The shell structure of pi ring currents in the expanded porphyrin amethyrin.
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.
Steiner
Erich
E
School of Biosciences, University of Exeter, UK.
Fowler
Patrick W
PW
D004583:Electrons; D008956:Models, Chemical; D008958:Models, Molecular; D011166:Porphyrins / Q000737:chemistry*
D011166:Porphyrins