The C–O bond dissociation of naphthoxymethyl compounds in the higher triplet excited state using two-color two-laser flash photolysis

C–O bond dissociation of naphthoxymethyl compounds NpO–CH2R (Np = α- or β-naphthalene moiety, R = Ph or Me) in the higher triplet excited state (Tn, n ⩾ 2) was investigated using two-color two-laser flash photolysis. The C–O bond dissociation was found to occur with quantum yields (Φ) of 0.06 and 0.07 for α- and β-NpO–CH2Ph(Tn), respectively. With the use of reported data on C–O bond cleavage in NpCH2–OPh(Tn) and NpCH2–OMe(Tn), it was concluded that Φ is related to the Tn-state lifetime and the energy barrier between the Tn state and dissociative potential surfaces.