Conformational structures of 3-cyanoindole-(H2O)n (n = 0-2) by UV-UV hole-burning and IR-dip spectroscopy

- Excitation spectra of 3-cyanoindole (3CI) and its water clusters, 3CI-(H2O)n (n = 1 and 2), have been measured.
- Single conformer of 3CI and two conformers of 3CI-(H2O)1 and 3CI-(H2O)2 each were identified.
- Observed spectra are compared with the predictions of ab initio and density functional theory calculations.
- A water dimer-bridging structure of 3CI-(H2O)2 forming π-interaction with the indole ring is intriguing for the hydration of 3CI.
- This study can be regarded as stepping-stone for the understanding fundamental importance of the hydrogen-bonding effects associated with the CN stretch.