Suppression of decomposition of aniline cation in intense laser fields by cluster formation with ammonia molecules

Abstract

Mass-selected aniline cations and [aniline-(NH3)n]+ (n=1 and 2) cluster ions are exposed to the femtosecond laser fields (λ∼395 nm,I∼4×1015 W/cm2) and the nanosecond laser fields (λ=532 nm,I∼2.7×1010 W/cm2) by using a tandem type time-of-flight mass spectrometer. In the case of the bare aniline cation, the decomposition forming the five-membered ring compound, cyclopentadienyl cation (C5H6+), dominantly proceeds in both the femtosecond and nanosecond laser fields. When one or two ammonia molecules are attached to the aniline cation, the decomposition is significantly suppressed. This suppression was interpreted in terms of an intermolecular energy flow through the hydrogen bonding.