Measurement and correlation of the solubilities of 2-[(6-Oxido-6 H -dibenz[ c, e ][1,2]oxaphosphorin-6-yl)methyl]butanedioic acid in selected solvents

The solubilities of 2-[(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl) methyl]butanedioic acid (DDP) in selected solvents were measured by a static analytic method. The measurements were carried out over the temperature range from 293 to 353 K in methanol, ethanol, 1-propanol, tetrahydrofuran, 1,4-dioxane, ethyl acetate, toluene, benzene, and cyclohexane. Several commonly used thermodynamic models, including the empirical equation and the Scatchard-Hildebrand, Wilson, nonrandom two-liquid, and UNIQUAC equations, were applied to correlate the experimental solubility data. The binary interaction parameters of the above models were found to have a linear dependence on the temperature, and the coefficients were regressed. It was found that all of these models can satisfactorily reproduce the experimental data and the UNIQUAC equation can provide the best correlation results with an overall relative standard deviation of 1.52%.