Orenha Renato P, Caramori Giovanni F, Misturini Alechania, Galembeck Sérgio E
Departamento de Química, FFCLRP, Universidade de São Paulo, 14040-901, Ribeirão Preto, SP, Brazil.
Departamento de Química, Universidade Federal de Santa Catarina, Campus Universitário Trindade, CP 476, Florianópolis, Santa Catarina, 88040-900, Brazil.
J Mol Model. 2019 Jan 3;25(1):11. doi: 10.1007/s00894-018-3882-6.
Ruthenophanes have been recognized as potential candidates to the design of electrically conducting polymers, particularly due to their electrochemical, structural, and spectroscopic properties. The comprehension and rationalization of the metal-ligand interaction is fundamental to pave the way for future applications as the design of new conducting materials. For that reason, this investigation sheds light on the electronic details behind the cation-π interactions present in ruthenophanes by using [Ru(η-CH)(NH)] as a model. Zeroth-order symmetry-adapted perturbation theory (SAPT0) shows the interaction Ru(II)-[2.2]paracyclophane with a predominant covalent character. However, the hapticity analysis of [2.2]paracyclophane shows only two predominantly covalent Ru-C bonds, as highlighted by the total energy density, H(r), in the bond critical point (BCP) obtained from quantum theory of atoms in molecules (QTAIM) method, and by second-order stabilization energy, ΔE, related to the processes: π C-C → d or d Ru, achieved in the natural bond orbital (NBO) method. The other two Ru-C chemical bonds show a largely electrostatic character, as can be visualized from the delocalization index, DI, between the electron basins in the electron localization function (ELF) method. Remarkably, the interacting quantum atoms (IQA) method showed practically the same value of the total interaction energy, E[Formula: see text], between Ru and these C atoms and, then, corroborates the hapticity four of the ligand: [2.2]paracyclophane. Source function distribution presents a correlation with the electronic interactions between different groups in [Ru(η-CH)(NH)]. Graphical Abstract The nature of the interactions between [Ru(NH)] and [2.2]paracyclophane in [Ru(η-CH)(NH)] was investigated with different methods of energy decomposition and electron density analysis. This interaction has a predominantly covalent character. It was possible to observe that some Ru-C interactions have a larger covalent character, in contrast for other that are mainly ionic.
钌杂环戊二烯已被公认为是设计导电聚合物的潜在候选物，特别是由于它们的电化学、结构和光谱性质。理解并合理阐释金属-配体相互作用是为未来作为新型导电材料的应用铺平道路的基础。因此，本研究以[Ru(η-CH)(NH)]为模型，揭示了钌杂环戊二烯中存在的阳离子-π相互作用背后的电子细节。零阶对称适配微扰理论（SAPT0）表明Ru(II)与[2.2]对环芳烷的相互作用具有主要的共价特征。然而，[2.2]对环芳烷的配位分析表明，只有两个主要为共价的Ru-C键，这一点在通过分子中的原子量子理论（QTAIM）方法获得的键临界点（BCP）处的总能量密度H(r)以及与π C-C → d或d Ru过程相关的二阶稳定能ΔE中得到了突出体现，这些过程是在自然键轨道（NBO）方法中实现的。另外两个Ru-C化学键表现出很大程度的静电特征，这可以从电子定域函数（ELF）方法中电子盆地之间的离域指数DI看出。值得注意的是，相互作用量子原子（IQA）方法显示Ru与这些C原子之间的总相互作用能E[公式：见原文]实际上具有相同的值，进而证实了配体[2.2]对环芳烷的配位度为4。源函数分布与[Ru(η-CH)(NH)]中不同基团之间的电子相互作用存在相关性。图形摘要 采用不同的能量分解和电子密度分析方法研究了[Ru(η-CH)(NH)]中[Ru(NH)]与[2.2]对环芳烷之间相互作用的性质。这种相互作用主要具有共价特征。可以观察到，一些Ru-C相互作用具有较大的共价特征，而其他一些则主要是离子性的。
