It is shown that high-mobility multimer (CO2)(n)(.-) anions in supercritical (sc)-CO2 form stable complexes with water, aliphatic alcohols, alkyl halides, and alkyl nitriles. The complexation rate is 10-50% of the diffusion controlled rate or faster. The complexes are formed both with the monomer and with the dimer polar solutes. The equilibrium constants of the monomer complexation range from 10 to 350 M-1; the reaction heat is -(15-21) kJ/mol, and the reaction entropy is negative. The stability of the complex increases with the dipole moment of the polar group and decreases with the substitution at the (x-carbon. None of these polar solutes directly reacts with quasifree electrons in sc-CO2.