一种修正分子连接性指数杂原子点价的新方法

A Novel Index of Vertex for Hetero - atoms in Molecules

提出了一种对分子连接性指数中杂原子点价进行修正的新方法,新点价统一了碳原子与其它杂原子点价的定义公式,使杂原子的价点价与非价点价的定义具有了唯一性.对原点价的一些不足,尤其是在处理高氧化态原子时得到显著改进,且保持了碳原子与原定义的非价和价点价具有相同的数值,并继承了分子连接性指数原有的好的性质.新点价物理意义明确,具有与原子电负性相近的定义,其价与非价之差与原子的Mulliken电负性有很好的相关性,且在保持了与体积具有良好相关性的基础上,在处理原子的电性性能上有明显改进.进一步明确了价与非价指数的概念,并提出了杂原子取代效应的概念.实际计算应用表明,新点价在处理杂原子,尤其是具有高氧化态和不同氧化态的原子上有明显的改进.

In this paper, we define a novel valence of vertex for hetero - atoms used in molecular topology. The novel valence of vertex can unify the form of vertex valence of various atoms, have explicit physical meanings, and show linear relationship with Mulliken electronegativities. By using the novel index of vertex, different oxidation states for the same atom can be distinguished. We have also generalized the valence and non - valence indexes to hetero - atoms. Results show that this new index keeps all information of the molecular connectivity method but is superior in dealing with the electronic - properties of molecules.