Excited-state intermolecular proton transfer reactions of 7-azaindole(MeOH)(n) (n = 1-3) clusters in the gas phase: on-the-fly dynamics simulation.
Résumé
Ultrafast excited-state intermolecular proton transfer (PT) reactions in 7-azaindole(methanol)(n) (n = 1-3) [7AI(MeOH)(n=1-3)] complexes were performed using dynamics simulations. These complexes were first optimized at the RI-ADC(2)/SVP-SV(P) level in the gas phase. The ground-state structures with the lowest energy were also investigated and presented. On-the-fly dynamics simulations for the first-excited state were employed to investigate reaction mechanisms and time evolution of PT processes. The PT characteristics of the reactions were confirmed by the nonexistence of crossings between S(pipi*) and S(pisigma*) states. Excited-state dynamics results for all complexes exhibit excited-state multiple-proton transfer (ESmultiPT) reactions via methanol molecules along an intermolecular hydrogen-bonded network. In particular, the two methanol molecules of a 7AI(MeOH)(2) cluster assist the excited-state triple-proton transfer (ESTPT) reaction effectively with highest probability of PT.