Clathrate solvates of tetrakis(4-methoxycarbonylphenyl)porphyrin and its zinc(II)-pyridine complex, in which the porphyrin host structures are stabilized by porphyrin-porphyrin stacking and C-H⋯O attractions

Tetrakis(4-methoxycarbonylphenyl)porphyrin, or tetramethyl 4,4′,4″,4‴-porphyrin-5,10,15,20-tetrabenzoate, crystallizes as a nitrobenzene 1.9-solvate, C₅₂H₃₈N₄O ₈·1.9C₆H₅NO₂, (I). The solvent molecules are contained in extended channels which propagate through the host lattice between parallel screw/ glide-related columns of offset-stacked porphyrin entities. Side packing of these columns involves π-π interactions between the methoxycarbonylphenyl residues. Molecules of the porphyrin host lie on crystallographic inversion centres. The zinc(II)-pyridine derivative pyridine(tetramethyl 4,4′,4″,4‴-porphyrin-5,10,15, 20-tetrabenzoato)zinc(II), [Zn(C₅₂H₃₆N₄O ₈)(C₅H₅N)], (II), is a square-pyramidal five-coordinate complex with pyridine as an apical ligand, which crystallizes as a chloroform-pyridine solvate. The metalloporphyrin-pyridine units form an open layered arrangement, occluding the non-coordinated solvent moieties within the intralayer interporphyrin voids. Within such arrays, the host porphyrin molecules are in contact with one another through the peripheral methoxycarbonyl substituents. The crystal packing consists of a bilayered arrangement of inversion-related porphyrin layers, with the axial ligands mutually penetrating into the voids of neighbouring arrays and tight offset stacking of these bilayers.