Direct Visual Evidence for Neutral and Charged Hexaphyrin Aromaticity with and without Keto-Defect

We use density functional theory and time-dependent together with a set of extensive mul-tidimensional visualization techniques to characterize the influence of keto effect on charge distribution at ground state and electronic transitions for neutral and charged hexaphyrin aromaticity with and without keto-defect. It is found that the aromaticity is the key fac-tor to influence the ground state Mulliken charges distribution properties, other than the meso-aryl-substituted effect. But with the enhancement of the keto-defect, the distributionchanges of Mulliken charges on the hexaphyrin groups are larger than those on the pentaflu-orophenyl substituted groups, following with the aromaticity changes from nonaromatic toaromatic. Furthermore, through characterizing by transition density and charge difference density, direct visual evidence for neutral and charged aromaticity with and without keto-defect can be clearly derived, and the ability of charge transfer between units of monoradical (nonaromaticity) and singlet biradical (aromaticity) forms is much stronger than that of neutral forms.