X-ray analysis of bis(
p-fluorophenyl)methyl cation bearing a 2,6-bis(
p-tolyloxymethyl)benzeneligand showed a symmetrical structure (10-C-5) where the two C-O distances are identical, although thedistance (2.690(4) Å) is longer than those (2.43(1) and 2.45(1) Å) of 1,8-dimethoxy-9-dimethoxymethylanthracene monocation, which was recently reported by us. However, X-ray analysis of the more stablearomatic xanthylium cation with the same benzene ligand showed the tetracoordinate carbon structurewhere only one of the two oxygen ligands is coordinated with the central carbon atom. These results clearlyindicate that the carbocations (10-C-5) bearing the sterically flexible benzene ligand were quite sensitiveto the electronic effect on the central carbon atom. The electron distribution analysis by accurate X-raymeasurements and the density functional calculation on the initially mentioned bis(
p-fluorophenyl)methylcation clearly show that the central carbon atom and the two oxygen atoms are bonded even if the bondis weak and ionic based on the small value of the electron density (
(
r)) and the small positive Laplacianvalue (
2(
r)) at the bond critical points.