Solvatochromic shifts of six probe indicators {4-nitroaniline, 4-nitroanisole, 4-nitrophenol, N,N-dimethyl-4-nitroaniline, 4-(2,4,6-triphenylpyridinium)-2,6-diphenylphenoxide and 2,6-dichloro-4-(2,4,6-triphenyl-1-pyridinio)phenolate} have been measured in binary mixtures of carbon dioxide with acetone and methanol at 35 and 40 degrees C over the entire range of solvent composition. The indicators were used to specify the solvatochromic solvent parameters (E-T(30), alpha, beta, and pi*), which were calculated from the solvatochromic shifts of the maximum absorbance peak (v(max)) observed by means of UV-vis spectroscopy. (c) 2005 Elsevier B.V. All rights reserved.