In the title complex, trans-{2,2′-[cyclo­hexane-1,2-diyl­bis­(ni­t­rilo­methyl­idyne)]­di­phenol­ato-κ⁴O,N,N′,O′}­nickel(II)–chloro­form (1/1), [Ni(C₂₀H₂₀N₂O₂)]·CHCl₃, the Ni atom has a square-planar geometry, slightly tetrahedrally distorted. The Ni—N and Ni—O bonding distances are within the expected ranges for Ni–Schiff base derivatives. The di­imine bridge has a gauche conformation with the cyclo­hexyl ring almost coplanar with the NiN₂O₂ plane. The complex mol­ecules pack in dimers with an NiNi distance of 3.59 (1) Å and form a three-dimensional structure displaying a herring-bone configuration. Channels are occupied by solvent mol­ecules, which are involved in C—HO hydrogen bonds with the ligand O atoms.

In the title compound, [Ni(C₁₉H₂₀N₂O₄)(H₂O)₂], the Ni atom has a distorted octahedral coordination geometry in which the tetradentate Schiff base ligand acts as a cis-N₂O₂ donor defining an equatorial plane, and water mol­ecules occupy the axial positions. The two parts of the mol­ecule are related by a mirror plane that passes through the Ni atom and is perpendicular to the equatorial plane. The angular distortions from normal octahedral geometry are in the range 1-6°, and the equatorial plane, defined by the donor atoms of the Schiff base, is almost square planar. The six-membered ring comprising the Ni, the imine N and the propyl­ene C atoms adopts a half-chair conformation. The Ni-O [2.017 (2) Å] and Ni-N [2.071 (2) Å] distances are within the ranges expected for high-spin octahedral nickel complexes.