Some π-molecular radicals typically exist in solution as π-dimers with metastable characteristics. Therefore, attempting to improve the stability of radical π-dimers is a fascinating endeavor. Herein, a series of hydroxyl-functionalised isolated perylene bisimide anionic radical π-dimers were obtained by using intramolecular hydrogen bond assistance in a one-step process for the first time. It is also found that these radical π-dimers exhibit solvatochromism and acid-base discoloration, when the intermolecular hydrogen bonds are disrupted. Perylene bisimide anionic radical π-dimers exhibit unique properties such as solvatochromism and acid-base discoloration. These characteristics make them suitable for ultra-sensitive colorimetric and fluorescent dual-signal detection of amines. Among them the π-dimer achievable the lowest detection limits of 0.13 ppb, 0.02 ppb and 0.049 ppb for primary, secondary and tertiary amines, respectively. Additionally, colorimetric films prepared using these radical π-dimers demonstrate high sensitivity, enabling detection of amines at ppb levels. We believe that this class of radical π-dimers could be develop into a new class of environmental stimuli-responsive materials.

中文翻译：

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基于分离苝双酰亚胺阴离子自由基π-二聚体的胺的设计、合成、溶剂化显色和比色检测


一些π-分子自由基通常以具有亚稳态特性的π-二聚体存在于溶液中。因此，尝试提高自由基 π-二聚体的稳定性是一项令人着迷的努力。在此，首次利用分子内氢键辅助一步法获得了一系列羟基功能化的分离苝双酰亚胺阴离子自由基π-二聚体。还发现，当分子间氢键被破坏时，这些自由基π-二聚体表现出溶剂化变色和酸碱变色。苝双酰亚胺阴离子自由基π二聚体表现出独特的性质，例如溶剂化变色和酸碱变色。这些特性使它们适用于胺的超灵敏比色和荧光双信号检测。其中π-二聚体对伯胺、仲胺和叔胺的最低检测限分别为0.13 ppb、0.02 ppb和0.049 ppb。此外，使用这些自由基 π-二聚体制备的比色膜表现出高灵敏度，能够检测 ppb 水平的胺。我们相信这类自由基π二聚体可以发展成为一类新型的环境刺激响应材料。