Properties of singlet- and triplet-excited states of hemicyanine dyes

DANIEL O. MÁRTIRE; WALTER MASSAD; HERNÁN MONTEJANO; MONICA CRISTINA GONZALEZ; PAULA CAREGNATO; LAURA VILLATA; NORMAN A. GARCÍA

CHEMICAL PAPERS

VERSITA

Lugar: Varsovia; Año: 2014 vol. 68 p. 1137 - 1140

0366-6352

The fluorescence emission spectra and fluorescence quantum yields of hemicyanine dyes LDS 698,LDS 722, and LDS 730 were measured in different media. No transient species was detected in the laser flash-photolysis experiments performed with Ar-saturated solutions of the dyes in methanol. However, in the presence of 0.08 M potassium iodide, the absorption of the triplet states was clearly observed. Oxygen consumption measurements in the absence and presence of a chemical trap (furfuryl alcohol) in MeOH : H2O (ϕr = 1 : 1) solutions of the dyes containing KI confirmed the generation of singlet molecular oxygen.