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在矩和分子片断计数基础上,将Hückel总能量向矩和分子片断展开。利用已知分子的E_π计算值,在最小二乘方意义下确定展开式的系数,使分子总能量具有片断加和性意义。结果表明,各种片断能量贡献绝对值随片断增大而减小,正负号交替变化:即偶片断起稳定作用,奇片断起活化作用,称之为广义Hückel规则。以此为基础,讨论了芳香性问题,规定了参考结构条件,统一了REPE和TRE两种芳香性判据的分歧。同时也指出了REPE方案中参数化的不唯一性,讨论了它们之间的关系。
Based on moments and molecular fragment counts, the total energy of Hückel is expanded to moments and molecular fragments. Using the calculated values of E_π of known molecules, the expansion coefficient is determined in the least square sense, making the total energy of the molecules have the significance of fragment summation. The results show that the absolute value of energy contributions of various segments decreases with the increase of segments, and the sign changes alternately: that is, the plateau is stable and the activation of odd slices is called the generalized Hückel rule. Based on this, the problem of aromaticity was discussed, the reference structural conditions were defined, and the differences between the two aromaticity criteria of REPE and TRE were unified. At the same time, it also points out the non-uniqueness of parameterization in REPE scheme and discusses the relationship between them.