Application of surface ionization to determine rate constant and activation energy of dissociation reactions of nitrogen base polyatomic molecules on W oxides

Adsorption and surface ionization of procaine, imipramine, amitriptyline and tetraethylammonium chloride on oxidized tungsten surface have been studied by the methods of voltage modulation and flux modulation under identical experimental conditions with the high‐vacuum mass‐spectrometric set up having a ‘black’ chamber with the walls cooled with liquid nitrogen. Rate constants and activation energies of dissociation reaction of initially adsorbed molecules by (C–C)β bonds with formation of radicals to be ionized have been defined. Also, rate constants and activation energy of desorption of these radicals as ions (CH3)2N+CH2 and (C2H5)2N+CH2 have been determined. Copyright © 2006 John Wiley & Sons, Ltd.