Magnetic Shielding Study of Bonding and Aromaticity in Corannulene and Coronene

Bonding and aromaticity in the bowl-shaped C5v planar D5h geometries of corannulene D6h geometry coronene are investigated using 3D isosurfaces 2D contour plots isotropic magnetic shielding σiso(r) and, for geometries, out-of-plane component tensor σzz(r). Corannulene both feature conjoined shielded “doughnuts” around a peripheral six-membered carbon ring, suggesting strong bonding interactions aromatic stability; deshielded region inside hub ring indicates that this is antiaromatic, more so corannulene. The switch from to shown enhance local aromaticities five- rings; these factors, addition strain reduction, favour geometry. most least bonds turn out be spoke bonds, respectively. higher π electron activity over supported by σzz(r) planes 1 Å above respective molecular planes; findings about somewhat unexpected, given current studies indicate next no currents bonds.