A water-soluble macrocyclic host is reported, composed of alkoxyanthracene as the donor (D), and 4,4-bipyridinium as the acceptor (A). The intramolecular D–A structure renders the host highly photostable. However, the introduction of a strong electron-donating guest promotes the photodecomposition of alkoxyanthracene, yielding photolyzable host–guest complexes or aggregates.