Intramolecular C-H•••π interactions in metal-porphyrin complexes

Cambridge Structural Database (CSD) was screened in order to find intramolecular C-H...pi interactions with a chelate ring of coordinated porphyrin. It was found 154 crystal structures with 244 intramolecular C-H...pi interactions in transition metal complexes with derivatives of porphyrin. Comparison of interacting distances indicates that interactions of hydrogen atoms in positions 2 and 6 of axially coordinated pyridine are more favorable with ruffled than with planar porphyrin.