无机含氧酸pK_1的定量构效关系(QSPR)研究  

Prediction of acidity constants of inorganic oxyacids using a QSPR based on the ab initio method

作　　者：李莉[1] 张运陶[1] 

机构地区：[1]西华师范大学应用化学研究所,四川南充637002

出　　处：《计算机与应用化学》2010年第12期1711-1714,共4页Computers and Applied Chemistry

基　　金：NSFC(10802081)

摘　　要：采用Tomasi的极化统一模型对20种无机含氧酸HnROm在水相条件下进行从头算,选取14个量化参数结合含氧酸非羟基氧原子数等2个重要结构参数对含氧酸pK1进行逐步回归,引入非羟基氧原子数NO、非羟基氧原子净电荷数NCO、羟基氢原子净电荷数NCH(O)和氢氧间的重叠布居数POPR-O(H)4个参数建立QSPR方程,方程相关系数R为0.9946,且有F>Fα,表明方程回归效果显著;对回归系数的双边t检验结果均有P<0.05,表明此4个参数对pK1影响显著。对引入参数的物理意义及其对含氧酸pK1的影响分析表明,此4个参数均与羟基氧原子电子密度相关;其中NCH(O)和NO是影响含氧酸强度的主要因素,且NCH(O)的影响更大;NCO和POPR-O(H)则是影响含氧酸强度的次要因素,可用于区分各含氧酸强度的细微差别。此外,将NCH(O)、POPR-O(H)用于对35种酸碱进行分类也获得了良好的分类效果,表明此2个参数可用于区分R-O-H的电离方式。A descriptive and interpretable model,based on a quantitative structure-property relationship（QSPR）,is developed using stepwise regression approach and quantum chemical descriptors derived from ab initio methods for some inorganic oxyacids（HnROm）.By molecular modeling and calculation of descriptors,the number of the oxygen atom in non-hydroxyl（NO）,net charge of the oxygen atom in non-hydroxyl（NCO）,net charge of the hydrogen atom in hydroxyl（NCH（O））,and overlap population between center atom R and hydroxyl oxygen atom（POPR-O（H））,were picked out to constitute the equation of QSPR.The equation has the correlation coefficient R of 0.994 7 and the standard derivation s of 0.580 4.Furthermore,the two-sided t-test was used to validate the significance of the 4 descriptors.The statistically significant（P0.05） correlation coefficients of descriptors show that the 4 descriptors have important impact on the pK1 values.The studies of the 4 descriptors with pK1 values of inorganic oxyacids indicate that the 4 descriptors are related to the electronic density of oxygen atom in hydroxyl;NO and NCH（O） are the main factors which affect the acidity strength of inorganic oxyacids,NCO and POPR-O（H） have the less effect,but they can distinguish the nuance of acidity strength between the inorganic oxyacids.In addition,NCO and POPR-O（H） can efficiently classify the 35 acids and alkali,which indicate that they can distinguish the mode of ionization of R-O-H.

关 键 词：无机含氧酸 pK1 极化统一模型 从头计算 电子密度 定量结构性质关系 

分 类 号：O63[理学—高分子化学]