Abstract Graph theory based method is proposed for constructing a complete set of homodesmotic reactions (HDR) for studying the molecular energy of organic compounds. The efficiency of the method is shown by the example of ring strain energy Es calculation for a test set of 65 cyclic compounds. The absolute enthalpies of the cycles as well as of reference compounds used in HDRs were calculated using the composite methods G3 and G4. Depending on the structure of the studied cyclic compound, the thermal effect of HDR was shown to be a combination of uncompensated non-valence effects: ring strain, gauche interaction, hydrogen bonding, as well as difference in far environment of atoms, which is observed as the effect of small molecules. Within the framework of a complete set of HDRs, it is possible to separate all of these effects and determine Es free from secondary interactions. The obtained Es set allows tracing its relation with different structural factors such as cycle size, presence of hetero- or sp2-hybridized atoms in the cycle, effect of the substituent etc.

中文翻译：

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用于分析三至六元环状有机化合物非价效应的全套同质反应

摘要 提出了基于图论的方法来构建一套完整的同向反应（HDR），用于研究有机化合物的分子能量。该方法的效率通过对 65 种环状化合物的测试集计算环应变能 Es 的示例显示。循环的绝对焓以及 HDR 中使用的参考化合物的绝对焓使用复合方法 G3 和 G4 计算。根据所研究的环状化合物的结构，HDR 的热效应被证明是未补偿的非价效应的组合：环应变、gauche 相互作用、氢键，以及观察到的原子远环境差异作为小分子的作用。在一套完整的HDRs框架内，可以将所有这些影响分开并确定没有二次相互作用的 Es。获得的 Es 集可以追踪其与不同结构因素的关系，例如环大小、环中杂杂或 sp2 杂化原子的存在、取代基的影响等。