AbstractThe 2,7‐diazapyrenium group (DAP2+) combines the features of pyrene, of methylviologen, and of nucleicacid intercalators and may thus present a variety of interesting properties. The cations1and2and the bis‐diazapyrenium species3have been synthesized and shown to bind molecular anions like aromatic polycarboxylates, giving rise to pronounced shifts of1H‐NMR signals, modifications of UV/VIS absorption spectra, and quenching of fluorescence. The complexes formed probably have a face‐to‐face structure, and their stability constants are remarkably high, in particular for the bis‐diazapyrenium cation3which is susceptible to form intercalative chelate complexes such as9(logKs≈ 3 for1, up toca. 7 or more for3a). Neutral molecules like adenine are also bound, but much less strongly. Visible‐light irradiation of Me2DAP2+(1) in presence of various electron donors, such as EDTA, gives the reduced species Me2DAP+wich has been characterized by UV/VIS and ESR spectroscopy. The results indicate that Me2DAP2+(1) functions as amethylviologen analogue, photoactive in visible light. Thus 2,7‐diazapyrenium cations are attractive subunits for incorporation into macropolycyclic structures to give photo‐ and electroactive