Abstract:

The orientation indices and group corresponding indices of 210 molecular structures of polychlorinated biphenyls（PCBs）and biphenyl were calculatedBy combining these indices with seven thermodynamic properties reported in literature of such PCBs， including standard entropy （S₀），standard enthalpy（H ₀），standard free energy（G₀），total energy（E_T），thermal energy correction（E_th），zeropoint vibration energy（E_zpv）and constant volume molar heat capacity （C⁰_V）， a series of quantitative structure property relationship (QSPR) equations were built up by the multiple regression methodAll the correlation coefficients were larger than 099These models could better explain the change of thermodynamic properties for the PCBs，and the QSPR models had high correlation coefficients，good stability and good predictabilityA modified leaveoneout procedure test was performed to validate model robustness，and predict the S₀，H₀，G₀，E_T，E_th，E_zpv，C_⁰V of other PCBs molecules by the regression equation，and the error analysis were discussedThe results showed better agreement between the values predicted by the model developed and the observed values of the thermodynamic properties.

摘要： 通过计算二噁英类化合物多氯联苯（PCBs）217种分子的定位指数和基团对应指数，以这些分子的热力学性质的文献值为建模样本，运用多元线性回归方法建立了多氯联苯的标准熵（S0）、标准焓（H0）、标准自由能（G0）、分子总能量（ET）、热能校正值（Eth）、零点振动能（Ezpv）及恒容热容（Cv0）等热力学性质的定量结构-性质相关方程，相关系数均在0.99以上。这些模型能较好地解释多氯联苯热力学性质的递变规律，而且相关系数高，稳定性好，预测能力强。采用留一法对模型稳健性进行了检验，得到的预测模型对另外一些多氯联苯分子的热力学性质进行预测，预测结果和文献值基本吻合。