PHOTOELECTRON-SPECTROSCOPY OF THE HALOGEN OXIDE ANIONS FO-, CLO-, BRO-, IO-, OCLO-, AND OIO-

The 351 nm photoelectron spectra of FO-, ClO-, BrO-, IO-, OClO-, and OIO- are reported. The spectra of the halogen monoxides display transitions to both spin-orbit states of the (2)PI(i) ground state neutrals. Anion vibrational frequencies are observed in the spectra and bond lengths are obtained for the anions from Franck-Condon simulations. Spectra of the halogen dioxides display two active vibrational modes-the symmetric stretch and the bend. Anion symmetric stretching frequencies and normal coordinate displacements from the corresponding neutral are reported. Adiabatic electron affinities found for the halogen oxides are 2.272(6) eV (FO), 2.276(6) eV (ClO), 2.353(6) eV (BrO), 2.378(6) eV (IO), 2.140(8) eV (OClO), and 2.577(8) eV (OIO). The difference between the neutral and anion dissociation energies [D0(XO) - D0(XO-)] is reported for each of the halogen monoxides. Anion heats of formation (298 K) are also determined.