Spectroscopic and theoretical studies of jet-cooled 3-cyanoindole ammonia clusters in the gas phase

Abstract

The structural information of 3-cyanoindole ammonia cluster, 3CI-(NH3)(1), in molecular beams was investigated in the gas phase. We obtained UV-UV hole-burning spectrum (UV-UV HB) to determine the number of conformers present in the molecular beams and examine their spectral features. As a result, single conformer of 3CI-(NH3)(1) was observed in the mass-selected one-color resonant two-photon ionization (1C-R2PI) spectroscopy. The origin band of 3CI-(NH3)(1) in the R2PI spectrum is redshifted by 122 and 71 cm(-1) compared to those of the 3CI monomer and 3CI 1:1 water cluster, 3CI-(H2O)(1), respectively. The fully optimized geometries, relative energies, transition energies, binding energies, and electrostatic potential (ESP) of the 3CI monomer, 3CI-(H2O)(1), and 3CI-(NH3)(1) clusters were calculated at the B3LYP and TD-B3LYP methods with the 6-311++(d,p) basis set. The observed spectra are compared with the predictions of time-dependent density functional theory calculations.