In an additional control experiment, a representative palkoxyphenyl trifluoromethyl diazirine (which is known to undergo C-H insertion to cyclohexane in >90% yield, under both photochemical and thermal stimulation, and which has Tonset and Tpeak values almost identical to those of 1 ) was irradiated with red light in an identical setup to that described above. This control molecule did not activate at all under the conditions of the experiment, and clean recovered starting material was recovered following multiple irradiation cycles (refer to the ESI for details). These results rule out any thermal activation in the experiment shown in Fig. , and establish that diazirine 1 was activated through two-photon excitation.