Stoddart’s “blue box” (B⁴⁺), is one of the most iconic molecules in the recent history of chemistry. This rectangular tetracationic cyclophane has not only the ability to complex a wide variety of aromatic guests in organic or aqueous media, but because of the presence of viologen units on its structure, it also behaves as a redox-based molecular switch. In turn, B⁴⁺-based host–guest complexes can translate this responsiveness from the molecular to the supramolecular level, resulting in host-controlled binding. This unique behavior has allowed the development of a wide variety of B⁴⁺-containing (supra)molecular switches and machines, which certainly have inspired a whole generation of supramolecular chemists. Nevertheless, issues, such as synthetic accessibility, structural diversity, or the implementation of new chemical properties (luminescence, pH- or photo-responsiveness, etc.), have restricted somehow the development of new practical applications in the ever-changing realm of modern host–guest chemistry.

中文翻译：

---

剖析“蓝盒子”：构建多用途聚阳离子环芳烃的自组装策略。

斯托达特的“蓝盒”（B ⁴⁺）是最近化学史上最具标志性的分子之一。这种矩形四阳离子环烷不仅具有在有机介质或水性介质中络合多种芳族客体的能力，而且由于其结构上存在紫精单元，因此它还可以作为基于氧化还原的分子开关。反过来，基于B ⁴⁺的宿主-客体复合物可以将这种响应性从分子转化为超分子水平，从而导致宿主控制的结合。这种独特的行为使B ⁴⁺的发展成为可能包含（超）分子的开关和机器，这些无疑启发了整代超分子化学家。然而，诸如合成可及性，结构多样性或新化学性质（发光，pH或光响应性等）的实现等问题在某种程度上限制了现代不断变化的领域中新的实际应用的开发。主客体化学。