Solubility data were obtained for the first time for phenylboric acid, iodobenzene, and biphenyl in carbon dioxide at (353 and 383) K and between pressures of (100 to 300) bar. Data were obtained using a method that used the relative permittivity of the binary mixture. The technique was verified by comparison of solubility data for 4-phenyltoluene that had been determined previously by ourselves using a cloud point technique. The relative permittivity for CO2 was also determined at (353 and 383) K between pressures of (100 to 300) bar.