Determination of 1,4-Diethoxybenzene Solubility in 12 Monosolvent Systems at Multiple Temperatures from 278.15 to 318.15 K

1,4-Diethoxybenzene is an important organic synthesis intermediate used in the synthesis of pesticides, pharmaceuticals, fuels, and reagents. In the absence of relevant solubility data for 1,4-diethoxybenzene, it is necessary to study in detail its solubility behavior in various solvents. The solubility data for 1,4-diethoxybenzene in 12 pure solvents, including methanol, ethanol, acetone, 2-butanone, acetonitrile, dimethyl carbonate, ethyl lactate, methyl acetate, ethyl acetate, n-propyl acetate, and isobutyl acetate, was determined. Experiments showed that the solubilities of 1,4-diethoxybenzene molar fractions all increased with increasing temperature. The order of their solubility at 298.15 K is as follows: butyl acetate (0.212 mol/mol) > ethyl acetate (0.179 mol/mol) > 2-butanone (0.169 mol/mol) > n-propyl acetate (0.165 mol/mol) > methyl acetate (0.145 mol/mol) > acetone > isobutyl acetate (0.112 mol/mol) > dimethyl carbonate (0.099 mol/mol) > ethyl lactate (0.074 mol/mol) > acetonitrile (0.067 mol/mol) > ethanol (0.015 mol/mol) > methanol (0.009 mol/mol). Modified Apelblat models, Margules models, UNIQUAC models, and NRTL models were used for correlation of solubility data. The results of ARD and RMSD obtained from the calculations show that each model correlates well with the experimental data. In particular, better solubility correlation results were obtained with the modified Apelblat model. Hirshfeld surface (HS) analysis and molecular electrostatic potential surfaces (MEPS) were utilized to analyze the interactions within 1,4-diethoxybenzene solutions. The Hansen solubility parameters (HSPs) were utilized to assess the solvents' capability and to elucidate its ability to dissolve 1,4-diethoxybenzene. The main factors influencing the solubility behavior include solvent polarity (ET(30)), hydrogen bond, cohesive energy density, and Hansen solubility parameters (HSPs). Furthermore, mixing thermodynamic characteristics of 1,4-diethoxybenzene in selected solvents were calculated by the NRTL model, which revealed that the mixing process was spontaneous and entropy driven. These experimental results can be used for the purification, crystallization, and industrial applications of 1,4-diethoxybenzene as well as similar substances. Therefore, it is necessary to study the solvation behavior of 1,4-diethoxybenzene in different monosolvents to provide sufficient data for the design of its crystallization process.