Ring currents and magnetic properties of pyracylene

✍ Scribed by P.W. Fowler; R. Zanasi; B. Cadioli; E. Steiner

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 709 KB
• Volume: 251
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(96)00120-0

✦ Synopsis

A distributed-origin coupled Hartree-Fock method is used to compute the current density induced in the pyracylene (cyclopent[ fg] acenaphthylene) molecule by an extemal magnetic field, and hence to plot the ~r ring currents and obtain ab initio values of the total magnetisability, ~3C and ~H nuclear magnetic shieldings. The calculated map shows paramagnetic ring currents over the pentagons and diamagnetic circulation around the central naphthalenoid unit of pymcylene, and accounts semi-quantitatively for the measured difference in chemical shift between protons attached to the pentagons and hexagons of this molecule.