1. Interestingly, in 3T-b, breaking these bonds quickly shifts the molecule from an inverted ST order to a normal region, while the opposite effect is observed for 3T-c and 3T-d. As expected, when two or four central bonds are broken and the system symmetry is reduced, the lowest-lying singlet state gains significant oscillator strength. However, breaking all six bonds connecting the borazine core to the triangulene rim restores D 3h symmetry, making the lowest energy singlet state optically forbidden (see SI Section S4).