Five ketenes, phenyl (ethyl) ketene, phenyl (methylthio) ketene, diphenylketene, pentafluorophenylketene, and 1-naphthylketene, were generated flash photolytically and solvent isotope effects (H2O vs. D2O) on their hydroxide-ion-catalyzed hydration in aqueous solution were determined. The values obtained are all weakly inverse and closely similar (k HO/k DO= 0.76-0.97), as expected for these fast, hydroxide-ion-consuming reactions, ...
