多溴代二苯并呋喃/噻吩热力学性质的定量构效关系

多溴代二苯并呋喃(PBDFs)是剧毒环境污染物,主要来源于溴系阻燃剂的燃烧和高温裂解过程,其性质与其结构有关;多溴代二苯并噻吩(PBDTs)的结构与其非常相似。通过计算多溴代二苯并呋喃和多溴代二苯并噻吩254个分子的原子特征值,利用分子图形学技术获得了一种新的连接性指数——路径指数mP,采用多元回归分析方法建立了PBDFs的分子总能量(ET)、标准焓(H0)、自由能(G0)、标准熵(S0)和恒容热容(c0v)以及PB-DTs的标准焓(H0)、自由能(G0)、标准生成焓(ΔfH0)和标准生成吉布斯自由能(ΔfG0)的定量结构-性质相关模型,相关性良好(r20.995),利用Jackknifed法检验了模型的稳定性和预测能力,Jackknifed检验的相关系数r2均在0.995以上,对标准熵预测的相对平均误差为0.52%,预测结果和文献值基本吻合。

QSPR study on thermodynamic properties of polybrominated dibenzofurans and polybrominated dibenzothiophenes

Polybrominated dibenzofurans (PBDFs)are important toxic organic contaminants released from the combustion and Pintsch process of brominated flame retardants.The properties of PBDFs are related to their structures.The structure of polybrominated dibenzothiophenes (PBDTs)is similar to that of PBDFs.In this study, atomic characteristic values of 254 molecular structural patterns of PBDEs and PBDTs are calculated, and a new connectivity index, the path index, is obtained by applying the technique of molecule graphics.The path index is combined with five thermodynamic properties of PBDFs, including molecular total energy (E_T), standard enthalpy (H⁰), free energy (G⁰), standard entropy (S⁰)and heat capacity at constant volume (c⁰_v), along with four thermodynamic properties of PBDTs, including standard enthalpy (H⁰), free energy (G⁰), standard enthalpy of formation (Δ_fH⁰)and standard free energy of formation (Δ_fG⁰）.Nine quantitative structure-property relationship models (r²>0.995)are obtained by multiple linear regression method.The Jackknifed cross validation is used to test the stability and prediction ability of each model and good results (r²>0.995)are obtained.The relative mean deviation is 0.52% to S0.The model developed is in good agreement with the values of S⁰ in literature.