Department of Chemistry, Wayne State University, Detroit, MI 48202, USA.
J Chromatogr A. 2023 Sep 27;1707:464296. doi: 10.1016/j.chroma.2023.464296. Epub 2023 Aug 13.
Revised descriptors are determined for fifteen phthalate esters for use in the solvation parameter model and form part of the Wayne State University (WSU) compound descriptor database. For thirteen phthalate esters a comparison is made with the same compounds in the Abraham descriptor database. Gas chromatographic retention factors on poly(methyloctylsiloxane), SPB-Octyl, and poly(cyanopropylphenyldimethylsiloxane), DB-225, stationary phases are used to facilitate an assessment of the contribution of cavity formation and dispersion interactions, L descriptor, and dipole-type interactions, S descriptor, to the experimental retention factors (log k) for the phthalate esters with minimum interference from competing intermolecular interactions. The results indicate a systematic overprediction of the cavity and dispersion interaction term and underprediction of dipole-type interactions for the Abraham descriptors compared with the WSU descriptors for the phthalate esters. The average absolute deviation (AAD) for 13 phthalate esters on SPB-Octyl is 0.039 (WSU descriptors) compared with 0.252 (Abraham descriptors) and for 9 phthalate esters on DB-225 0.030 (WSU descriptors) compared with 0.167 (Abraham descriptors). The results for dipole-type interactions are confirmed and extended to include the hydrogen-bond basicity of the phthalate esters, B descriptor, by evaluation of partition constants in aqueous biphasic systems and the n-heptane-2,2,2-trifluoroethanol biphasic system. Differences in the contribution of the hydrogen-bond basicity of the phthalate esters to the experimental partition constants are largely random with respect to database selection but important for the accurate prediction of the partition constants. The AAD for the partition constant for 15 phthalate esters is 0.063 (WSU descriptors) compared with 0.320 (Abraham descriptors) for the heptane-2,2,2-trifluoroethanol biphasic system and 0.13 (WSU descriptors) compared with 0.25 (Abraham descriptors) for 9 phthalate esters in the octanol-water biphasic system. The WSU descriptors for the phthalate esters exhibit a better fit with the experimental data for separation systems and are free of the extreme values predicted for the Abraham descriptors for several phthalate esters.
修订后的描述符用于十五种邻苯二甲酸酯，用于溶剂化参数模型，并构成韦恩州立大学 (WSU) 化合物描述符数据库的一部分。对于十三种邻苯二甲酸酯，与亚伯拉罕描述符数据库中的相同化合物进行了比较。使用聚甲基辛基硅氧烷 (SPB-Octyl) 和聚氰丙基苯基二甲基硅氧烷 (DB-225) 固定相上的气相色谱保留因子来评估空腔形成和色散相互作用、L 描述符以及偶极型相互作用、S 描述符对实验保留因子 (log k) 的贡献邻苯二甲酸酯的实验数据最小化了来自竞争的分子间相互作用的干扰。结果表明，与 WSU 描述符相比，亚伯拉罕描述符系统地高估了空腔和色散相互作用项，低估了偶极型相互作用项。SPB-Octyl 上 13 种邻苯二甲酸酯的平均绝对偏差 (AAD) 为 0.039(WSU 描述符)，而 0.252(亚伯拉罕描述符)，DB-225 上 9 种邻苯二甲酸酯的 AAD 为 0.030(WSU 描述符)，而 0.167(亚伯拉罕描述符)。偶极型相互作用的结果得到了证实，并通过评估水相两相系统和正庚烷-2,2,2-三氟乙醇两相系统中的分配常数，将其扩展到邻苯二甲酸酯的氢键碱性，B 描述符。邻苯二甲酸酯氢键碱性对实验分配常数的贡献的差异在很大程度上是随机的，与数据库选择有关，但对准确预测分配常数很重要。15 种邻苯二甲酸酯的分配常数的 AAD 为 0.063(WSU 描述符)，而正庚烷-2,2,2-三氟乙醇两相系统的 0.320(亚伯拉罕描述符)，9 种邻苯二甲酸酯的 AAD 为 0.13(WSU 描述符)，而正辛醇-水两相系统的 0.25(亚伯拉罕描述符)。邻苯二甲酸酯的 WSU 描述符与分离系统的实验数据拟合更好，并且没有亚伯拉罕描述符为几种邻苯二甲酸酯预测的极端值。
