Transient hole‐burning and time‐resolved fluorescence spectra of dye molecules in solution: Evidence for ground‐state relaxation and hole‐filling effect

AbstractThe ability of new chelate ligands, benzoxazol-5-yl-alanine derivatives substituted in position 2 by heteroaromatic substituent, to form complexes with selected metal ions in acetonitrile are studied by means of absorption and steady-state and time-resolved fluorescence spectroscopy. Among the ligands studied, only azaaromatic derivatives form stable complexes with transition metal ions in the ground state. Their absorption bands are bathochromically shifted enabling to use those ligands as ratiometric sensors. The fluorescence of each ligand is quenched by metal ions, however, in the presence of Cd(II) and Zn(II) ions a new red shifted emission band is observed.

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Фотофизические процессы в молекулах галогенпроизводных флуоресцеина в анионных обратных мицеллах

Журнал технической физики ◽

10.21883/os.2020.12.50319.181-20 ◽

2020 ◽

Vol 128 (12) ◽

pp. 1842

Author(s):

О.И. Волкова ◽

А.А. Кулешова ◽

Б.Н. Корватовский ◽

А.М. Салецкий

Keyword(s):

Reverse Micelles ◽

Heavy Atom ◽

Rotational Correlation Time ◽

Dye Molecules ◽

Time Resolved Fluorescence ◽

Time Resolved ◽

Micellar Systems ◽

Aqueous Micellar Solutions ◽

Derivatives Of ◽

Rotational Correlation

Studies of photophysical processes in aqueous micellar solutions of halogen derivatives of fluorescein: Eosin( E), Erythrosin (ER) and Bengal Rose (BR) by methods of dynamic light scattering, stationary and time-resolved fluorescence spectroscopy were carried out. It was found that the introduction of dye molecules into reverse AOT micelles causes an increase in their hydrodynamic radii Rh. The time-resolved fluorescence of the studied dye molecules in reverse micelles was measured. A decrease in the average time of the excited state with an increase in Rh for E, ER, and BR was found, which is associated with an increase in the mobility of water molecules and a decrease in the effect of geometric restriction of dye molecules. The degrees of anisotropy of the fluorescence r of dye molecules in reverse micelles were measured. It was shown that in micellar systems r is greater than in aqueous solutions and decreases with increasing Rh. The rotational correlation time for the studied dye molecules in micellar systems is determined, which decreases for all the studied dyes with an increase in Rh, indicating a decrease in the microviscosity of the confined aqueous medium inside the micelle. In this case , i.e., the value of the time of the rotational correlation is affected by the "heavy atom effect".

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An Introduction to Time-Resolved Pump/Probe Spectroscopy

Applied Spectroscopy ◽

10.1366/0003702854248511 ◽

1985 ◽

Vol 39 (3) ◽

pp. 444-451 ◽

Cited By ~ 16

Author(s):

F. E. Lytle ◽

R. M. Parrish ◽

W. T. Barnes

Keyword(s):

Absorption Spectra ◽

Ground State ◽

Fluorescence Spectra ◽

Excited State Absorption ◽

Time Dependent ◽

Triplet Excited State ◽

Ground State Absorption ◽

Time Resolved ◽

Pump Probe ◽

Probe Spectroscopy

The construction and operating principles of a two-color pump/probe spectrometer are described. This instrument is capable of obtaining ground-state absorption spectra, both singlet-singlet and triplet-triplet excited-state absorption spectra, photoproduct spectra, and stimulated fluorescence spectra. In addition, time-dependent measurements can be made with an impulse response of 250 ps and a free temporal range of 13 ns.

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