Picosecond Dynamics of Proton Transfers

Article abstract of DOI:10.1021/ja00309a004

The dynamics of proton transfer within an acid-base pair, which is created by a photoinduced electron transfer from an amine to a ketone, is investigated through picosecond absorption spectroscopy.Questions relating to molecular motion within the encounter complex and the distance dependence of proton transfer are addressed.Specifically, for substituted benzophenones and diphenylmethylamine, isotope and solvent dependence studies reveal that, although an acid-base pair is formed as an encounter complex, prior reorientation within the complex must take place before proton transfer.Other systems investigated include the transfer of a proton from the radical cation of N-methylacridan to the radical anions of benzophenone and anthraquinone as well as an intramolecular proton transfer for a molecule containing dimethylaniline linked to benzophenone by a methylene bridge.