The aniline-water and aniline-methanol complexes in the S1 excited state

We report an experimental and theoretical study on the properties of the aniline-water and aniline-methanol jet cooled complexes. In both complexes the ligand (H2O or CH3OH) is hydrogen bonded to aniline, the interaction taking place at the lone pair of the nitrogen, in the amino group. The S1 ← S0 electronic excitation spectrum in both cases exhibits a very broad and weak band, blue shifted with respect to the origin band of aniline by ≈700 cm−1. Ab initio calculations, at different levels of theory with the cc-pvdz electronic basis set, were performed on aniline-water and predict a strong binding energy decrease in the excited state and a large change in geometry, in agreement with experimental results.