Effect of π-Extended Substituents on Photophysical Properties of BODIPY Dyes in Solutions

Four boron-dipyrrine (BODIPY) based dyes with π-extended substituents in 8-position of dipyrrin ligand have been synthesized and characterized. Photophysical properties of the obtained compounds have been investigated in different individual solvents. Deposits of solvent polarity and viscosity were evaluated. BODIPY with 8-biphenyl substituent was found to be the fluorescent molecular rotor in contrast to more extended substituents. The complex nature of solvent-solute interactions leads to the poor applicability of standard multiparameter approaches to BODIPY solvatochromic properties. Fluorescence intensity was found to increase in case of solvent polarity growth, it is not typical for BODIPY. Taking that into account the BODIPY with π-extended substituents could be used for fluorescence viscosity measurements, and as the fluorescent media polarity indicators in analytical chemistry and biochemistry.     

Effect of Metal Cation on Absorption and Fluorescence Spectra of Metal Complexes of 8-Hydroxyquinoline∗

8-Hydroxyquinoline complexes of Na(I), Ca(II), Mg(II), Zn(II), Mn(II), Cu(II), Al(III), In(III) and La(III) are synthesized. Photoluminescence and UV-vis absorption spectra of them are reported. Except complexes of Cu(II), and Mn(II), these complexes show photoluminescence. With the increase of polarization force of metal cation, their photoluminescence peaks reveal red-shift and two broad absorption bands in UV-vis absorption spectra appear split and red-shift.

     

Influence of the Structure of Water–Alcohol Solutions of Dyes on Their Molecular Association

The spectral and luminescence characteristics of water and water–ethanol solutions of dyes have been investigated. The efficiency of the process of association of dye molecules and the structure of the complexes formed depending on their concentration and the solvent composition have been established. The presence of inhomogeneities in the distribution of dissolved complex molecules in the water matrix which determine the high efficiency of the association processes in water solutions as compared with other solvents is shown. The characteristic sizes of these inhomogeneities have been estimated.     

Comments on the paper “Detection of the Absorption Spectra of Water Clusters under Atmospheric Conditions”

A numerical simulation has been performed, indicating that the statement on the detection of water dimer absorption by V.I. Serdyukov et al. in Pis’ma Zh. Eksp. Teor. Fiz. 89, 12 (2009) [JETP Lett. 89, 10 (2009)] had been premature. Most of the revealed induced absorption can be attributed to water monomers.     

Quantum–Chemical Studies on the Superposition of Absorption Bands in the Carbonyl Region of the IR Spectra of Acetylacetone

Using the MO LCAO SCF method in the PM3 approximation, we have investigated the influence of various internal motions of the enol molecule of acetylacetone on the harmonic vibrational frequencies of the C=O and C=C groups. The results of the investigation are discussed with reference to the available literature data on vibrational spectra of acetylacetone and its substituted derivatives. They suggest that the nature of the wide intense IR band 1620 cm^–1 in the spectra of acetylacetone vapors responsible for the absorption of its enol double bonds and its temperature dependence are determined by the tunnel mechanism of enol proton motion in the H–bond channel, the probability of whose realization is controlled by the internal rotation of methyl substituents.     

Temperature Effect on the IR Absorption Spectra of Hydrogen Bonded (N[sbnd]…N)+ Homoconjugated Cations

Abstract

The effect of temperature on the absorption spectra from 50 to 3200 cm^?1 of a number of amine semiperchlorates and perchlorates of amines with two basic centres in which the hydrogen bridges (N [sbnd] H…N)⁺ are formed, was investigated. Three broad absorption regions may be distinguished in the spectrum, viz., between 100 and 900 cm^?1, 600 and 1800 cm^?1 and 1700 and 2900 cm^?1. The latter one may be assigned to the stretching vibration ν_S (N [sbnd] H…N).

A shift of this band peak (which is usually a doublet at room temperature for aromatic amines) towards longer wavelengths on decreasing the temperature may be an evidence that the bridge becomes shorter. Simultaneously with these changes, most salts under investigation exhibit a strong increase in low-frequency absorption intensity at about 400–600 cm^?1. It may be suggested that this absorption results from a transition between the split levels of the zero vibrational state.     

Effect of alloying on the self-diffusion activation energy in γ-iron

The experimental data on the self-diffusion coefficient of austenite with different chemical compositions obtained by the radioactive isotope method have been analyzed quantitatively. The self-diffusion activation energy in pure γ-iron is shown to be ∼312 kJ/mol. Alloying of austenite with such elements as Mn, Mo, Nb, Ti, and Si (to a lower degree) increases the self-diffusion activation energy, and alloying with C, V, or Cr (for the element content ≥3 at %) decreases it. The empirical formula is derived for calculation of the self-diffusion activation energy in austenite solid solutions with complex composition.     

Effect of Temperature on Parameters of Fluorescence Spectra of Solvatochromic Indicator Solutions in Stationary Phases for Gas–Liquid Chromatography

Journal of Applied Spectroscopy - Luminescence spectra of several polarity indicators, including Coumarin 153 and coronene that were previously studied at room temperature and Nile Red and Pigment...     

Effect of capping on the mechanoluminescence of γ-irradiated ZnS:Cu nanophosphors

Mechanoluminescence (ML) properties of γ-irradiated and non-irradiated capped ZnS:Cu nanophosphors have been investigated. The nanoparticles were prepared by wet chemical method using different capping agents. The samples were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). ML was excited impulsively by dropping a load on to the sample. Two peaks have been observed in the ML intensity versus time curve. It has been found that ML intensity rises with time, attains a maximum and then decays. The ML intensity of γ-irradiated SiO₂ capped ZnS:Cu nanophosphors was found to be the highest amongst the presently investigated nanophosphors. Mechanism of ML has been explained on the basis of piezoelectrically induced charge carrier detrapping model.     

Effect of Electron Delocalization on the “Recoil-Free” Absorption of γ-Ray Photons in Fe1.75V0.25BO4 Warwickite

JETP Letters - Mössbauer spectroscopy is used to study the characteristic features of the crystal lattice dynamics in powdered single crystals of Fe1.75V0.25BO4 warwickite in the temperature...     

Effect of γ-radiation on the strain characteristics of a high-filled wood-plastic composite

The strain rate and the characteristics of the jumps at micro- and nanolevels were measured by the high-precision interferometric method for a wood-plastic composite irradiated to doses of 0–100 kGy. Radiation was shown to strengthen the material and change the characteristics of strain rate and value jumps. Strain jumps and mean-square deviations of the measured strain rate from its smoothened time dependence were determined for micro- and nanosized jumps. The change of these characteristics depending on the radiation dose of specimens was traced. A relation between the characteristics of micrometer jumps and the macroscopic strain was revealed.

     

Absorption Spectra of Gasolines in the Region 1090–1220 nm

The difference absorption spectra of different grades of gasoline (A-76, AI-92, and AI-95) with octane numbers lying within 76–85 have been investigated experimentally in comparison with hydrocarbons: isooctane, benzene, and n-heptane. The spectra obtained contain absorption bands of the CH₃, CH₂, and CH groups and supposedly of the olefin double bond. The possibility of determining the octane number of an unknown grade of gasoline by using the absorption of a measured difference spectrum at one selected wavelength is shown.     

Effect of surface recombination on the amplitude spectrum of variable bias γ-counters

The form of the amplitude spectrum of a photoresistive counter is found by solution of the continuity equation for an infinite semiconductive plate with an instantaneous point source of nonequilibrium charge carriers and a specified surface recombination rate for these carriers and an additional assumption as to the character of -quantum absorption by the photoresistor material. It is thus shown to be possible to construct the spectrum with use of the response function formalism of [1, 2] for each of the signal formation processes (e-p pair generation, photoconductivity kinetics, imposition of equipment noise).Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 97–100, September, 1982.     

Effect of Deuteration on Quasiline Electronic‐Vibrational Spectra of Phthalocyanine

Quasiline electronicvibrational spectra of fluorescence and absorption (excitation of fluorescence in selective recording) of the molecules of phthalocyanine deuterated around the periphery of benzene rings (H₂Phcd ₁₆) and the center of the macrocycle (D₂Phc) are obtained. The vibrational frequencies of the ground state are almost insensitive to this deuteration (except for vibrations with the participation of angular deformations). In excitation spectra, changes in deuteration are more pronounced due to the effects of nonadiabatic vibronic interaction of the vibrational sublevels of the S ₁ state and of the purely electronic level S ₂.     

Effect of Common-Cation CdBVI Compounds on the Properties of Solid Solutions of ZnS–CdBVI Systems

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques - Solid solutions of ZnS–CdBVI systems (B = S, Se, Te), identified as substitutional solid solutions with the...     

Applications of Spectroscopy in the Study of Glassy Solids Part I. Introduction, γ-Ray Spectroscopy (Mössbauer Effect), X-Ray Absorption Fine Structure,UV Absorption,and Visible Spectra

Abstract

Interest in glasses and the amorphous solid state in general, having for a long time been limited t o the separate camps of silicate glass technology and polymer science, has in the last few years become very general. This growth and diversification in scientific interest originates jointly in the discovery and utilization of glasses of quite new types e.g., the chalcogenide glasses, and the recognition by chemists and physicists alike that the glassy state is of very general occurrence in nature, with examples now being known from every class of chemical substance, whether metallic, vander Waals, covalent, or ionic in the interparticle bond character.