用分子拓扑指数研究烷烃的物化性质-连接性指数

用分子拓扑指数研究烷烃的物化性质_连接性指数论文内容摘要：本文通过计算44种烷烃的连接性指数，用多元线性回归分别将它与毛细管气相色谱保留指数、生成热进行关联分析获得良好的相关性，相关系数R为0.992与0.998，所建立的回归模型具有良好的稳定性与预测能力。论文本文关键词语：连接性指数,保留指数,烷烃,生成热定量构造—性质/活性相关性(QSPR/QSAR)研究，以其简单、快速、精确等特点，引起广阔化学工作者的普遍关注。其中化合物的拓扑构造研究，即拓扑指数法应用很广。分子拓扑学是图论,构造化学,计算机科学及统计学穿插的一门新兴学科,它把数学上图的拓扑性质与化学的分子构造图对应起来,目的是寻找分子构造图的拓扑不变量,将一个抽象的化学构造图转化为数学上的一个没有量纲的数,进而实现分子构造的拓扑指数表示，用于建立化合物与性能的定量关系。本文通过价连接性指数、、碳原子数C以及临界体积V等关联色谱保留指数ω、生成热H性质，建立了定量构造—性质相关模型，预测结果满意。1价连接性指数的构建。本文以Randi支化度指数为基础,定义分子的连接性指数为,以下图为2,2—二甲基丁烷分子的构造点价图。现以2,2—二甲基丁烷为例计算其分子的连接性指数：=4×(1)＋1×(4)＋1×(2)=5.2071=3×(1×4)＋1×(2×4)＋1×(1×2)=2.5607分别计算各烷烃的,值,列于表1.2结果与讨论2.1数据的来源饱和烷烃的生成热H,临界体积V均由ChemDrawUltra8.0软件计算得到。保留指数ω取自文献[2],这些数据是在长50m,内径0.21m,涂有0.50m厚的HPPONA毛细管柱上于60℃时测得的。2.2价连接性指数与烷烃性质的相关性。2.2.1烷烃的色谱保留指数ω与、、C的定量关系。ω=88.574-64.012+78.028+99.418C(R=0.992,R=0.984,F=805.093,n=44)2.2.2烷烃的生成热H与、C、V之间的定量关系。H=8.062-38.249+57.983C-0.928V(R=0.998,R=0.996,F=552.270,n=44)表1烷烃的色谱保留指数ω、生成热H、临界体积V、拓扑指数、化合物CωH〔KJ/mol〕V(㎝/mol)2,2-dimethylbutane6538.0-175.92360.55.20712.5607cyclopentane5567.3-65.71257.53.53552.50002-methylpentane6569.8-172.45365.54.99162.77002,2-dimethylpentane7625.7-196.56416.55.91423.0607methylcyclopentane6630.4-106.69312.54.40582.89393,3-dimethylpentane7658.1-196.56416.55.91423.12122-methylhexane7667.8-193.09421.55.69872.69272,3-dimethylpentane7671.1-198.37415.55.28453.18071,1-dimethylcyclopentane7675.9-112.09366.55.32843.20713-methylhexane7676.8-193.09421.55.69873.30813-ethylpentane7687.0-193.09421.55.69873.3460methylcyclohexane7724.0-133.49360.55.11293.39392,2-dimethylhexane8722.9-217.20472.56.62133.5607ethylcyclopentane7734.3-127.33368.55.11293.43183,3-dimethylhexane8742.9-217.20472.56.62133.62132,3,4-trimethylpentane8751.9-224.29465.56.73213.55352,3-dimethylhexane8761.4-219.01471.56.56893.68073-ethyl-2-methylpentane8763.2-219.01471.56.56893.71862-methylheptane8766.5-213.73477.56.40583.77004-methylheptane8768.1-213.73477.56.40583.80803-methylheptane8774.2-213.73477.56.40583.56392,2,5-trimethylhexane9785.1-243.12522.57.49163.91651-ethyl-1-methylcyclopentane8794.3-132.73422.56.03553.76782,3,5-trimethylhexane9817.0-244.93521.57.43924.03662,6-dimethylheptane9830.3-239.65527.57.2764.12591,1,3-trimethylcyclohexane9836.5-179.87469.56.90584.10102,3,3-trimethylhexane9838.9-243.12522.57.49164.00413,5-dimethylheptane9837.4-239.65527.57.27604.20193,4-dimethylheptane9859.2-239.65527.57.27604.21874-methyloctane9864.6-234.37533.57.11294.30813-ethylheptane9871.1-234.37533.57.11294.34603,3-diethylpentane9875.3-237.84528.57.32844.24262,6-dimethyloctane10934.9-260.29583.57.98314.66395-methylnonane10960.8-255.01589.57.82004.80812,3-dimethylbutane6567.3-177.73359.55.15472.64272,4-dimethylpentane2,5-dimethylhexane78631.0732.5-198.37-219.01415.5471.55.86186.56893.12593.62592,4,4-trimethylhexane3,3-dimethylheptane99808.7839.1-243.12-237.84522.5528.57.49167.32843.97714.12134-ethylheptane9861.8-234.37533.57.11294.34603-methyloctane9872.2-234.37533.57.11294.30813,5-dimeth