Table 1. Calculated NICS values for the C₃N₂/C₂P₃ units of 4a–4d at the M06-2X/def2TZVPP//M06-2X/def2SVP level of theory.

C3N2/C2P3	4a	4b	4c	4d	5a	C6H6/CBD a
NICS(0)	–7.08/–10.19	–7.29/–10.31	–7.29/–10.31	–6.77/–10.37	–7.57/–9.95	–7.53/33.21
NICS(1)	–5.94/–10.18	–6.11/–10.28	–6.11/–10.23	–5.64/–10.21	–6.29/–9.58	–10.19/21.09
NICS(2)	–2.43/–5.51	–2.53/–5.21	–2.53/–5.53	–2.36/–5.52	–2.52/–5.12	–5.22/4.98

^aCBD (cyclobutadiene).