In the crystal structures of the title compounds, namely μ-aqua-κ² O:O-di-μ-diphenylacetato-κ⁴ O:O′-bis[(diphenylacetato-κO)bis(pyridine-κN)nickel(II)], [Ni2(C₁₄H₁₁O₂)₄(C₅H₅N)₄(H₂O)] (1) and μ-aqua-κ² O:O-di-μ-diphenylacetato-κ⁴ O:O′-bis[(2,2′-bipyridine-κ² N,N′)(diphenylacetato-κO)nickel(II)]-acetonitrile-diphenylacetic acid (1/2.5/1), [Ni2(C₁₄H₁₁O₂)4(C₁₀H₈N₂)2(H₂O)]·2.5CH₃CN·C₁₄H₁₂O₂ (2), the complex units are stabilized by a variety of intra-and intermolecular hydrogen bonds, as well as C-H..π and π-π contacts between the aromatic systems of the pyridine, dipyridyl and diphenylacetate ligands. Despite the fact that the diphenylacetate ligand is sterically bulky, this does not interfere with the formation of the described aqua-bridged dimeric core, even with a 2,2′-bipyridine ligand, which has a strong chelating effect.