Self-assembled alkyl monolayers on Si (111) were exposed to low doses of slow (upsilon approximate to 6.6 x 10(5) m/s approximate to 0.3 upsilon(Bohr)) , highly charged ions, like Xe41+ and Th73+. Atomic force microscope images show craters from single ion impacts with diameters of 50-63 nm. Emission of secondary ions by highly charged projectiles was monitored by time-of-flight secondary ion mass Spectrometry (TOF-SIMS). TOF-SIMS data give insights into the dependence of electronic desorption effects on the projectile charge state. We discuss the potential of highly charged projectiles as tools for materials modification on a nanometer scale.