Electron-induced “localized atomic reaction” (LAR): Chlorobenzene adsorbed on Si(111) 7×7

Abstract

Electron-induced reaction of chlorobenzene (ClPh) adsorbed on silicon [Si(111)7×7] is shown by scanning tunneling microscopy (STM) to result in “localized atomic reaction” (LAR), imprinting Cl as chemically-bound Cl–Si on the surface. Voltage pulses of −4 V from the STM tip give LAR restricted to the site of electron impact. Delocalized electron impact imprints the self-assembled pattern of ClPh(ad) on the surface as Cl–Si. The imprint is found to be on the same area of the unit cell as ClPh(ad), but at adjacent atomic sites. The occurrence of LAR is ascribed to a concerted reaction; this can only occur if the new bond (Cl–Si) is directly adjacent to the old one (Cl–Ph).