Knowledge Bank

The vibrational spectrum of the ternary cluster cation of aniline-water-toluene in a supersonic jet has been measured by infrared depletion method in the NH and OH stretching region. Three bands were observed at 3722, 3634 and $3295cm-1$. The analysis of the vibrational spectrum showed that two NH bonds of aniline interact with water and toluene in the cluster cation. The band at $3295cm-1$ was assigned to the stretching vibration of NH of aniline cation interacting with toluene, whereas other two bands were assigned to the symmetric and anti-symmetric stretching vibrations of free OH of water. When the cluster absorbs the infrared photon, it dissociated into two fragments. There are two possible dissociation path of this cluster. 1) $AWT+\to AW++T$ and 2) $AWT+\to AT++W$ The branching ratio of this reaction $AW+/AT+$ was measured for three different bands, and we obtained 0.49 for the NH stretching vibration and 0.37 and 0.38 for the OH stretching vibrations. This results suggest that there is a fast energy transfer from the NH stretching vibration to the hydrogen bond between NH and toluene which enables the vibrational mode dependence of the predissociation.