Nestable Tetrakis(spiroborate) Nanocycles

Multicomponent construction of the tetrakis­(spiroborate) anionic nanocycles was achieved by reacting bis­(dihydroxynaphthalene)­s with tetrahydroxyanthraquinone in the presence of boric acid in a self-organized manner. These nanocycles exhibited selective molecular recognition behavior toward cationic guests such as methyl viologen derivatives. Formation of a supramolecular ring@ring and a guest@ring@ring structure was observed by combining the anionic nanocycle and the vinylogous analog of cyclobis­(paraquat-p-phenylene).