A combined photoelectron spectroscopy and ab initio theoretical study was carried out to
study the microsolvation of the acetate anion. Photoelectron spectra of cold solvated clusters
CH3CO2.(H2O)n (n = 1.3) at 12 K were obtained and compared with theoretical calculations.
The first water is shown to bind to the .CO2. group in a bidentate fashion, whereas both waterwater
and water-CO2. interactions are shown for n = 2 and 3. Significant rearrangement of the
solvation structures is observed upon electron detachment, and water-CH3 interactions are
present for all the neutral clusters, CH3CO2(H2O)n (n = 1.3).