Conformational structures of 3-cyanoindole-(H2O)n (n = 0–2): Franck–Condon simulations

Franck–Condon (FC) simulations were applied to 3-cyanoindole (3CI) and its water clusters, 3CI-(H2O)n (n = 1 and 2), for the first time to determine their molecular structures using mass-selected resonant two-photon ionization (R2PI) and UV–UV hole-burning (UVHB) spectroscopy. R2PI and UVHB spectra were compared with the results of Franck–Condon (FC) simulations that can determine the change in a molecular geometry of 3CI-(H2O)n (n = 0–2) on electronic excitation. It was found that the most stable structure for each 3CI-(H2O)n (n = 0–2) was identified and their excited state geometries were little influenced upon excitation.