Electron spin resonance studies of \u3csup\u3e45\u3c/sup\u3eSc\u3csup\u3e17\u3c/sup\u3eO,\u3csup\u3e89\u3c/sup\u3eY\u3csup\u3e17\u3c/sup\u3eO, and \u3csup\u3e139\u3c/sup\u3eLa\u3csup\u3e17\u3c/sup\u3eO in rare gas matrices: Comparison with ab initio electronic structure and nuclear hyperfine calculations

The first nuclear hyperfine measurements of 17 O -€Š(I=5/2) have been made for Sc 17 O ,-€Š Y 17 O and La 17 O in their X-€Š 2 Σ ground electronic states. These metal oxide radicals were generated by the pulsed-laservaporization of the metals in the presence of 16 O 2 / 17 O 2 and trapped in neon and argon matrices for electron spin resonance investigations. The fully resolved Atensors of the metal and 17 O were compared with ab initiotheoretical calculations-€”a comparison previously reported only for the ScO radical. The computational methods employed were unrestricted Hartree-Fock, density functional theory(DFT), and restricted open-shell Hartree-Fock. Having the metal and 17 O hyperfineinteractions available has permitted a more thorough description of the electronic structure and charge distribution in these metal oxide molecules. An electronic structure comparison with the AlO, GaO, and InO radicals has also been made. Reasonably good agreement between the observed and calculated values of A iso and A dip were achieved with the DFT method providing the closest agreement