Ab initio determination of the induced ring current in aromatic molecules

The aromatic ring current shieldings (ARCS) approach is a new method to det ermine the strength of the induced ring current which is related to the mol ecular aromaticity. In the ARCS method, the strength of the induced aromati c ring current and the size of the current ring are obtained from nuclear m agnetic shieldings calculated in discrete points along a line perpendicular to the molecular plane starting at the center of the molecule. The induced ring currents are used to determine the relative degree of aromaticity for benzene, furan, pyrrole, cyclohexane, cyclohexadiene, thiophen, p-benzoqui none, cyclopentadienide anion, cycloheptatrienyl cation, 1,4-dihydronaphtha lene, and prophin.