Lösungsmittel-, Viskositäts-, Säure- und Substituenteneinflüsse auf die Photoisomerisierung und Relaxation symmetrischer Triazacarbocyanine bei 283 bis 323 K

Influence of Solvents, Viscosity, Acid, and Substituents on the Photoisomerization and the Relaxation of Symmetrical Triazacarbocyanine Dyes at 283 to 323 K Photobleaching and the reverse dark reaction of seven symmetrical triazacarbocyanine dyes with different heterocycles were studied dependent on solvent effects (protic and aprotic solvents), on effects of viscosity (glycerol/EtOH mixtures), and on effects of added acid. No effects of dissolved O₂ or added I₂ has been observed. Kinetic data (ΔH^≠, ΔS^≠, and ΔG) of the reverse reaction are given. The effect of the substituents has been studied on two series of substituted triazacarbocyanine dyes. The mechanism of the reverse reaction is discussed.