【作者】 武亚新；

【导师】 聂长明；

【作者基本信息】 南华大学 ， 采矿工程， 2008， 硕士

【摘要】 基于能够合理、有效表征分子结构信息的拓扑指数来进行化合物分子定量结构-性质相关(quantitative structure- property relationships, QSPR),定量结构-活性相关(quantitative structure- activity relationships, QSAR)以及定量结构-谱学性质相关(quantitative structure- spectra relationships, QSSR)研究已经成为一个相当活跃的研究领域,其应用受到了广大化学、生物学、药学等领域科研工作者越来越多的重视。(1)基于离子性指数矩阵、改进的距离矩阵和支化度矩阵建立的新型拓扑指数EDm合理且有效的描述了分子结构信息,并实现了对化合物分子结构的唯一性表征。我们通过新建模型:P=aED1+bED2+cED3+d ( a,b,c,d是常数;P代表化合物分子的性质),研究了EDm指数与部分烷烃、烯烃和炔烃的标准生成焓(△fHm?)、标准熵(Sm?)、摩尔体积(Vm)和摩尔折光度(Rm)等性质之间的关系。模型相关系数介于0.99~1.00。与其他文献报道的拓扑描述符相比,EDm指数具有多项优势,如具有零简并度和更优秀的回归结果等。我们还通过留一法(LOO)和随机抽样法(RSP)对模型进行检验,模型显示出良好稳健性和预测能力。(2)在由离子性指数矩阵、改进的距离矩阵和支化度矩阵建立的EDm指数的基础上,通过在分子隐氢图中引入健角,用两原子间的几何图形距离代替两顶点之间的键长和提出了新型拓扑描述符EDm?。实现了拓扑指数对烯烃顺反异构体结构的有效区分和唯一性表征。通过QSPR模型:P=aED1?+bED2? +cED3?+d ( a,b,c,d是常数;P代表化合物分子的性质),研究了部分烯烃顺反异构体的沸点(b.p.)、标准生成焓(△fHm?)、摩尔体积(Vm)和摩尔折光度(Rm),模型相关系数介于0.984~1.000。检验结果显示模型具有良好稳健性和预测能力。(3)研究发现,R1R2C=O、(RO)2CO、RCO2H、α-卤代乙醛、反式-RONO和R2NNO等系列含X=O键(X=C,N)化合物的红外光谱吸收伸缩振动频率(υ),可以通过由X原子和O原子的离子性指数建立的多元回归模型:P=aINI(O)+b INI(C)+c (a,b,c是常数;P代表化合物分子的性质;INI(O)和INI(X)分别为X原子和O原子的离子性指数)来定量描述。相关系数介于0.960~1.000。同时,我们还用此模型对羰基化合物的紫外光谱吸收能(ΔE)进行QSSR研究。结果表明预测值与实验值十分一致。LOO法检验结果进一步证明了模型良好的稳定性和优良的预测能力。更多还原

【Abstract】 Based on reasonable and available topological index, to study quantitative structure- property relationships (QSPR), quantitative structure- activity relationships (QSAR) and quantitative structure- spectra relationships (QSSR) have played significant roles in chemistry, biology, pharmacology, etc. We should pay more and more attention to the applications of topological index in QSPR/ QSAR study.(1) A novel index EDm based on ionicity index matrix, improved distance matrix and branching degree matrix, is used to describe the structural information of the molecule and realizes unique characterization of the molecular structures. The quantitative structure- property relationship (QSPR) models, with correlation coefficients (R) in the range of 0.99-1.00 for standard enthalpy of formation (△fHm?), standard entropy (Sm?), molar volume (Vm) and molar refraction (Rm) of alkanes, alkenes and alkynes, are subsequently developed using the index EDm. The Leave-one-out (LOO) method and Random sampling prediction (RSP) method demonstrate the models to be statistically significant and reliable. Compared with other published topological descriptors, the index EDm has many advantages such as zero degeneracy, better simulation and so on. Furthermore, the models of solubility and octanol-water partition coefficient are built with satisfied results, which further manifest the superiority and wide application of this index.(2) On the basis of the topological index EDm derived from the ionicity index matrix, the improved distance matrix and the branching degree matrix, we proposed the new topological descriptor EDm? by introducing the bond angle into hidden hydrogen graph of molecules and using the geometric distance instead of the sum of bond length between two vertexes. The EDm? describes the molecular structure more accurately, and realizes unique characterization to cis-trans isomers. The quantitative structure-property relationship (QSPR) models, with correlation coefficients (R) in the range of 0.984-1.000 for the boiling point (b.p.), the standard enthalpy of formation(△fHm?), the molar refraction (Rm) and the molar volume (Vm) of some cis-trans isomers for alkenes, are subsequently developed by index EDm?. Moreover, the good stability and predictive ability of the models were demonstrated by LOO method and RSP method, which further manifests the index EDm? has high potential of wide applications in QSPR study.(3) We find that stretching vibration frequencies of the X=O for series of R1R2C=O, (RO)2CO, RCO2H,α-halogenated aldehydes, cross-RONO and R2NNO can be described by the ionicity indices of X and O atoms as follows:υ= aINI(O)+bINI(X) +c, where a, b, c are regression constants, and INI(X), INI(O) represent the ionicity indices of X and O atoms. The efficiency of the model is verified by high correlation coefficients in the range of 0.960-1.000. Similarly, the ultraviolet absorption energy of ketones can also be characterized by the ionicity indices of C and O asΔE = aINI(O)+bINI(C) +c. The predicted results are in good agreement with the experimental ones. Furthermore, the good stability and powerful predictive ability of those models are proved by LOO method.更多还原