Hollow Sphere Formation from a Three-Dimensional Structure Composed of an Adamantane-Based Cage

An
adamantane-based cage with a three-dimensional (3D) framework
was synthesized by the copper-mediated acetylene coupling reaction,
in which two 1,3,5-triethynyladamantane units were linked by phenyldiacetylenic
bridges possessing ester groups. X-ray crystallography revealed that
the cage has an internal space and accommodates a solvent molecule,
which afforded molecular networks through CH/O interactions between
cage molecules. Furthermore, the cage containing six ester groups
spontaneously self-assembled into hollow spherical aggregates with
an average diameter of 230 nm in a mixed solvent.