Quantum mechanical predictions of the Henry's law constants and their temperature dependence for the 209 polychlorinated biphenyl congeners.
Quantum mechanical predictions of the Henry's law constants and their temperature dependence for the 209 polychlorinated biphenyl congeners.
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209 种多氯联苯同系物的亨利定律常数及其温度依赖性的量子力学预测。
DOI：
10.1021/es800876w
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发表时间：
2008
影响因子：
11.4
通讯作者：
DiToro,DominicM
中科院分区：
文献类型：
--
作者：
Phillips,KathyL;Sandler,StanleyI;Greene,RichardW;DiToro,DominicM
用量子力学(QM)连续溶剂化模型COSMO-SAC和SM6预测了所有209种多氯联苯(PCBs)同系物在25℃时的亨利定律常数(HLC)，并考察了它们的变化趋势。还预测了4、11、18和31°C时所有同系物的Cosmo-SAC HLC。HLC的温度依赖关系被用来计算溶剂化热(ΔHS)值。在25摄氏度时，Cosmo-SAC和SM6预测的HLC值相似，除了一组可用测量外，其他所有测量值都是一致的，并且预测均方根误差比测试的其他模型小。这支持了QM值的有效性，以及在环境运输和命运模型中使用它们的建议。多氯联苯-水极性相互作用的强度似乎主导着高氯烃的类间趋势。COSMO-SAC在4℃到31℃之间的预测表明，HLC的温度依赖关系对于所有同系物来说都是相似的。在低温下，HLC对几个重同系物的预测大大高于最近报道的测量结果，支持了文献中关于这些低温数据不准确的说法。
The Henry’s law constants (HLCs) for all 209 polychlorinated biphenyl (PCB) congeners were predicted at 25 °C using the quantum mechanical (QM) continuum solvation models COSMO-SAC and SM6, and trends were examined. COSMO-SAC HLCs were also predicted for all congeners at 4, 11, 18, and 31 °C. The temperature dependences of the HLCs were used to calculate enthalpy of solvation (ΔHS) values. At 25 °C, COSMO-SAC and SM6 predicted similar values of the HLC, which are consistent with all but one of the available sets of measurements, and have smaller root-mean-square prediction errors than other models tested. This supports the validity of the QM values, and the recommendation of their use in environmental transport and fate models. Intercongener trends in the HLCs appear to be dominated by the strength of PCB-water polar interactions. The COSMO-SAC predictions between 4 and 31 °C indicate that the temperature dependence of the HLC is similar for all congeners. At low temperatures, the HLC predictions for several heavy congeners are substantially higher than recently reported measurements, supporting claims in the literature that these low-temperature data are inaccurate.