The Helmholtz free energy of solvation (Delta(slv)A) of 2-propanol and acetone in supercritical CO2 were calculated by expanded-ensemble method. For both solute molecules, Delta(slv)A is well represented by the polynomial equation of the third power of density and the density value correspond to the maximum stability decreases with increasing temperature. In all states under study acetone is more stable than 2-propanol. At low densities the solvation of acetone is more exothermic than 2-propanol while at high densities it come with less entropic penalty. The solvent reorganization energy is more favorable in 2-propanol case, although the role of solute-solvent interactions is dominant in both cases. (c) 2008 Elsevier B.V. All rights reserved.