Symmetry‐Breaking and Symmetry‐Retaining Morphological Evolution of the Single Crystals of Cyclodextrin Metal‐Organic Frameworks

Abstract

AbstractThe morphological symmetry‐retaining and symmetry‐breaking of single crystals of the γ‐cyclodextrin metal‐organic framework have been achieved via introducing lower symmetric β‐cyclodextrins and α‐cyclodextrins, respectively. β‐cyclodextrins led to a morphological evolution with retained symmetry from cubic to rhombic dodecahedra, while α‐cyclodextrins resulted in the original cubic crystal missing a vertex angle presenting symmetry‐breaking behavior. The crystal structures of rhombic dodecahedra and angle‐deficient crystals were confirmed through X‐ray crystallography, and the mechanisms underlying the morphological transformation evolution were further analyzed. Our work not only provides a rare case realizing two different paths of morphological evolution in one system, but also encourages future efforts towards the evolution of artificial crystal systems in a natural way.