Applicability of Hammett parameters (σ_m and σ_p) was tested in extended π-systems in gas phase. Three different model graphene systems, viz. 5,5-graphene (GR), 3-B-5,5-graphene (3BGR), and 3-N-5,5-graphene (3NGR), were designed as extended π-systems, and interactions of various nitrobenzene derivatives (mainly m- and p-substituted together with some multiple substitutions) on such platforms were monitored using density functional theory (M06/cc-pVDZ, M06/cc-pVTZ, M06/sp-aug-cc-pVTZ) and Møller–Plesset second-order perturbation (MP2/cc-pV-DZ) theory. Offset face to face (OSFF) stackings were found to be the favored orientations, and reasonable correlations were found between binding energies (ΔE_B) and the ∑|σ_m| values of the substituted nitrobenzenes. It was proposed previously that |σ_m| contains information about the substituents’ polarizability and controls electrostatic and dispersion interactions. The combination of ∑|σ_m| and molar refractivity (as ∑M_r) or change in polarizability (Δα: with respect to benzene) of nitrobenzene derivatives generated statistically significant correlation with respect to ΔE_B, thereby supporting the hypothesis related to the validity of |σ_m| correlations. The |σ_p| parameters also maintain similar correlations for the various p-substituted nitrobenzene derivatives together with several multiply-substituted nitrobenzene derivatives. The correlation properties in such cases are similar to the |σ_m| cases, and the energy partition analysis for both the situations reveled importance of electrostatic and dispersion contributions in such interactions. The applicability of Hammett parameters was observed previously on the restricted parallel face to face orientation of benzene···substituted benzene systems, and the present results show that such an idea could be used to predict ΔE_B values in OSFF orientations, if the scaffolds are designed in such a way that substituted benzene systems cannot escape their π-clouds.

中文翻译：

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取代的硝基芳烃与石墨烯系统的相互作用：Hammett取代基常数预测结合能的适用性

哈米特参数的适用性（σ_米和σ _p）在气相中的扩展的π系统进行了测试。三种不同的模型石墨烯系统，即。5,5-石墨烯（GR），3-B-5,5-石墨烯（3BGR）和3-N-5,5-石墨烯（3NGR）被设计为扩展π系统，并且各种硝基苯衍生物相互作用（主要是m-和p使用密度泛函理论（M06 / cc-pVDZ，M06 / cc-pVTZ，M06 / sp-aug-cc-pVTZ）和Møller-Plesset二阶摄动（MP2 / cc-pV-DZ）理论。偏移面对面被发现（OSFF）零件组是有利的取向，并且发现结合能（Δ之间的相关性合理È_乙）和Σ|σ_米| 取代硝基苯的值 这是以前提出|σ_米| 包含有关取代基极化性的信息，并控制静电和分散相互作用。Σ的组合|σ_米| 和摩尔折射率（如∑ M _r）或极化（Δα变化：与生成的相对于统计学显著相关以Δ硝基苯衍生物的相对于苯）é_乙，从而支持有关的有效性的假设|σ_米| 相关性。| _σp | 对于各种对位取代的硝基苯衍生物以及几种多取代的硝基苯衍生物，这些参数也保持相似的相关性。在这种情况下，相关特性类似于|σ_米| 两种情况下的能量分配分析，都揭示了静电和分散作用在这种相互作用中的重要性。先前在受限的苯并··取代苯体系的平行面对面取向上观察到Hammett参数的适用性，并且当前结果表明，如果使用支架，则这种思想可用于预测OSFF取向中的ΔE _B值。以取代苯系统无法逃脱其π云的方式进行设计。