Proton transfer between phenol and ammonia in ground and excited electronic states

Abstract

Ab initio calculations consider the H-bonded complex between phenol and ammonia. The transfer of a proton in the ground electronic state, which would form PhO − … +HNH 3, is highly disfavored. However, the situation changes dramatically in the first excited singlet state where the proton transfer potential develops a second minimum, competitive in energy with the neutral pair PhOH … NH 3. Following electron ejection, the radical cation complex, PhOH + … NH 3, contains a very flat proton transfer potential connecting PhOH ·+ … NH 3 with PhO · … H +NH 3. Addition of more ammonia molecules further stabilizes the proton-transfered PhO · … H +NH 3 configuration.