Abstract: Coordination compounds of various nickel(II) carboxylates (valerate, benzoate, phthalate, maleate, fumarate) with salicyl hydrazide have been synthesized and studied by IR spectroscopy. The crystal structure of the complex of nickel(II) phthalate with salicyl hydrazide [NiL3]Pht (L is salicyl hydrazide, Pht2– is phthalic acid dianion) has been determined by X-ray diffraction. The structural units of the crystal are complex cations [NiL3]2+ and phthalic acid anions Pht2– joined together by cation–anion N–H…O, O–H…O hydrogen bonds. The nickel atom has distorted octahedron coordination formed by three oxygen and three nitrogen atoms of the three bidentate-chelate ligands L (Ni–O 2.027–2.059, Ni–N 2.067–2.097 Å). © 2021, Pleiades Publishing, Ltd.