Reactions of size-selected metal cluster ions

Reactions of small thermalized cationic nickel clusters with carbon monoxid e were investigated in a guided molecular-beam experiment. Employing this t echnique, an efficient nickel carbonyl cluster formation and even bond brea king of the C-O bond was observed. The stability of the nickel carbonyl com plexes was measured by exciting these complexes with laser light showing an efficient photodesorption of the carbon ligands. Additionally, a very stro ng influence of the kinetic energy of metal clusters on the reaction yield was observed. The structure of the saturated nickel carbonyl complexes is d iscussed using simple electron-counting rules. The measured results show an excellent agreement with the predicted saturation numbers and thus confirm the structural attributions.