Determination and Correlation of Solubility of 2,4,6,8,10,12-Hexacyclopropyl-2,4,6,8,10,12-hexaazaisowurtzitane in 12 Pure Solvents at Temperatures Ranging from 278.15K to 318.15K

2,4,6,8,10,12-Hexacyclopropyl-2,4,6,8,10,12-hexaazaisowurtzitane (HCPIW) is a novel nitration precursor used in the synthesis of CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane). Investigating the solubility of HCPIW is of significant importance for optimizing its synthesis and crystallization processes, as well as for advancing the development of the CL-20 synthetic route. However, to the best of our knowledge, no studies have been reported on the solubility of HCPIW. To support downstream processing, its solubility in 12 pure solvents (dichloromethane, chloroform, carbon tetrachloride, 1,1,2-trichloroethane, 1,2-dichloroethane, n-hexane, cyclohexane, ethyl acetate, acetone, methanol, ethanol, and acetonitrile) was determined by the gravimetric method over the temperature range of 278.15 to 318.15 K. The experimental solubility data were correlated using the Apelblat equation, Yaws model, van’t Hoff equation, and a polynomial empirical model. All four models exhibited excellent agreement with the experimental data, with correlation coefficients (R²) exceeding 0.99 and root-mean-square deviations (RMSD) approaching zero. These models are thus suitable for accurately describing the solubility behavior of HCPIW. This study provides essential thermodynamic data to support further research and process development involving HCPIW.