MATRIX-ISOLATION SPECTROSCOPY OF NA ATOMS DEPOSITED AS NA+ IONS

The results of matrix isolation experiments of Na atoms deposited as N a+ ions in Ar matrices are reported. The optical absorption spectra in clude features which were observed for the first time in Na/Ar matrice s prepared using laser ablation of Na metal [S. Tam and M. E. Fajardo, J. Chem. Phys. 99, 854 (1993)]. In that study, the observed novel tra pping sites and improved atomic isolation efficiency were attributed t o the high kinetic energy of the fast Na atoms produced by laser ablat ion. These new results challenge that interpretation and demonstrate t hat, at least for Ar matrices, the same effects can be reproduced by t he deposition and subsequent neutralization of Na+ ions.