Dual‐Readout of the Mechanical Response of a Bis‐acridinium [2]Rotaxane

A [2]rotaxane built around a multi‐responsive bis‐acridinium macrocycle has been synthesized. Structural investigation has confirmed the interlocked nature of the molecule, and MD simulations illuminated its conformational dynamics with atomic resolution. Both halochromic and redox‐switching properties were explored to shed light on the mechanical response and electronic changes that occur in the bis‐acridinium [2]rotaxane. The topology of the rotaxane led to different mechanical behaviors upon addition of hydroxide ions or reduction that were easily detected by UV/Vis spectroscopy and electrochemistry. The chemochromic and electrochemical properties of a switchable bis‐acridinium [2]rotaxane led to two different mechanical responses and an ON/OFF reading of the motion in the assembly. This work could lead to the use of the acridinium core as a recognition unit for radical templating through π‐mer formation.