Laser-Induced Fluorescence Studies of Large and Small Molecular Cations Produced by Using Electron Bombardment in a Free Jet Expansion

Article abstract of DOI:10.1021/j150643a033

Laser-induced fluorescence (LIF) excitation spectra have been obtained for a number of ions produced by electron impact in a free jet expansion.The ions observed include N2⁺, CO2⁺, C6F6⁺, C6F5H⁺, C6F3H3⁺, and C4H2⁺.In all cases "cold" laser excitation spectra have been obtained.For the simpler ions information about rotational distributions is available, while for the large ions the elimination of hot bands, sequence congestion, extensive rotational contours, etc., makes their spectra much easier to interpret.Under certain circumstances Penning ionization in the expansion effectively competes with direct ionization via electron impact.Some satellite structure is obtained in the C6F6⁺ spectrum which may be ascribed to C6F6⁺.Ar.