To unravel the origin of the observed effects, the dissociation mechanism of the carbamoyloxime mechanophores was investigated with a series of intermediate trapping experiments (Figure ). First, AO was heated to its dissociation temperature at 90 °C for 1 h in the presence of the spin trap 5,5dimethyl-1-pyrroline-N-oxide (DMPO) to scavenge and label any radical intermediates. Over the course of the experiment, the nitrile formed expectedly but the DMPO concentration remained constant and no indicative shifts in the 1 H NMR spectrum were discerned that hinted towards its reaction with a radical intermediate (Figure , Figure ). In a parallel experiment, the photochemical AO scission was investigated by irradiation of AO at 254 nm for 1 h in the presence of DMPO, which also cleanly produced the nitrile but did not reveal any trapped radicals.