analyzed in terms of the spin Hamiltonian [GRAPHICS] .