用DFT-B3LYP方法,在较高基组6-311G**水平上对28种取代苯甲醛类化合物进行全优化计算获得了相应量子化学参数,利用线性逐步回归法建立取代苯甲醛溶解度的定量结构-活性相关性(QSPR)模型.采用内部及外部双重验证的办法深入分析和检验模型的稳健性,选出了最佳模型,其复相关系数(R2),留一法(LOO)交互检验复相关系数(Rc2v),外部预测样本复相关系数(Re2xt)分别为0.935,0.933和0.842,表明所建立的QSPR模型的稳定性和预测能力良好.结果表明:取代苯甲醛的溶解度lgSW与分子总能量,分子体积,分子最低空轨道能和最负原子的静电荷相关性较好.
The DFT-B3LYP method,with the basis set 6-311G**,was employed to calculate the molecular geometries and electronic structures of 28 substituted benzaldehydes.Here the quantitative structure-property relationship(QSPR) model was built by multiple linear stepwise regressions(LSR).The estimation stability and the generalization ability of the model was strictly analyzed by both internal and external validation and the best one was selected.The correlation coefficient(R2),leave-one-out(LOO) cross validation(R2cv),and predicted values versus experimental ones of external samples(R2ext) of established LSR model are 0.935,0.933 and 0.842,respectively.These show that the QSPR model has both favorable estimation stability and good prediction capability.The results indicate that there is a good multivariate linear relationship between the aqueous solubility(lgSW) of substituted benzaldehydes and the total energy of the molecular,molecular volume,energy of the lowest unoccupied molecular orbital,and the lowest negative charge.