Solubility Determination and Modeling of 9,9-Dihexyl-2,7-dibromofluorene in Twelve Solvent Systems at 283.15–323.15 K

The 9,9-Dihexyl-2,7-dibromofluorene (F6-Br) is an important intermediate product in the synthesis of functional polyfluorenes for various applications. The solvent/antisolvent method has been one of the efficient methods to purify organic molecules for advanced applications, for which the solubility data of solutes in different solvents are the basis of purification. In this work, the solubility values of F6-Br in 12 kinds of solvents in the temperature range of 283.15-323.15 K and atmospheric pressure were determined by using the isothermal saturation method. The selected solvents were methanol, ethanol, acetonitrile, n-butanol, isopropanol, dichloromethane, dimethyl sulfoxide, 1,4-dioxane, ethyl acetate, n-hexane, tetrahydrofuran, chloroform, and toluene. The measured solubility data were correlated by the modified Apelblat equation. The maximum value of mean square deviation was 3.95 x 10-3, which retains practical guiding significance. The purification of F6-Br via solvent/antisolvent precipitation processing was demonstrated, and the involvement of rotating packed-bed-based technology significantly intensified the process efficiency, which showed promising application value for industrial production.