Host-stabilized charge-transfer (CT) interactions and supramolecular assemblies built with these interactions are described. A variety of supramolecular assemblies including polyrotaxanes, molecular necklaces, and rotaxane dendrimers were synthesized through the intramolecular or intermolecular host-stabilized CT complex formation using cucurbit[8]uril (CB[8]) and D–A molecules having both electron-donor and electron-acceptor units connected by various types of linkers. Applications, including the design and synthesis of redox-driven molecular machines such as molecular loop locks, development of redox-controllable vesicles and detection of biologically important molecules, are also described.