L. V. Levshin

Influence of the Structure of a Macromolecular System on the Processes of Association of Molecules of Rhodamine 6G in Aqueous‐Polyelectrolytic Solutions

The processes of association of rhodamine‐6G molecules in aqueous solutions of polyacrylic acid are studied by spectroscopic methods. The efficiency of formation of the dimers of rhodamine 6G as a function of the concentration of the polyelectrolyte and its chain length is established. The angles between monomer molecules in the dimers of rhodamine 6G are determined for different concentrations of the polyacrylic acid and lengths of the polyion chain.

PHOSPHORESCENCE OF MOLECULES OF POLYCYCLIC AROMATIC HYDROCARBONS IN AQUEOUS MICELLAR SOLUTIONS OF SODIUM DODECYLSULFATE AT ROOM TEMPERATURE

Deactivation of the excited states of pyrene, benzanthracene, and fluorene molecules in aqueous micellar solutions of sodium dodecylsufate is studied using steady and pulsed fluorimetry. Quenching of the singlet states of polyatomic hydrocarbons by thallium ions is considered. Effective, micellar, and biomolecular constants for the quenching rate are obtained. Phosphorescence constants for the aforementioned compounds are determined. Reasons behind the possibility of observing phosphorescence of polyaromatic compounds in micellar solutions at room temperature are ascertained.

Regularities of triplet-triplet annihilation of aromatic hydrocarbons in aqueous micellar solutions of sodium dodecyl sulfate

Investigation of deactivation processes in triplet states of a series of aromatic hydrocarbon molecules (antracene, 1,2-benzantracene, and 3,4-benzpyrene) made it possible to reveal the presence of triplet-triplet annihilation of the molecules in aqueous micellar solutions of sodium dodecyl sulfate. It is shown that the effect of microheterogeneous solutions on the process of triplet-triplet annihilation manifests itself in an increase in the probability of excimerization upon dissociation of triplet pairs of 1,2-benzantracene and 3,4-benpyrene molecules compared to one-component solutions.

Spectral luminescence studies of eosin solvation in water-alcohol mixtures

The authors investigate the effects of solvation of eosin molecules in binary water-propanol mixtures with the goal of assessing eosin as a candidate dye laser material. The fluorescence was measured with a Hitachi spectrofluorimeter and the absorption spectra were taken on a Specord spectrophotometer. Absorption and fluorescence were measured for different amounts of propanol in the solvent. Data are also given on excitation and de-excitation kinetics between ground and excited states. Values for quantum yields of fluorescence and phosphorescence, average excited state lifetime, and molecular volume of the dye with the solvated shell are tabulated.

Photophysical properties of lasing mixed solutions of oxazine 17 and rhodamine 6G

This paper presents the results of the effect of triplet states of the donor component, for which Rhodamine 6G was used, on the lasing characteristics of lamp-pumped solutions of this dye, oxazine. The energy and spectral properties are studied and the results analyzed.

Luminescence of adsorbed erythrosine molecules in a system consisting of a semiconductor and a molecular laminated dielectric

It has been shown earlier [i] that the deactivation of photoexcited dye molecules adsorbed on the real surface of a semiconductor can stimulate electron transitions from traps of the surface phase into the bulk of the semiconductor. Additional information on such interactions can be obtained from the luminescence spectrum of the adsorbed molecules. The simultaneous investigation of the spectra and the charge of the surface traps in a semiconductor makes it possible to determine the paths of migration of the excitation energy of dye molecules in both the adsorbed phase and in the solid material.