Dynamic rotaxane-branched dendrimers with precisely arranged luminogens for efficient light harvesting

Although the development of artificial light-harvesting systems (LHSs) has attracted increasing attention, the construction of novel artificial LHSs with co-existed various types of precisely arranged luminogens has been still a major challenge. Herein, starting from [2]rotaxane building blocks AN-R or TPE-R functionalized with either anthracene or tetraphenylethene (TPE) moiety, a family of novel rotaxane-branched dendrimers containing two types of energy donors on the branches and one pyrene moiety at the central core as energy acceptor have been successfully constructed through a facile, efficient, and controllable divergent approach. Notably, attributed to the solvent-induced switching feature of the rotaxane branches, the integrated rotaxane-branched dendrimers displayed an interesting dynamic feature. More importantly, as revealed by fluorescence spectra, the resultant rotaxane-branched dendrimers displayed enhanced antenna effects along with the increase of dendrimer generation. Therefore, these rotaxane-branched dendrimers described herein could serve as not only promising platforms for light harvesting but also excellent candidates for the construction of smart supramolecular materials for practical applications.