烷烃同系物气相色谱保留指数的分子拓扑研究

Molecular Topological Study on Gas Chromatographic Retention Indices of Alkane Series

定义了分子中原子的平衡电负性,并用原子的平衡电负性对分子图进行着色,在距离矩阵的基础上结合分子中各原子的支化度构建了一种新的拓扑指数N1,N2和N3。该拓扑指数对分子结构实现惟一性表征,具有优良的结构选择性。将拓扑指数N1,N2和N3与烷烃在固定相角鲨烷(柱温50℃)及SE 30(柱温80℃)上的气相色谱保留指数进行多元线性回归,结果表明烷烃的气相色谱保留指数可分别定量描述为I(Squalane)=23 97842N1-3.86562N2+0 787379N3+42 33061,I(SE 30)=23 83937N1-3 5687N2+0 939876N3+22 11952。用上述回归方程对烷烃的气相色谱保留指数进行预测,结果表明预测值与实验值的平均相对误差均为1 31%,预测结果误差在实验误差范围内。

The gas chromatographic retention indices can be used to qualify some organic compounds. A new topological index based on distance matrix and branch vertex of the atoms in a molecule is proposed by defining equilibrium electronegativity of atoms in the molecule and coloring atoms in the molecular graph with equilibrium electronegativity, which appears unique to the molecular structures and has excellent structural selectivity. The multivariate linear equations of gas chromatographic retention indices are as follows:I(Squalane)=23.978 42N_1-3.865 62N_2+0.787 379N_3+42.330 61,R=0.992 2, n=70, S=13.704 05, F=1 396.601;I(SE-30)=23.839 37N_1-3.568 7N_2+0.939 876N_3+22.119 52,R=0.991 9, n=37, S=11.960 88, F=668.878 1;where the N_1, N_2 and N_3 are a group of topological indices; n, R, S and F are sample number, regression coefficient, residual standard deviation and F-statistic value, respectively. The calculated results by the formulae indicate that the average relative deviations between calculated values and experimental data of gas chromatographic retention indices of alkane series on both squalane(column temperature 50 ℃) and SE-30 (column temperature 80 ℃) were all 1.31% and the errors were within experimental deviations. The equations can express well the change rule of the relative gas chromatographic retention indices of alkane series.