Graphyne, a novel regularly sp-/sp-hybridized carbon allotrope, has attracted significant interest in synthetic chemistry and various applications. As a promising approach for material synthesis, mechanochemistry has first been successfully applied to fabricate γ-graphyne (γ-GY) which exhibits highest structural stability among graphyne family and possesses fascinating properties like a direct bandgap and unique nanoporosity. The γ-GY skeleton forms via an alkyne nucleophilic cross-coupling reaction induced by intense mechanical energy using hexahalobenzene and calcium carbide as precursors. This mechanochemical strategy is simple, high-yielding, scalable, and commercially viable. This review aims to offer a comprehensive and critical understanding of mechanochemical synthesis of γ-GY. Firstly, the basic concept, physicochemical properties and potential applications of graphyne, especially γ-GY, are introduced. Subsequently, the review summarizes several state-of-the-art synthetic strategies for γ-GY and corresponding representative characterizations. Furthermore, the feasibility of mechanosynthesis for γ-GY is elucidated through the discussion of its origin which involves mechanochemical dehalogenation, and its subsequent development for the synthesis of alkynyl cross-linked carbon derivatives. The reaction mechanism, and controversial factors (including solvent issue, side reaction, and carbonaceous impurities) of the mechanochemical route are adequately outlined and analyzed. Evidence confirms the existence of γ-GY in the as-prepared sample and inevitable generation of by-products such as carbonaceous impurities. Finally, the challenges and future research directions of mechanochemical synthesizing high-quality γ-GY and derivatives (analogues) are proposed.

中文翻译：

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全碳石墨烯材料机械化学制造的批判性评论


石墨烯是一种新型的规则sp-/sp-杂化碳同素异形体，引起了合成化学和各种应用的极大兴趣。作为一种有前途的材料合成方法，机械化学首先成功地应用于制备γ-石墨烯（γ-GY），它在石墨烯家族中表现出最高的结构稳定性，并具有直接带隙和独特的纳米孔隙率等令人着迷的特性。 γ-GY 骨架通过使用六卤代苯和碳化钙作为前体的强机械能诱导的炔亲核交叉偶联反应形成。这种机械化学策略简单、高产、可扩展且具有商业可行性。本综述旨在对 γ-GY 的机械化学合成提供全面和批判性的理解。首先介绍了石墨炔，特别是γ-GY的基本概念、理化性质和潜在应用。随后，综述总结了几种最先进的 γ-GY 合成策略和相应的代表性表征。此外，通过讨论其涉及机械化学脱卤的起源，及其随后用于合成炔基交联碳衍生物的发展，阐明了γ-GY机械合成的可行性。充分概述和分析了机械化学路线的反应机理和有争议的因素（包括溶剂问题、副反应和碳质杂质）。证据证实所制备的样品中存在 γ-GY，并且不可避免地产生碳质杂质等副产物。最后，提出了机械化学合成高质量γ-GY及其衍生物（类似物）面临的挑战和未来的研究方向。