Solubility Measurement and Model Correlation of N,N′-Oxalyldiglycine in Eleven Pure Solvents and a Binary Solvent from 293.15 to 333.15 K

The solubility of N,N'-oxalyldiglycine (OG) in 11 pure solvents, including methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, acetonitrile, ethyl acetate, tetrahydrofuran (THF), water, N,N'-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO), and a binary solvent system composed of DMSO and water was measured by a dynamic laser monitoring method with the temperature ranging from 293.15 to 333.15 K. Results of these experiments demonstrated that the solubility of OG in all pure solvents increases with rising temperature. The highest solubility appeared in DMSO while the lowest solubility appeared in ethyl acetate. Besides, the mole fraction solubility of OG in binary solvents increases with increasing content of DMSO. Furthermore, the experimental solubility of OG in pure solvents was correlated with the modified Apelblat, Van't Hoff, lambda h, and Wilson models. Four models (Van't Hoff, CNIBS/R-K, modified Jouyban-Acree, and Wilson) were used for the binary solvents. The Van't Hoff model best correlates with the experimental values in pure and binary solvents, and the calculated values by the Wilson model have a large deviation from the experimental values.