Collision-induced dissociation of Ti+n (n=2–22) with Xe: Bond energies, geometric structures, and dissociation pathways

Abstract

The kinetic energy dependence of the collision-induced dissociation (CID) of Ti+n (n=2–22) with Xe is studied by using a guided ion beam mass spectrometer. Examination of the CID cross section behavior over a broad collision energy range demonstrates that Ti+n clusters dissociate exclusively by sequential loss of Ti atoms. Bond energies of ionic titanium clusters, D0(Ti+n−1–Ti), are determined from measurements of the CID thresholds. D0(Ti+n−1–Ti) are found to change significantly as a function of cluster size, with local maxima at n=7, 13, and 19. This pattern of highly stable cluster ions suggests that titanium cluster ions favor icosahedral structures.