Allosteric control, one of Nature’s most effective ways to regulate functions in biomolecular machinery, involves the transfer of information between distant sites. The mechanistic details of such a transfer are still an object of intensive investigation and debate, and the idea that intramolecular communication could be enabled by dynamic processes is gaining attention as a complement to traditional explanations. Mechanically interlocked molecules, owing to the particular kind of connection between their components and the resulting dynamic behavior, are attractive systems to investigate allosteric mechanisms and exploit them to develop functionalities with artificial species. We show that the pK_a of an ammonium site located on the axle component of a [2]rotaxane can be reversibly modulated by changing the affinity of a remote recognition site for the interlocked crown ether ring through electrochemical stimulation. The use of a reversible ternary redox switch enables us to set the pK_a to three different values, encompassing more than seven units. Our results demonstrate that in the axle the two sites do not communicate, and that in the rotaxane the transfer of information between them is made possible by the shuttling of the ring, that is, by a dynamic intramolecular process. The investigated coupling of electron- and proton-transfer reactions is reminiscent of the operation of the protein complex I of the respiratory chain.

变构控制是自然界调节生物分子机器功能的最有效方法之一，它涉及远距离站点之间的信息传递。这种转移的机制细节仍然是深入研究和辩论的对象，并且分子内通信可以通过动态过程实现的想法作为对传统解释的补充而受到关注。机械联锁的分子，由于其成分之间的特殊联系和由此产生的动态行为，是研究变构机制并利用它们开发人工物种功能的有吸引力的系统。我们证明了 pK _a位于 [2] 轮烷轴组件上的铵位点可以通过电化学刺激改变远程识别位点对联锁冠醚环的亲和力来可逆地调节。使用可逆三元氧化还原开关使我们能够将 pK _a设置为三个不同的值，包括超过七个单位。我们的结果表明，在轴中，两个位点不通信，而在轮烷中，它们之间的信息传递是通过环的穿梭，即通过动态的分子内过程实现的。所研究的电子和质子转移反应的耦合让人想起呼吸链的蛋白质复合物 I 的操作。