The collision induced reactions of cationic chromium clusters with deuterium

The kinetic energy dependencies of the reactions of Cr+n (n=2-12) with deuterium are studied by using a guided ion beam mass spectrometer. A simple molecular orbital bonding model for small ionic chromium clusters suggests that the atoms are predominantly bound by the 4s electrons with the 3d electrons in the stable dS configuration. Deuterium contributes one s electron giving the even numbered ion clusters a closed shell, more stable configuration and the odd numbered ion clusters an open shell, less stable configuration. The reactivities of the clusters show an even-odd oscillation with the even numbered clusters showing greater reactivities than the odd sized clusters. These results are consistent with and support the s orbital electronic bonding model for small ionic chromium clusters.