Interfacial Self-Assembly of Metal Halide Complexes Mediated by a Crown Ether-Based Bola Amphiphile

 Liquid–liquid interfaces provide unique environments for molecular organization and structure formation, enabling the emergence of hierarchical architectures that are difficult to access in bulk solution. In this study, we report the formation of spherical inorganic–organic hybrid architectures through interfacial self-assembly mediated by a crown ether-functionalized bola amphiphile.

 An aqueous phase containing bromostannate species and an organic phase containing the bola amphiphile were brought into contact to induce interfacial assembly. Optical and polarized optical microscopy revealed the formation of spherical domains exhibiting characteristic birefringent patterns. In addition, hierarchical flower-like spherical architectures composed of radially organized crystalline features were observed during the growth process. The morphology and structural evolution of these assemblies were found to be strongly dependent on the composition of the aqueous phase and growth environment, highlighting the important role of the interface in directing assembly and crystallization behavior.

 The formation mechanism of these structures and the relationship between interfacial assembly and crystal growth were investigated. In addition, the interfacial assembly system was extended from bromostannate to other halometallate guests, introducing diverse optical properties and functionalities.