- The photochemistry of 1-naphthol following its electronic excitation in aqueous solution was investigated by a single-photon counting apparatus. It was found that following the proton dissociation the excited naphtholate anion decays non-exponentially with a t − sol1 2 dependence over time. This we attribute to a self-quenching reaction of the naphtholate anion by its geminate proton. The quenching rate on contact is 3.5 × 10 10 s −1 . We also found that some of the protons interact adiabatically with a geminate recombination rate in D 2 O fo 8 × 10 9 s −1 . The time-dependent escape probability of the naphtholate iopn-par was sam;ed by carrying out the experiment in presence of a proton scavenger. We show that the leading term in the ultimate scavenging probability is given by the time integral of the homogeneous scavenging rate of the isolated pair at relative long times following its creation.