Reactions of laser-ablated Y and La atoms, cations and electrons with O-2.Infrared spectra and density functional calculations of the MO, MO+, MO2, MO2+, and MO2- species in solid argon

Laser-ablated Y and La condensed with O-2 in excess argon formed small meta l oxides, cations, and anions, which were identified from isotopic substitu tion and density functional frequency calculations. In accord with gas phas e thermochemistry, the OYO and OLaO molecules are more weakly bound than YO and LaO, on the basis of vibrational frequencies, and their symmetric stre tching modes are unusually intense. The bent OYO- and OLaO- anions, the cyc lic Y(O-2)(+) and La(O-2)(+), and linear OLaO+ cation isomers are character ized. The (O-2)MO and MO3 isomers are also observed.