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[mu(2)-9,10-bis(oxidoimino) phenanthrene] bis[mu(2)-10-(oxidoimino)-phenanthrene-9-one oxime](phenanthrene-9,10-dione dioxime) trinickel(II) toluene disolvate, [Ni-3(C14H8N2O2)(2)(C14H9N2O2)(2)(C14H10N2O2)]center dot 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 pseudooctahedral 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 NiO- Ni bonds. A fluoridoboration reaction of the proton-bridged species gave the analogous complex bis(mu(2)-bis{[10-(oxidoimino)-9,10-dihydrophenanthren-9-ylidene]amino} difluoridoborato)(phenanthrene-9,10-dione dioxime) trinickel( II) dichloromethane trisolvate, [Ni-3(C28H16BF2N4O4)(2)(C14H10N2O2)]center dot-3CH(2)Cl(2), which shows the same binding structure, but features a widened NiNi 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 center dot center dot center dot O hydrogen bond. Both compounds feature OH center dot center dot center dot N hydrogen bonds between the oxime and the N atoms attached to squareplanar nickel atom. The nickel units show no direct interaction with their nearest neighbors in the extended lattice. Two similar to -stacking interactions between adjacent molecules are found: one with a centroid-centroid distance of 3.886 (2) angstrom and the other with a centroid-centroid distance of 4.256 (3) angstrom. 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) angstrom. 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].