Metal-Organic Frameworks (MOFs) are an interesting class of hybrid organic-inorganic materials with potential applications in different areas of science and technology. In the present study, we explored different two-dimensional conjugated MOFs (2D c-MOFs) constructed through the coordination of hexahydroxyarylene-ethynylene (HHAE) or hexahydroxyarylene-butadiynylene (HHAB) ligands with M²⁺ (M=Co, Ni, Cu, and Zn) ions using density functional theory studies. All the 2D c-MOF structures were optimized, and their electronic band structures and the projected density of states were calculated to understand their electronic structure. The electronic band structure of Cu-based c-MOFs indicates the presence of half-filled flat bands of the kagome lattice around the Fermi level and is found to be ferromagnetic in nature. Along with the single-layer 2D MOFs, the multilayer stacked system was also studied to understand the interlayer interactions, and the results were consistent with the reported experimental results. Adsorption of small molecules, CO₂, H₂O, O₂, and N₂, over the Cu c-MOF was studied to understand the reactivity of these MOFs. From the calculated interaction energies, these MOFs were found to have two different active adsorption sites, the metal site and the annulene ring site, depending on the adsorbing molecule.

Graphical abstract

Electronics structure and reactivity of two-dimensional conjugated metal-organic frameworks (2D c-MOFs) constructed through the coordination of hexahydroxyarylene-ethynylene (HHAE) or hexahydroxyarylene-butadiynylene (HHAB) ligands with the M²⁺ (M=Co, Ni, Cu, and Zn) ions were studied using density functional theory calculation.

中文翻译：

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结合二维金属有机骨架的脱氢苯并 [n] 环烯的电子结构和反应性

金属-有机骨架 (MOF) 是一类有趣的有机-无机杂化材料，在不同的科学和技术领域具有潜在的应用前景。在本研究中，我们探索了通过六羟基亚芳基-亚乙炔基 (HHAE) 或六羟基亚芳基-丁二炔基 (HHAB) 配体与 M 2+ 配位而构建的不同二维共轭 MOF (2D c-MOF ⁾使用密度泛函理论研究的（M=Co、Ni、Cu 和 Zn）离子。所有二维 c-MOF 结构都经过优化，并计算了它们的电子能带结构和投影态密度，以了解它们的电子结构。Cu 基 c-MOF 的电子能带结构表明在费米能级周围存在 kagome 晶格的半满平带，并且被发现在本质上是铁磁性的。除了单层 2D MOF，还研究了多层堆叠系统以了解层间相互作用，结果与报道的实验结果一致。小分子、CO ₂、H ₂ O、O ₂和N _2的吸附，研究了 Cu c-MOF 以了解这些 MOF 的反应性。根据计算的相互作用能，发现这些 MOF 具有两个不同的活性吸附位点，即金属位点和轮烯环位点，具体取决于吸附分子。

图形概要

通过六羟基亚芳基-亚乙炔基 (HHAE) 或六羟基亚芳基-丁二炔基 (HHAB) 配体与 M 2+ (M=Co, ^Ni ,使用密度泛函理论计算研究了 Cu 和 Zn) 离子。