The interaction of isonicotinamide and nicotinamide (Inia and Nia, respectively) with complex compounds [CoN3(DH)2L], where DH = monodeprotonated dimethylglyoxime, L = derivative of pyridine-containing sulfanilamide resulted in new complexes [CoN3(DH)2(Inia)] (1) and [CoN3(DH)2(Nia)] (2), whose crystal structures have been determined by single crystal X-ray analysis. Compounds 1 and 2 crystallize in the form of dark-red plates in the monoclinic space groups P21/c and P21/n, respectively. Crystals of 1 and 2 are readily soluble in DMSO and DMF. The results of X ray study showed that the asymmetric part of the unit cell contains one complex in 1, and two crystallographically independent and identical in composition complexes (A and B) in 2 (Fig. 1).Fig. 1. Structure of the molecular complexes 1 and 2 The compounds have molecular structures. The usual octahedral coordination environment of the metal is realized in both of them. Two DH‾ residues coordinated in chelate mode display in the equatorial plane of the complexes, while the organic ligands Inia or Nia and inorganic anion N3 - are situated in the apical positions, coordinated via nitrogen atoms. Two DH‾ residues are united by O– H...O hydrogen bonds (Fig. 1) with the formation of stable [Co(DH)2] fragment typical for Co(III) dioximates. Distances Co–N(DH) in 1 and 2 are in the interval of 1.885(3) – 1.907(4) Å, Co–N(Inia, Nia) : 1.972(3) – 1.975(3) Å, and Co–N(N3) : 1.960(4) – 2.008(3) Å, all being consistent with those in the similar Co(III) complexes with the dioximes [1].Fig. 2. The mode of self-association through N–H⋅⋅⋅О H-bond in 1 and 2 In crystals 1 and 2 the molecular complexes are combined by intermolecular hydrogen bonds of N– H...O and N–H⋅⋅⋅N types in which the NH2-groups of the Inia or Nia ligands act as proton donors. The self-association in 1 occurs via two centrosymmetric N–H...O hydrogen bonds with the formation of supramolecular synthon R2 2(8), while in 2 one such H-bond links two crystallographically independent complexes A and B (Fig. 2). [1] M. N. Ponnuswamy, J. Trotter Acta Crystallogr. 39С (1983) 726.