Abstract
The two trinuclear nickel(II) complexes, Ni~3~(C~13~H~15~N~2~O~3~)~2~(C~5~H~5~N)~4~ (1) and Ni~3~(C~13~H~15~N~2~O~3~)~2~(C~5~H~5~N)~2~‐ (C~3~H~7~NO)~2~ (2), were prepared by the reaction of Ni(OAc)~2~·4H~2~O with N‐hexanoylsalicylhydrazide. The crystal structures of complexes were determined by X‐ray diffraction analysis. Complex 1 takes triclinic symmetry with space group P‐1 and cell dimensions of a=0.92377(2) nm, b=1.08786(6) nm, c=1.29391(3) nm, α=76.395(4) °, β=78.418(3)°, γ=67.378(4)°, V=1.15772(7) nm^3^, Z=1, µ=12.63 cm^−1^. Complex 2 belongs to triclinic system and __P__2(1) space group and the crystallographic data: a=1.4889(2) nm, b=1.0389(1) nm, c=1.4994(2) nm, β=96.174(4)°, V=2.3058(5) nm^3^, Z=2, µ=12.70 cm^−1^. The structures of the two molecules are similar. The three nickel atoms in each molecule of the two title complexes arrange in a strictly linear structure. The central nickel atom of the molecule adopts octahedral configuration, while the two nickel atoms on the two sides adopt square‐planar configuration in each molecule. But the central nickel atoms of the two complexes have different axial ligands, which cause a slight difference in the bond distances of the octahedron. The antibacterial activity of compound 1 against seven common bacteria was investigated.