Photoelectron spectroscopy and electronic structure of Met-Car Ti8C12

Photoelectron spectroscopy experiments are performed on a metallocarbohedrene, Ti8C12-, to obtain electronic structure information. The Ti8C12- anion is produced by laser vaporization of a titanium carbide target. The spectra of Ti8C12- consist Of an intense threshold feature and two weaker features followed by a gap and more higher energy features. The electron affinity of Ti8C12 is found to be 1.05 (+/-0.05) (adiabatic) and 1.16 (+/-0.05) eV (vertical). The surprisingly low electron affinity and the observed electronic features are interpreted using theoretical electronic structure information. The current experiments provide hitherto the most direct spectroscopic information on the Met-Car Ti8C12.