Stacking diagrams showing the π - π interactions: a) in [Fe(TPP)(2-MeHIm)]·(l,10-phen) (Form A), all atoms are contoured at the 10% probability level for clarity; b) in [Fe(OEP)(2-MeHIm)]·(l,10-phen), all atoms are contoured at the 50% probability level; c) in [Fe(TPP)(2-MeHIm)]·(l,10-phen) (Form B), all atoms are contoured at the 50% probability level.