PHOTOISOMERIZATION DYNAMICS AND SPECTROSCOPY OF THE POLYMETHINE DYE DTCI

Citation
Re. Dipaolo et al., PHOTOISOMERIZATION DYNAMICS AND SPECTROSCOPY OF THE POLYMETHINE DYE DTCI, Journal of physical chemistry, 99(38), 1995, pp. 13796-13799
Citations number
21
Categorie Soggetti
Chemistry Physical
ISSN journal
00223654
Volume
99
Issue
38
Year of publication
1995
Pages
13796 - 13799
Database
ISI
SICI code
0022-3654(1995)99:38<13796:PDASOT>2.0.ZU;2-A
Abstract
Laser absorption spectroscopy, laser-induced fluorescence, and pulsed- laser optoacoustic spectroscopy were used to characterize photophysica l and spectroscopic parameters of the photoisomer of the cyanine dye 3 ,3'-diethylthiacarbocyanine iodide (DTCI), Values for the photoisomeri zation and back-photoisomerization quantum yields (phi(NP) = 0.20 +/- 0.03 and phi(PN) = 0.16 +/- 0.03, respectively), as well. as values fo r absorption cross sections and the energy content of the ground state of the photoisomer, were obtained. The quantum efficiency of fluoresc ence of this species was found negligible. Similar to the findings for DODCI and Merocyanine 540, these results suggest that internal conver sion without passing through an intermediate twisted state is the main deactivation step for the excited photoisomer.