Photoelectron images of [(CH3)(2)CO](n)(-) (n = 2, 5-15) were recorded at 3.49 eV. Analysis of the images provided the vertical detachment energies (VDEs) and photoelectron angular distributions (PADS) of [(CH3)(2)CO](n)(-). The n-dependence of these quantities starts with VDE = 0.83 +/- 0.03 eV and beta approximate to -0.3 at n = 2, and it ends up with 2.83 +/- 0.03 eV and approximate to 0.1 at n = 15. These findings, in conjunction with ab initio results, indicate: (1) the formation of a specific anion structure at n = 2; and (2) the presence of a solvent-stabilized (CH3)(2)CO(-)valence anion in the larger analogues. (c) 2006 Elsevier B.V. All rights reserved: