title: Structural isomers of Ti₂O₄ and Zr₂O₄ anions identified by slow photoelectron velocity-map imaging spectroscopy.
abstract: High-resolution anion photoelectron spectra are reported for the group 4 metal dioxide clusters Ti2O4(-) and Zr2O4(-). Slow photoelectron velocity-map imaging (SEVI) spectroscopy of cryogenically cooled, mass-selected anions yields photoelectron spectra with submillielectronvolt resolution, revealing extensive and well-resolved vibrational progressions. By comparison of the spectra with Franck-Condon simulations, we have identified the C(2v) and C(3v) isomers as the ground states of Ti2O4(-) and Zr2O4(-) anions, respectively. Minor contributions from the C(2h) isomer of Ti2O4(-) and the C(2v) isomer of Zr2O4(-) are also seen. The SEVI spectra yield upper bounds for the adiabatic detachment energies, as well as vibrational frequencies for various modes of the neutral Ti2O4 and Zr2O4 species.
authors.affiliation: Department of Chemistry, University of California , and Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Jongjin B
authors.initials: JB
authors.lastname: Kim
authors.forename: Marissa L
authors.initials: ML
authors.lastname: Weichman
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Neumark