Crystal structure of an unknown solvate of (piperazine-κN){5,10,15,20-tetrakis[4-(benzoyloxy)phenyl]porphyrinato-κ4N}zinc

Abstract

The title compound, [Zn(C72H44N4O8)(C4H10N2)] or [Zn(TPBP)(pipz] (where TPBP and pipz are 5,10,15,20-tetrakis[4-(benzoyloxy)phenyl]porphyrinato and piperazine ligands respectively), features a distorted square-pyramidal coordination geometry about the central ZnII atom. This central atom is chelated by the four N atoms of the porphyrinate anion and further coordinated by a nitrogen atom of the piperazine axial ligand, which adopts a chair confirmation. The average Zn—N(pyrrole) bond length is 2.078 (7) Å and the Zn— N(pipz) bond length is 2.1274 (19) Å. The zinc cation is displaced by 0.4365 (4) Å from the N4C20 mean plane of the porphyrinate anion toward the piperazine axial ligand. This porphyrinate macrocycle exhibits major saddle and moderate ruffling deformations. In the crystal, the supramolecular structure is made by parallel pairs of layers along (100), with an interlayer distance of 4.100 Å while the distance between two pairs of layers is 4.047 Å. A region of electron density was treated with the SQUEEZE [Spek (2015). Acta Cryst. C71, 9–18] procedure in PLATON following unsuccessful attempts to model it as being part of disordered n-hexane solvent and water molecules. The given chemical formula and other crystal data do not take into account these solvent molecules.

Keywords

• crystal structure
• zinc porphyrin
• piperazine
• hydrogen bonds
• UV–visible spectra