Trinuclear nickel coordination complexes of phenanthrene-9,10-dione dioxime

A trinuclear nickel complex of phenanthrene-9,10-dione dioxime (H(2)pqd), namely bis­[μ(2)-9,10-bis­(oxido­imino)­phenanthrene]­bis­[μ(2)-10-(oxido­imino)phenanthrene-9-one oxime](phenanthrene-9,10-dione dioxime)trinickel(II) toluene disolvate, [Ni(3)(C(14)H(8)N(2)O(2))(2)(C(14)H(9)N(2)O(2))(2)(C(14)H(10)N(2)O(2))]·2C(7)H(8), has been isolated and its crystal structure determined. This complex features three independent Ni(II) atoms that are arranged in a triangular fashion along with five supporting ligands. There are two square-planar Ni(II) atoms and a third pseudo-octa­hedral Ni(II) atom. While the square-planar Ni(II) atoms are stacked, there are no ligand bridges between them. Each square-planar Ni(II) atom, however, bridges with the pseudo-octa­­hedral Ni(II) atom through Ni—N—O—Ni and Ni—O—Ni bonds. A fluorido­bor­ation reaction of the proton-bridged species gave the analogous complex bis­(μ(2)-bis­{[10-(oxido­imino)-9,10-di­hydro­phenanthren-9-yl­idene]amino}di­fluorido­borato)(phenanthrene-9,10-dione dioxime)trinickel(II) dichloromethane trisolvate, [Ni(3)(C(28)H(16)BF(2)N(4)O(2))(4)(C(14)H(10)N(2)O(2))]·3CH(2)Cl(2), which shows the same binding structure, but features a widened Ni—Ni inter­action between the square-planar Ni(II) atoms. The proton-bridged complex completes the macrocyclic coordination around the square-planar Ni(II) atoms by means of an O—H⋯O hydrogen bond. Both compounds feature O—H⋯N hydrogen bonds between the oxime and the N atoms attached to square-planar nickel atom. The nickel units show no direct inter­action with their nearest neighbors in the extended lattice. Two π-stacking inter­actions between adjacent mol­ecules are found: one with a centroid–centroid distance of 3.886 (2) Å and the other with a centroid–centroid distance of 4.256 (3) Å. In the latter case, although not aromatic, the distance to the centroid of the central phenanthrene ring is shorter, with a distance of 3.528 (3) Å. Toluene mol­ecules occupy the solvent channels that are oriented along the c axis. In the fluorido­boronate structure, the solvent (DCM) was too badly disordered to be modelled, so its contribution was removed using SQUEEZE [Spek (2015 ▸). Acta Cryst. C71, 9–18].