The molecule of the title complex, [Ni2(C21H15N3O5)2(H2O)4]·4C3H7NO, is located on an inversion centre. This results in a dimeric Ni(II) complex, with the two Ni(II) atoms bridged by phenolate O atoms. The tridentate ligand is chelated to each Ni(II) atom via one N and two O atoms of the imino-late form of the hydrazide moiety, which has the same conformation as the free ligand. The coordination geometry around each Ni(II) ion is slightly distorted octa-hedral. A supra-molecular three-dimensional architecture is created by dominant inter-molecular O-H⋯N, O-H⋯O and C-H⋯O hydrogen-bonding inter-actions. These are augmented by two C-H⋯π inter-actions and a π-π inter-action with a centroid-centroid distance of 3.681 (2) Å.
* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.