New copper'(II), nickel(II), and cobalt(II) complexes are described with the potentially binucleating pyridine N-oxide ligand N,N′-bis(2-N,N′-dimethylaminoethyl)pyridine-2,6-dicarboxamide 1-oxide (medpco). Electronic spectra and X-ray powder diffraction measurements indicate that metal complexes of the type M(medpco)Hal2(H2O)x (Hal = Cl, Br) are five-coordinate. Monomeric structures are proposed with ONN-bonded ligand and coordinated halide. This is analogous to the coordination to one of the coppers in the previously reported X-ray structure of Cu2(medpco)Cl4. Complexes of the type M′2(medpco-2H)Hal2(H2O)x (M′ = Ni,Co), involving deprotonated ligand, are reported. These appear to have N-oxide-bridged structures, involving binucleating ligand, analogous to the previously reported X-ray structure of Cu2(medpco-2H)Cl2. Variable temperature magnetic data for the complexes are discussed.
|Number of pages||12|
|Journal||Journal of Coordination Chemistry|
|Publication status||Published - 01 Dec 2000|