Electron spin resonance studies of (ScO)-Sc-45-O-17, (YO)-Y-89-O-17, and (LaO)-La-139-O-17 in rare gas matrices: Comparison with ab initio electronicstructure and nuclear hyperfine calculations

The first nuclear hyperfine measurements of O-17 (I=5/2) have been made for Sc O-17, (YO)-O-17 and (LaO)-O-17 in their X (2)Sigma ground electronic st ates. These metal oxide radicals were generated by the pulsed-laser vaporiz ation of the metals in the presence of O-16(2)/O-17(2) and trapped in neon and argon matrices for electron spin resonance investigations. The fully re solved A tensors of the metal and O-17 were compared with ab initio theoret ical calculations-a comparison previously reported only for the ScO radical . The computational methods employed were unrestricted Hartree-Fock, densit y functional theory (DFT), and restricted open-shell Hartree-Fock. Having t he metal and O-17 hyperfine interactions available has permitted a more tho rough description of the electronic structure and charge distribution in th ese metal oxide molecules. An electronic structure comparison with the AlO, GaO, and InO radicals has also been made. Reasonably good agreement betwee n the observed and calculated values of A iso and A dip were achieved with the DFT method providing the closest agreement. (C) 1999 American Institute of Physics. [S0021-9606(99)01311-2].