Photoionization and density functional theory study of clusters of acetone containing an alkali metal atom, M((CH3)2CO)n (M=Li, Na): intracluster electron transfer from metal to acetone in 1:1 complexes

Ionization threshold energies of clusters of Li and Na atoms solvated by acetone have been determined by laser photoionization. The thresholds for 1:1 complexes agree well with calculated adiabatic ionization potentials based on density functional theory. The structures and charge distributions obtained from the calculation show that electron transfer from the alkali atom to acetone occurs more efficiently in Li((CH3)2CO) than in Na((CH3)2CO). This difference in the extent of electron transfer can be understood by a consideration of the orbital overlap between the metal np and O2p orbitals and the sp hybridization on the alkali atom.