Aromatic conjugation pathways in porphyrins

• Jun-ichi Aihara

• Eiichi Kimura

• Tadeusz Marek Krygowski

Abstract

The π-current density induced in a polycyclic π-system is strongly dependent on molecular geometry, so that information on main aromatic pathways cannot be extracted straightforwardly from the π-current density. Using our graph theory of aromaticity and ring-current diamagnetism, we re-interpreted the π-current densities and aromatic stabilization energies of porphyrins consistently and found that main pathways of π-electron circulation along the macroscopic ring are not those of aromatic stabilization. Four five-site circuits instead proved to be the main origin of aromaticity in porphyrins. In general, currents are induced in all possible circuits in a π-system. Superposition of all these circuit currents gives rise to the apparent bifurcation of the π-current across each pyrrolic unit. Local π-currents induced in pyrrolic rings represent those induced in the corresponding five-site circuits.

Journal

• Bulletin of the Chemical Society of Japan

  Bulletin of the Chemical Society of Japan 81 (7), 826-835, 2008

  Tokyo : Chemical Society of Japan

Keywords

• General Chemistry

Details

• CRID: 1521417754669025024
• NII Article ID: 10021076665
• NII Book ID: AA00580132
• ISSN: 00092673
• ISSN: 13480634
• DOI: 10.1246/bcsj.81.826
• NDL BIB ID: 9573867
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I9573867
• Web Site: https://academic.oup.com/bcsj/article-pdf/81/7/826/56270132/bcsj.81.826.pdf
• Text Lang: en
• NDL Source Classification:
  • ZP1(科学技術--化学・化学工業)
• Data Source:
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN