Potential applications of 2D metal–organic frameworks (MOF) require the frameworks to be monophase and well-defined at the atomic scale, to be decoupled from the supporting substrate, and to remain stable at the application conditions. Here, we present three systems meeting this elusive set of requirements: M-TCNQ (M = Ni, Fe, Mn) on epitaxial graphene/Ir(111). We study the systems experimentally by scanning tunneling microscopy, low energy electron microscopy and X-ray photoelectron spectroscopy. When synthesized on graphene, the 2D M-TCNQ MOFs are monophase with M₁(TCNQ)₁ stoichiometry, no alternative structure was observed with slight variation of the preparation protocol. We further demonstrate a remarkable chemical and thermal stability of TCNQ-based 2D MOFs: all the studied systems survive exposure to ambient conditions, with Ni-TCNQ doing so without any significant changes to its atomic-scale structure or chemical state. Thermally, the most stable system is Fe-TCNQ which remains stable above 500 °C, while all the tested MOFs survive heating to 250 °C. Overall, the modular M-TCNQ/graphene system combines the atomic-scale definition required for fundamental studies with the robustness and stability needed for applications, thus we consider it an ideal model for research in single atom catalysis, spintronics or high-density storage media.

中文翻译：

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惰性衬底上非常稳定的金属有机框架：石墨烯上的 M-TCNQ（M = Ni、Fe、Mn）

二维金属有机框架（MOF）的潜在应用要求框架是单相的，并且在原子尺度上定义明确，与支撑基板分离，并在应用条件下保持稳定。在这里，我们提出了三个满足这一难以捉摸的要求的系统：外延石墨烯/Ir(111) 上的 M-TCNQ (M = Ni, Fe, Mn)。我们通过扫描隧道显微镜、低能电子显微镜和 X 射线光电子能谱对系统进行实验研究。当在石墨烯上合成时，二维 M-TCNQ MOF 是单相的，具有 M ₁ (TCNQ) ₁化学计量，没有观察到替代结构，制备方案略有变化。我们进一步证明了基于 TCNQ 的 2D MOF 具有显着的化学和热稳定性：所有研究的系统都可以在环境条件下存活，而 Ni-TCNQ 的原子尺度结构或化学状态没有任何显着变化。在热学上，最稳定的系统是 Fe-TCNQ，它在 500 °C 以上保持稳定，而所有测试的 MOF 都可以在加热到 250 °C 时存活。总体而言，模块化的 M-TCNQ/石墨烯系统将基础研究所需的原子尺度定义与应用所需的稳健性和稳定性相结合，因此我们认为它是单原子催化、自旋电子学或高密度存储介质研究的理想模型.