title: The shell structure of pi ring currents in the expanded porphyrin amethyrin.
abstract: Direct ab initio mapping of induced current density in the pi system of the expanded porphyrin amethyrin shows a picture at variance with the conventional 4npi ascription of antiaromaticity. The ipsocentric orbital model interprets the pattern of currents as a superposition of shell contributions: an intense paratropic ring current concentrated on the inner 20-site cycle, counteracted by a weaker diatropic circulation on a 24-site conjugation pathway and a combination of local 5-site diatropic circulations on the six pyrrolic rings.
authors.affiliation: School of Biosciences, University of Exeter, UK.
authors.forename: Erich
authors.initials: E
authors.lastname: Steiner
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Fowler
mesh_terms: D004583:Electrons; D008956:Models, Chemical; D008958:Models, Molecular; D011166:Porphyrins / Q000737:chemistry*
chemical_list: D011166:Porphyrins