Synthesis and characterization of [MII(bqb)] (M = Co, Ni, Cu), [N(n-Bu)4][CoIII(bqb)(CN)2], and [N(n-Bu)4][CoIII(bqb)(N3)2] containing deprotonated N,N'-bis(2-quinolinecarboxamide)-1,2-benzene (bqb) – X-ray crystal structures of [NiII(bqb)] and [N(n-Bu)4][CoIII(bqb)(N3)2]

Cobalt(II), nickel(II), copper(II), and two cobalt(III) complexes of a new dianionic ligand, bqb, [H2bqb = N,N'-bis(2-quinolinecarboxamide)-1,2-benzene] have been synthesized and characterized by elemental analyses, IR, and 1H NMR spectroscopy. The crystal and molecular structures of the [Ni(bqb)] (2) and [N(n-Bu)4][CoIII(bqb)(N3)2] (5) complexes were determined by X-ray crystallography. Complex 2 crystallizes in the monoclinic space group C2/c with a distorted square-planar structure including two short Ni–N (1.848 Å) and two long Ni–N (1.958 Å) bonds. The structure consists of sheets formed in the plane parallel to the b axis and diagonal to vectors a and c by intermolecular hydrogen bonds. Complex 5 crystallizes in the monoclinic space group C2 with a distorted octahedral structure. The [N(n-Bu)4]+ ion is disordered at the C3A and C4A atoms of one Bu. The IR and 1H NMR spectra of the complexes are also discussed.Key words: N4-dianionic amido ligand (bqb), (bqb) complexes of Co(II), Ni(II), Cu(II), and Co(III), azide, cyanide, X-ray crystal structures.