Reaction of Molecular-Negative Ion in Acetonitrile.

Abstract

The molecular-negative ions of acetonitrile are formed by ionizing collision with long-lived highly excited atoms. It was observed that the intensity of the CD₃CN^- ions increases with second order of a CD₃CN gas pressure at a relatively low pressure, with an increase of CD₃CN gas pressure it disappears with third order of the pressure. Assuming the simple bimolecular reaction between CD₃CN^- and acetonitrile molecule for the disappearance reaction of CD₃CN^-, the rate constant was determined to be 6.7 × 10^-9 cm³/molecule·s. The excitation cross section for the formation of long-lived highly excited atoms from acetonitrile molecule by electron impact was estimated to be 4 × 10^-21 cm² at 100 eV electron energy. In binary mixture of acetonitril-hydrogen, it is also observed that CD₃CN^- ions were formed by ionizing collision with long-lived highly excited states of hydrogen molecule.