Daisy chain molecule, as a kind of important mechanically interlocked molecules, has a wide range of applications in artificial molecular machines and intelligent materials because of its unique structure and specificity. Especially the daisy chain molecules with stimulus-response properties have attracted a wide range of interest and attention due to their special stimulus-response stretchability. However, the precise construction of the high-order mechanically interlocked molecules with well-defined topological arrangements of multiple mechanically interlocked units has been a great challenge.

In this study, reseachers present the first successful preparation of a new family of daisy chain dendrimers, in which the individual [c2]daisy chain rotaxane units serve as the branches of dendrimer skeleton. The successful merging of [c2]daisy chain rotaxanes and dendrimers described herein provides not only a brand-new type of high-order mechanically interlocked systems with well-defined topological arrangements of [c2]daisy chain rotaxanes, but also a successful and practical approach toward the construction of supramolecular dynamic materials.

SANS, an instrument at CSNS, has contributed to test solution and solid composite membrane samples, and confirmed that the conformation of each branch of Daisy chain molecule folds after stimulation, resulting in a controllable and reversible size change of the whole. This research is of great significance for the construction of new artificial muscles and the development of dynamic intelligent materials in the future. 

The full publication can be found here at https://pubs.acs.org/doi/abs/10.1021/jacs.0c02475