Aggregation of Anionic Cyanine Dyes by Electron-Withdrawing Organic Polycations

Abstract

It is shown that bis-quaternary salts of 4,4′-dipyridyl (viologens) stimulate the J-aggregation of anionic cyanine dyes in an aqueous solution. It is concluded that the behavior of multiply charged inorganic and organic cations is similar: both types of polycations result in the self-assembly of ordered J-aggregate structures from dimers. It is found that multichromic J-aggregates with the participation of cationic cyanine dyes are formed on the “platform” of J-aggregates built of anionic cyanine dyes and dications of viologens. Thus, we discuss the self-assembly of highly organized structures in which, along with photosensitive exciton semiconductors from organic dyes, π-conjugated organic molecules are included that can participate in secondary dark processes of separation of charges of Frenkel excitons.