Cis-, Trans-Aggregates of Thiatrimethine Cyanine Dyes

摘要

Studying the equilibrium between dimers and J-aggregates of meso-ethylthiatrimethine cyanines in water solutions showed that there are two J-aggregate forms of dyes that depend on the structure of dyes and temperatures. The formation of two J-aggregates is connected to the existence of two isomers (cis-, and trans) of dyes in a solution, the equilibrium between which is determined by the structure of dye and temperature. We assume that the short-wave J-aggregate is the J_(cis)-aggregate and is formed from cis-dimers and the longwave is accordingly the J_(trans)-aggregate, which is formed from a trans-dimers.