Ring currents and magnetisability in C60

✍ Scribed by R. Zanasi; P.W. Fowler

• Book ID: 103033362
• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 818 KB
• Volume: 238
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)00437-9

✦ Synopsis

A distributed-origin coupled Hartree-Fock method is used to compute the current density induced in C6o by an external magnetic field, and hence to plot the 7r ring currents and obtain ab initio values of the total magnetisability and nuclear magnetic shielding. Paramagnetic ring currents are associated with pentagons, and interpreted as consequences of strong, local circulations about the formal double bonds of the C6o framework. The calculated total magnetisability of -370 cgs ppm is strongly diamagnetic and in agreement with the previous extrapolated ab initio result and with an experimental measurement. The calculated central shielding of +12 ppm is in qualitative agreement with the previous extrapolation and the measured encapsulation shift for 3He in C6o. It is concluded that C6o is diamagnetic, but that the interpretation of this diamagnetism as a sign of three-dimensional aromaticity is problematic.