PULSED-GLOW DISCHARGE MATRIX-ISOLATION METHOD FOR THE PRODUCTION AND TRAPPING OF ORGANIC IONS - APPLICATION TO PARA-DIMETHOXYBENZENE

A new technique for the production and trapping of organic ions in rare-gas matrices is introduced. A pulsed-glow discharge produces the ions which are repelled from a hemispherical wire-mesh grid held at a high positive (or negative) potential toward the cold (12 K) sample window of a closed-cycle cryostat where they are deposited. The radical cation of para-dimethoxybenzene (PDMOB) has been formed by this method in sufficient quantities to observe a number of its infrared spectral bands for the first time. The electronic absorption spectrum of the cation matches well with results obtained by gamma-irradiation of PDMOB in s-butylchloride matrices at 77 K and by oxidation of adsorbed PDMOB in Cu-exchanged montmorillonite clay. The introduction of CCl4 into the argon plasma gas stream significantly enhances the number of ions produced and trapped.