The IEFPCM/MST continuum solvation model is used for the blind prediction of n-octanol/water partition of a set of 11 fragment-like small molecules within the SAMPL6 Part II Partition Coefficient Challenge. The partition coefficient of the neutral species (log P) was determined using an extended parametrization of the B3LYP/6-31G(d) version of the Miertus–Scrocco–Tomasi continuum solvation model in n-octanol. Comparison with the experimental data provided for partition coefficients yielded a root-mean square error (rmse) of 0.78 (log P units), which agrees with the accuracy reported for our method (rmse = 0.80) for nitrogen-containing heterocyclic compounds. Out of the 91 sets of log P values submitted by the participants, our submission is within those with an rmse < 1 and among the four best ranked physical methods. The largest errors involve three compounds: two with the largest positive deviations (SM13 and SM08), and one with the largest negative deviations (SM15). Here we report the potentiometric determination of the log P for SM13, leading to a value of 3.62 ± 0.02, which is in better agreement with most empirical predictions than the experimental value reported in SAMPL6. In addition, further inclusion of several conformations for SM08 significantly improved our results. Inclusion of these refinements led to an overall error of 0.51 (log P units), which supports the reliability of the IEFPCM/MST model for predicting the partitioning of neutral compounds.

IEFPCM / MST连续溶剂化模型用于对SAMPL6 Part II分配系数挑战中一组11个片段状小分子的正辛醇/水分配进行盲预测。使用在正辛醇中的Miertus-Scrocco-Tomasi连续介质溶剂化模型的B3LYP / 6-31G（d）版本的扩展参数化，确定中性物质的分配系数（log P）。与为分配系数提供的实验数据进行比较，得出的均方根误差（rmse）为0.78（log P单位），这与我们针对含氮杂环化合物的方法报道的准确性（rmse = 0.80）相吻合。在91套日志P中参与者提交的值，我们的提交均在均方根<1的那些值之内，并且是四种排名最高的物理方法之一。最大的误差涉及三种化合物：两种具有最大的正偏差（SM13和SM08），以及一种具有最大的负偏差（SM15）。在这里，我们报告了SM13的log P的电位测定，得出的值是3.62±0.02，与大多数经验预测相比，该值与SAMPL6中报告的实验值更好地吻合。此外，进一步包含SM08的几种构象可显着改善我们的结果。包括这些改进导致总误差为0.51（log P单位），这支持了IEFPCM / MST模型用于预测中性化合物分配的可靠性。