Ionization Potentials for the Titanium, Zirconium, and the Mixed Metal Met-Cars

Photoionization spectra of the titanium and zirconium metallocarbohedrene clusters (Met-Cars) of the stoichiometry Ti 8 - x Zr x C 12 ( x = 0−4, 8) have been investigated near threshold. Study of the photoionization efficiencies of these species at different photon energies led to a determination that the ionization potentials (IP's) for the titanium and zirconium Met-Cars, Ti 8 C 12 and Zr 8 C 12, are 4.40 ± 0.02 and 3.95 ± 0.02 eV, respectively. The IP's for the binary metal Met-Cars, Ti 8 - x Zr x C 12 ( x = 1−4), were also determined, and it was found that the IP decreases continuously from that of the pure titanium Met-Car toward that of the pure zirconium Met-Car as the number of substituting zirconium atoms increases.