Fig. 6. AdNDP bonding pattern for doubly antiaromatic
B2N2. ON = occupation number
The bonding pattern of B3N3 is slightly
different, 1c-2e corresponding to N-lone pairs are localized, in
agreement with NICSzz isosurface showed previously where
local diatropic zones are found. Additionally, 2c-2e corresponding to
B-N σ bonds are localized. Finally, three 6c-2e delocalized π bonds are
found fulfilling Hückel’s rule, which indicates an aromatic compound.
This pattern is similar to all remaining aromatic and antiaromatic
BxNx (x = 3 – 6) clusters (See Fig. S4
– S6 in the SI). The bonding pattern for non-aromatic
B7N7 cluster presents fourteen 2c-2e σ
bonds. The lone pair of nitrogens can no longer be located, so the
pattern reveals 14 π bonds in agreement with bond equalization for
non-aromatic BxNx clusters. This same
pattern is observed for clusters with x = 8 – 11 BN moieties (See Fig.
S6 – S9 in SI).