无机含氧酸结构与其强度定量关系研究

A quantitative relationship study between the structure and intensity of the inorganic oxyacid

应用物质结构-性质关系(QSPR)方法研究25种无机含氧酸pK_1与分子描述符之间的定量关系。采用DRAGON5.4软件和HyerChem7.5计算了25种无机含氧酸分子的426种结构类参数和12种量子化学参数。根据偏差权重法筛选出39种结构描述符。采用多元逐步回归分析建立了25种无机含氧酸结构-性质关系,得到最佳方程:pK_1=13.421-4.937X1AV+0.508PCW+1.015S-0.100LUMO+0.398P-3.94~*10^(-7)Et。方程相关系数R为0.995,标准偏差S为0.577。且有F>Fα,表明方程回归效果显著;对回归系数的t检验结果均有Sig<0.05,表明6个参数对pK_1影响显著。"逐一剔除"交叉验证的结果证明模型具有良好的稳定性和较强的预测能力。6个参数物理意义及其对pK_1影响的深入分析表明,其中的S(3Se+Sp-1.75Ss),X1AV(average valence connectivity index chi-1)和PCWte(partial charge weighted topological electronic descriptor)3个参数是影响酸无机含氧强度的关键结构参数。

quantitative structure-property relationship（QSPR）method was performed to study the relationship between pK_1 values and molecular descriptors of 25 sorts of inorganic oxyacids.With the DRAGON5.4（2006） software and HyerChem7.5,426 structural parameters and 12 quantum chemistry parameters for 25 sorts of inorganic oxyacids are calculated.39 structural descriptors are chosen by using the variable selection method of weighted deviation.The QSPAR of 25 sorts of inorganic oxyacids is set up with stepwise regress pK_1=13.421 - 4.937X1AV ＋ 0.508PCW ＋1.015S-0.100LUMO ＋ 0.398P - 3.94＊10^（-7）Et.The equation has the correlation coefficient R of 0.995 and the standard derivations 5 of 0.577.Furthermore,the two-sided t-test was used to validate the significance of the 6 descriptors.The statistically significant（0.05）correlation coefficients of descriptors show that the 6 descriptors have important impacton the pK_1 values. Furthermore,leave-one-out cross validation as perfonned,which confirmed the good stability and powerful prediction of this model.The physical meaning and the influence of the six prameters on pK_1 of inorganic oxyacids were investigated.The three parameters, S（3Se＋Sp-1.75Ss）,X1AV（average valence connectivity index chi-1） and PCWte（partial charge weighted topological electronic descriptor） are the key factors affecting the acid intensity of inorganic oxyacids.