title: New tetrapyrrolic macrocycles. 18 and 20 pi electron homoporphyrins.
mesh_terms: D008665:Metalloporphyrins / Q000138:chemical synthesis; D008722:Methods; D008968:Molecular Conformation; D009532:Nickel; D011166:Porphyrins / Q000138:chemical synthesis*; D011758:Pyrroles / Q000138:chemical synthesis*
chemical_list: D008665:Metalloporphyrins; D011166:Porphyrins; D011758:Pyrroles; D009532:Nickel