Dimethylsulfoxide-induced trinuclear Co(II) and Ni(II) salamo-type complexes: Syntheses, crystal structures and spectral properties

Two homotrinuclear Co(II) and Ni(II) complexes, [{CoL(OAc)(DMSO)}₂Co]·2DMSO and [{NiL(OAc)(DMSO)}₂Ni] have been synthesized by the reaction of 4,4′-dichloro-2,2′-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol (H₂L) with cobalt(II) and nickel(II) acetate tetrahydrate in the solution of DMSO, respectively, and characterized by elemental analyses, IR, UV–Vis spectra and X-ray crystallography. In the Co(II) complex, terminal Co2 and Co2^#1 atoms located in the N₂O₂ sites, and are both hexa-coordinated with slightly distorted octahedral geometries. While the central Co1 atom is also hexa-coordinated by six oxygen atoms, four are phenoxy oxygen atoms from two (L)²⁻ units, and two oxygen atoms from µ₂-acetate ions, which has formed a octahedral geometry. In the Ni(II) complex, coordination environments of the Ni(II) atoms are similar to those of the Co(II) atoms. Infinite 1D supramolecular structure is formed via abundant intermolecular hydrogen bonding interactions in the Co(II) complex.