Intermolecular iodine-iodine interactions in bis(pyridine-3-carboxylato)[tetrakis(4-iodophenyl)porphyrinato]tin(IV) and bis(pyrimidine-5-carboxylato)[tetrakis(4-iodophenyl)porphyrinato]tin(IV).

Crystals of bis(pyridine-3-carboxylato)[tetrakis(4-iodophenyl)porphyrinato]tin(IV) dimethylformamide sesquisolvate, [Sn(C44H24I4N4)(C6H4NO2)2]·1.5C3H7NO, (I), and bis(pyrimidine-5-carboxylato)[tetrakis(4-iodophenyl)porphyrinato]tin(IV) dimethylformamide sesquisolvate, [Sn(C44H24I4N4)(C5H3N2O2)2]·1.5C3H7NO, (II), exhibit interporphyrin iodine-iodine halogen bonds, which direct the supramolecular assembly of the porphyrin entities into halogen-bonded layers. Each molecule interacts with its four nearest neighbours within the layer via eight I···I interactions at approximately 3.8 and 4.0 Å. The two structures are isomorphous and isometric, with the metalloporphyrin complexes located on centres of crystallographic inversion.