Collision-Induced Dissociation of Nitrobenzene Molecular Cations at Low Energies by Crossed-Beam Tandem Mass Spectrometry

Abstract

The dynamics of the collision-induced dissociation (CID) of the nitrobenzene molecular ion have been investigated in the energy range of 3 eV−50 eV in the center-of-mass (CM) reference frame using a crossed-beam tandem hybrid mass spectrometer−supersonic molecular beam instrument. At these collision energies the dominant CID channel is loss of NO2 from the molecular ion and contribution from competing channels is very small. At 3.1 eV collision energy, fragment ions, C6H5+, are fully backward scattered and as collision energy is increased the most probable scattering angle moves in the forward scattering region but remains above zero up to 50 eV energy. These results suggest that small impact parameter impulsive collisions dominate this CID process in the low collision energy range. The energy transfer in the collisional activation step does not change significantly with increase in collision energy and corresponds to about 0.6 eV above the thermochemical threshold even though the molecular ions were form...