PHOTOIONIZATION AND DENSITY FUNCTIONAL STUDY OF ALKALI METAL-ACETONE COMPLEXES ELECTRON TRANSFER FROM THE METAL ATOM TO THE MOLECULE Hironori Tsunoyama, Keijiro Ohshimo, Yoshihiro Yamakita, Fuminori Misaizu and Koichi Ohno Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan Complexes consisting of an alkali metal atom (M) and acetone molecules are studied by photoionization mass spectroscopy and by calculations based on density functional theory (DFT). Ionization potentials (IPs) of M(acetone) determined experimentally are in good agreement with those obtained from calculations. Electron transfer from the metal atom to the acetone molecule is found to be more efficient in the Li complex than in the Na complex. This difference is discussed from the atomic and molecular orbital point of view.