THE ALLENE DICATION - CALCULATED AND MEASURED SINGLET-ELECTRONIC-STATE ENERGIES

Vertical double-ionization energies of the allene molecule to singlet electronic states of the dication have been measured by double-charge- transfer spectroscopy, and are in excellent agreement with values pred icted using a semi-empirical MSX alpha-based method. The present data, when combined with those of a previous investigation in which energie s to triplet states were determined, provide comprehensive electronic- state information for the allene dication in a range up to ca. 12 eV a bove that for the triplet ground state.