The bleaching dynamics of organic dye molecules in solution have been investigated using 70 fs pulses from a colliding pulse mode-locked ring dye Laser. In addition to ground state relaxation on a nanosecond time scale, a fast partid recovery 1s observed. For the dyes Nile blue, oxazine 720, cresyl
Excited state relaxations of phytochrome studied by femtosecond spectroscopy
✍ Scribed by R. Büchler; G. Hermann; D.V. Lap; S. Rentsch
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 347 KB
- Volume
- 233
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
✦ Synopsis
Femtosecond time-resolved spectroscopic studies with phytochrome in its red light absorbing form (Pr) were performed. Upon excitation of Pr with 75 fs pulses at 618 nm bleaching of the Pr ground state absorption accompanied by a broad transient absorption centered near 725 nm was observed. The stimulated emission of Pr was detected with a delay of about 200 fs. The appearance of stimulated emission coincided with a strong decrease of the transient absorption near 725 nm. From these results it is suggested that Pr is initially excited into a vibrationally unrelaxed state that undergoes relaxation within about 200 fs towards the fluorescing state. From 1 ps after excitation the initially fast relaxation processes were followed by comparatively slower ones. From decay kinetics of bleaching and fluorescence in the first 6 ps after excitation a decay time of about 15 ps was estimated.
📜 SIMILAR VOLUMES
The proton transfer in 2-(2'-hydroxy-5 '-methylphenyl)henzotriazole is studied in nonpolar solvents, where two major ground state conformers are identified. After femtosecond excitation of the predominant species, the hydroxylic proton is transferred to the benzotriazole moiety on a time scale of 10
The femtosecond kinetics associated with intramolecular proton transfer in the electronically excited state of aromatic molecules is investigated. The initial enol structure of 2-(2'-hydroxyphenyl)benzothiazole (HBT) is excited by a femtosecond UV pulse at 3 15 nm and the risetime of the emission of
Transient diffraction spectra and their rise and decay dynamics of a thin copper phthalocyanine film ( = 50 nm thickness) were investigated by femtosecond transient grating spectroscopy using a white-light continuum as a probe pulse. Temporal profiles of first-and second-order diffractions were stro