Infrared depletion spectroscopy of aniline(H2O)n+ (n=2–6) cluster cations

The vibrational spectra of aniline(H2O)n+ (n=2–6) in the 3 μm region have been measured. Cluster cations were generated by near resonant two-photon ionization of neutral clusters, and magic numbers were observed at n=4 and 5. frared spectra were investigated with the aid of the B3LYP/6-31++G** method. It was found that several isomers coexisted. A linear type cluster is the main component for the small clusters. A ring type cluster in which the NH2 group of aniline and water molecules form a ring appears in the spectrum of the clusters of n=3, and it becomes the main component in the clusters of n⩾4.