title: Stacked double-macrocyclic ligands. 1. synthesis of a 'crowned' porphyrin.
mesh_terms: D001665:Binding Sites; D055598:Chemical Phenomena; D002621:Chemistry; D008024:Ligands / Q000138:chemical synthesis; D008665:Metalloporphyrins / Q000138:chemical synthesis*; D013057:Spectrum Analysis
chemical_list: D008024:Ligands; D008665:Metalloporphyrins