Negative ion formation via laser desorption/ionization of C₆₀

The study of negative ion formation due to UV laser desorption/ablation are reported for C60. Negative ion formation is studied and provides information into the major mechanisms responsible for carbon cluster anion formation. Results will be compared to known photoelectron spectroscopy data as an aid in the ion formation mechanisms. Ab initio calculations, using the Gaussian 98 package, are used to give supporting information on the structures and electron affinities of small Cn clusters n ≤ B. The laser desorption negative ion mass spectra are reported and explained under the conditions of the experiment. Despite the importance and widespread use of laser desorption ionization (LDI), the physical mechanisms responsible for ion formation are not well understood. This study is devoted toward a better understanding of the physics of laser desorption/ionization.