REACTIONS OF LASER-ABLATED NICKEL ATOMS WITH DIOXYGEN - INFRARED-SPECTRA AND DENSITY-FUNCTIONAL CALCULATIONS OF NICKEL OXIDES NIO, ONIO, NI2O2, AND NI2O3, SUPEROXIDE NIOO, PEROXIDE NI(O-2), AND HIGHER COMPLEXES IN SOLID ARGON

Laser-ablated nickel atoms react with dioxygen to form the primary oxi des NiO and ONiO, some of which combine to form the secondary oxides N i2O2 and ONiONiO during condensation in excess argon at 10 K. The inse rtion product dioxide ONiO is linear based on natural nickel and O-18 isotopic substitution and DFT calculations. Annealing produces the cyc lic adducts reported in earlier thermal nickel experiments and the new NiOO superoxide species, which are characterized by isotopic shifts a nd DFT structure and frequency calculations. In addition, dioxygen com plexes with NiO and ONiO were also observed. Finally, the matrix provi des sharp bands and the resolution to observe nickel isotopic splittin gs which characterize the Fermi-resonance interaction in the ONiOO and (O-2)Ni(O2) molecules.