Expandable rotational origami nano-boxes made by giant shape amphiphile

Dynamic cavity is widespread in living matter and supramolecular scaffolds. Generally speaking, flexible building block as a segment is used to realize dynamic cavities building in artificial molecules and materials. However, the incorporation of rigid synthetic supramolecular scaffolds with flexible cavity motion remains rare. Inspired by rotational origami patterns, giant shape amphiphile (GSA), POSS-NDI-POSS (PNP), assembled into an origami nano-box with feature of rotational expansion. The open/close of cavity and size control of PNP host can be adjusted by rotational offset between adjacent PNP in supramolecule entities. The rotational offset of 150°, 130° and 0° were observed when the host nano-box presented close, half-open and fully-open state, respectively. The rotational expansion of PNP trigged by gaseous arenes makes PNP as a novel nonporous crystal. Compared with conformation change in flexible building segment, rotational expansion in acyclic host (PNP) provides a new strategy for the development of rigid segment to build adaptive host-guest recognition.