Chapter 8. Cucurbit[8]uril-based 2D and 3D Regular Porous Frameworks

Abstract

For many years, studies on the generation of periodic or regular porosity and their properties and functions have been limited to insoluble solid-state materials. Self-assembly provides a straightforward strategy for the construction of water-soluble porous supramolecular organic frameworks (SOFs) from rationally designed rigid multitopic molecular components and cucurbit[8]uril (CB[8]). The process is driven hydrophobically by CB[8]-encapsulation-enhanced dimerization of the aromatic (CEBA) units that are appended to the multitopic molecules. By using this strategy, a variety of two-dimensional honeycomb-shaped, square, and rhombic SOFs have been constructed, some of which exhibit interesting absorption and sensing functions. From tetraphenylmethane- and [Ru(bipy)3]2+-derived precursors, three-dimensional diamondoid and cubic SOFs can also be generated. The diamondoid frameworks have been revealed to be open carriers for in situ loading and delivery of antitumor drugs, whereas [Ru(bipy)3]2+-cored frameworks are good porous photosensitizing materials for the enrichment of anionic polyoxometalate catalysts for new visible light–initiated reduction of proton to hydrogen gas. The progress well demonstrates the CB[8]-based CEBA strategy in constructing advanced water-soluble functional porous materials from symmetric preorganized aromatic precursors.