Mechanically interlocked molecules (MIMs) have attracted chemists’ attention in the past few decades due to their applications in multicomponent molecular level devices and machines.
As one kind of MIM, bistable [2]rotaxanes play an important role in the design of molecular devices because of their adjustable physical and chemical properties. In this type of rotaxane, a macrocycle with two distinct, well-separated recognition sites on the thread component can be changed in response to external stimuli. Symmetrical functional [n]rotaxanes with repeating bistable [2]rotaxane arms have attracted much attention because of their charming structures, tunable properties, and synthetic challenge.
Da-Hui Qu and colleagues, East China University of Science and Technology, Shanghai, designed and constructed a bistable bis-branched [3]rotaxane with a perylene bisimide (PBI) chromophore core and two mechanically interlocked [2]rotaxane arms including a diferrocene-functionalized dibenzo-24-crown-8 ring (pictured).
The shuttling motion of the macrocycles along the thread component is accompanied by visual fluorescent change due to distance-dependent photoinduced electron transfer from the ferrocene units to the PBI fluorophore. This kind of rotaxane has potential value for constructing more sophisticated MIMs with controllable functions.
- A Perylene-Bridged Switchable [3]Rotaxane Molecular Shuttle with a Fluorescence Output,
Zhan-Qi Cao, Hong Li, Jian Yao, Lei Zou, Da-Hui Qu, He Tian,
Asian J. Org. Chem. 2014.
DOI: 10.1002/ajoc.201402201
