Unraveling the possible isomers of CH4CN+ and CH2CN+ through FT-IR matrix-isolation spectroscopy of mass-selected ions and DFT theory.

The positive molecular ions of astrophysical interest--protonated and fragment ions of acetonitrile are investigated by means of mass-selective deposition in Ne matrices and FT-IR spectroscopy in the region of 500-4000 cm(-1). Ionic species are generated by electron impact ionization with parallel fragmentation and) ion-molecule reactions of an acetonitrile precursor, CH3CN (CD3CN). The ions are deposited in Ne matrices together with an excess of electrons to prevent a buildup of space charge.

Thermally stimulated exoelectron emission from solid neon.

In spite of the negative electron affinity of Ne atoms, appreciable concentrations of electrons can be trapped in solid neon layers formed by depositing the gas on a cold substrate with concurrent electron irradiation. These are trapped at defect sites, and can be promoted into the conduction band in an annealing experiment. They can then recombine with positive charges producing vacuum ultraviolet "thermoluminescence," but can also be extracted from the solid, and detected as an "exoelectron" current.