COLLISIONS OF POLYATOMIC IONS WITH SURFACES

Surface-induced dissociation (SID) of polyatomic ions is reviewed. Instrumentation is described, including hybrid, tandem quadrupole and tandem time-of-flight instruments built especially to study polyatomic ion-surface collision phenomena. In addition, in-line devices that allow SID to be performed on conventional tandem mass spectrometers are noted, as are experiments which utilize ion cyclotron resonance instruments. The extent of energy deposition accompanying surface collisions is characterized and compared with data from gaseous collisions at non-zero scattering angles. The large internal energies available through SID are shown to facilitate structural characterization of molecular ions of polynuclear aromatic hydrocarbons and peptides. Applications to ion strucutre and chemistry are also illustrated. Emphasis is given to competing ion-surface collision phenomena, including charge-changing collisions and ion-surface reactive collisions. These latter processes are shown to provide information on adsorbates and to be thermochemically controlled. When certain projectile ions, especially small fluorocarbons, undergo charge exchange with surface adsorbates, they are released from the surface as ions. The influence of the nature of the surface on these processes and on SID is discussed. Current trends in research on ion-surface collisions are identified. © 1990.