Infrared depletion spectroscopy of aniline-NH3 and aniline-NH3+ clusters in a supersonic jet

The vibrational spectra of aniline-NH3 and aniline-NH3+ clusters in the NH stretching vibration region have been measured using infrared depletion spectroscopic techniques combined with mass spectrometry. There are two strong absorption bands at 3354 and 3479 cm−1 in the spectrum of aniline-NH3. They have been assigned to the stretching vibrations of the NH2 group of aniline. One of the NH bonds of aniline interacts with the lone pair of the nitrogen atom of NH3 through the hydrogen bond. The spectrum of aniline-NH3+ gives only one strong absorption at 3419 cm−1. This band has been assigned to the stretching vibration of the free NH bond of aniline. The hydrogen bond in the cation cluster has been found to be much stronger than that in the neutral cluster.