用碳链准长度估算多环芳烃的分配系数

Estimation of partition coefficient for the multiring hydrocarbon using the quasi length of carbon chain

根据极化效应指数理论计算出多环芳烃的分子极化指数和碳链准长度（Ｎ＇），研究发现，碳链准长度Ｎ’与多环芳烃在正辛醇／水两相的分配系数ｌｏｇＫｏｗ有良好的线性关系，它可表示为ｌｏｇＫｏｗ＝０．５４４１＋０．３７６７Ｎ’ｎ＝３２Ｒ＝０．９８０４ｓ＝０．２２１４。用Ｎ’估算和预测多环芳烃的分配系数ｌｏｇＫｏｗ与测定值和Ｌｅｏ碎片法估算值一致，并且准碳链长度Ｎ’可直接从分子结构计算得到，经验成分较少，也不需要引入其它结构校正因子。

The molecular polarizability index and quasi length of carbon chain have been calculated for the multiring hydrocarbon basing on the polirizability effect indes (PEI)theory.It was discovered that there was a good lineality relation between quasi length of carbon chain (N′) and the logarithm of partition coefficient in n octyl alcohol and water (log Kow) for the multiring hydrocarbon and the relationship can be expressed as follows:logKow=0.5441+0.3767N′ n=32 R=0.9804 s=0.2214.The logKow values estimated and predicted by the expression a good agreement with the values measured and estimated by Leo′s method more over the quasi length of carbon chain (N′) can be calculated directly from the molecular structure and it does not require any correct factor of molecular structure for the calculation of N′.