Reaction of molecular-negative ion in acetonitrile

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 x 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 x 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. (author)