Cavity-directed syntheses within self-assembled nano-space

Molecular self-assembly via metal-coordination has been providing a very useful method for the non-covalent synthesis of nanometer-sized molecular architectures. We have been showing that the simple combination of cis-endocapped square-planar Pd(II) complexes with pyridine-based bridging ligands gives rise to the quantitative self-assembly of nano-sized hollow structures such as cages, bowls, tubes, and capsules. These hollow compounds provide unique distinct cavities with their own size and shape and allow the encapsulation of neutral organic molecules at fixed position of the cavities. With an expectation that the subsequent chemical reactions of the guests are highly controlled by the cavities, we have examined the chemical reactions of the encapsulated guests within the hollow compounds. Accordingly, we discuss here cavity-directed synthesis within the self-assembled molecular nano-space where the chemical properties and reactivities of encapsulated molecules are suitably controlled by the confined space.