With the indication that both thermal and photochemical AO scission might be non-homolytic, we revisited zero-force DFT calculations and performed a potential energy surface scan of the N-O stretching coordinate. Surprisingly, we found that thermal N-O bond rupture of AO led to a rearrangement reaction that included an H-transfer from C to O (Figure ). The N-O bond PES scan showed that the dihedral angle (C-O-N-C) decreased from 174 to 90 ° (Figure ), which led the molecule through a 6-membered transition state during the N-O bond rupture and H transfer from C to O.