Spectral-luminescent Properties Research Articles

Synthesis and Spectral-Luminescent Properties of Sodium-Modified Bismuth Germanate Glasses

Synthesis and Spectral-Luminescent Properties of Sodium-Modified Bismuth Germanate Glasses

Spectral-luminescence properties of PV corrolazines with axial alkoxide ligands

New phosphorus(V) complexes of octaphenyl substituted tetrapyrazinocorrolazines (TPyzCA) containing in the axial positions alkoxide ligands [TPyzCAP(OC2H4X)2] (X = Pr, NMe2, OH) were synthesized using the one-pot procedure and effect of acid on their spectral luminescence and photochemical properties was studied. The presence of fused pyrazine rings increases the ability to bind axial ligands compared to benzo-fused corrolazine (TBzCA). Excited state properties are strongly dependent on the solvation effects. The effect of excited state quenching by photoinduced electron transfer is observed only for the dimethylaminoethoxide complex of TPyzCA in polar solvents, like THF or DMSO. Still, it is absent in dichloromethane, toluene, and for TBzCA derivatives. The hydroxyethoxide complex of TPyzCA and dimethylaminoethoxide complex of TBzCA exhibit efficient fluorescence and high singlet oxygen generation ability in DMSO solution.

Influence of supramolecular self-assembly of oppositely charged Co- and Sn-porphyrins on the their spectral-luminescent properties in aqueous and aqueous micellar media of ionic surfactants

The processes of supramolecular self-assembly of Co(III)-meso-tetra-(4-trimethylammoniophenyl)porphyrin (CoP) and bis-(4-(1-imidazolyl)-phenol)-Sn(IV)-meso-tetra(4-sulfophenyl)porphyrin (SnP) were studied using electronic, steady-state and time-resolved fluorescence, one- and two-dimensional NMR spectroscopy in aqueous media. The main product of such interaction at a 2:1 M ratio of Co and Sn porphyrinates was found to be supramolecular porphyrin trimer CoP–SnP–CoP formed due to donor-acceptor, hydrogen and electrostatic interactions. The distinctive features of the resulting trimer are: significant distortion of the spatial structure of the Co-porphyrin fragments and strong quenching of the Sn-porphyrin macrocycles fluorescence (by 70 %). The distortion of the spatial structure of Co porphyrinates is in good agreement with the quantum chemical calculations as well as with the electronic and NMR spectroscopy data. Adding surfactants – both anionic (Cetyltrimethylammonium bromide - CTAB) and cationic (Sodium dodecyl sulfate - SDS) – even at concentrations below the critical micelle concentration (CMC) leads to the supramolecular trimer destruction. In solutions of ionic surfactants, supramolecular trimer destruction is caused by the interaction of either the peripheral macrocycles of the trimer (CoP) with SDS micelles (premicellar aggregates) or the central macrocycle (SnP) with CTAB micelles (premicellar aggregates). This process is prolonged and the rate of trimer destruction depends on the surfactant concentration. The sizes of the CTAB and SDS micelles solubilized with porphyrin molecules were established by dynamic light scattering. In general, surfactant additions lead to an increase in the SnP fluorescence at least due to the destruction of the supramolecular self-assembly, as well as due to the changes in the state of its microenvironment.

Spectral Luminescent Properties of Alkaline Earth Fluoride Crystals Implanted with Silver Ions

Spectral Luminescent Properties of Alkaline Earth Fluoride Crystals Implanted with Silver Ions

Review of Research data on the poison of the Transcaucasian viper Macrovipera Lebetina obtusа in Azerbaijan

This work presents literature data from studies to determine the influence of environmental factors on the biophysical and toxicological characteristics of the venom of the Transcaucasian viper, as well as to identify the degree of influence of pollutants, ionizing and electromagnetic radiation on the activity of zootoxin. The results of the influence of heavy metals on the spectral characteristics of viper venom, data on the study of the activity of radionuclides in the venom of viper, caught from various biotopes of Azerbaijan, data on the study of the influence of γ-radiation on the physic-chemical properties of viper venom, toxicity, on spectral-luminescent properties and kinetics are presented. luminescence, on the biophysical and pharmacological properties of viper venom. Data from studies on the production of heterocontact indium monoselenide (InSe) of p-type conductivity with crystals of snake venom are presented, electrical characteristics are given, as well as results on the influence of indium monoselenide (InSe) on the biophysical characteristics of snake venom, and conditions for radiation sterilization of viper venom are given.

Spectral-Luminescent Properties of 5-(2-Hydroxyphenyl)-3-methyl-1-(quinolin-2-yl)-1H-1,2,4-triazole and Its Complex with Beryllium(II)

Spectral-Luminescent Properties of 5-(2-Hydroxyphenyl)-3-methyl-1-(quinolin-2-yl)-1H-1,2,4-triazole and Its Complex with Beryllium(II)

Synthesis and Design of Metalloporphyrin Oligomers with Temperature-Assisted Spectral-Luminescent Properties

Synthesis and Design of Metalloporphyrin Oligomers with Temperature-Assisted Spectral-Luminescent Properties

Synthesis and Study of the Optical and Spectral-Luminescent Properties of LuAG:Ce Ceramic

Synthesis and Study of the Optical and Spectral-Luminescent Properties of LuAG:Ce Ceramic

4,7-(bis(octyloxy)-3-(quinoline-2-ylmethylene)isoindoline-1-one and its boronflouride complex. synthesis and spectral-luminescent properties

4,7-Bis(octyloxy)isoindoline-1,3-dione was obtained by reacting 3,6-bis(octyloxy)phthalonitrile with sodium butoxide in butanol, followed by treatment with hydrochloric acid. Its condensation with quinaldine in the presence of zinc oxide leads to the formation of ( E , Z )-4,7-bis(octyloxy)-3-(quinolin-2-ylmethylene)isoindolin-1-one, which was treated with BF3۰Et2O in the presence of triethylamine in toluene to give a new unsymmetrical analogue of BODIPY - ( Z )-2-(difluoroboryl)-4,7-bis(octyloxy)-3-(quinolin-2-ylmethylene)isoindolin-1-one. The complex exhibits a Stokes shift of 25 nm and a high relative fluorescence quantum yield (0.68). To support the experimental data, DFT and TD-DFT calculations were performed.

Alginate–Chitosan Polyelectrolyte Complexes As Carriers for Fluorinated Tetraphenylporphyrin in Photosensitizing Systems of Singlet Oxygen Generation

Water-insoluble photosensitizing (PS) systems active in the generation of singlet 1O2 oxygen are obtained by immobilizing fluorinated tetraphenylporphyrin (FTPP) from a solution in acetone on films of polyelectrolyte complexes based on sodium alginate (SA) and chitosan (CT), and on solid water-insoluble gels of alginate and chitosan. The obtained polymer PS systems are used to establish the intensity of the photoluminescence of singlet oxygen in D2O and the activity of the photocatalytic oxidation of tryptophan in water. It is shown that the photocatalytic activity in the tryptophan oxidation of fluorinated tetraphenylporphyrin immobilized on a SA–CT polyelectrolyte complex and alginate solid gel is higher than that of FTPP immobilized on chitosan solid gel. Spectral-luminescent properties of polysaccharide–FTPP systems and the surface structure of carriers are studied via atomic force microscopy to determine the mechanism of the increase in porphyrin activity when it is fixed on alginate-containing carriers. It is suggested that aspects of the supramolecular structure of solid gels are responsible for the increase in the photocatalytic activity of FTPP upon immobilization on alginate-containing polysaccharide systems.

Spectral-luminescence, redox and photochemical properties of AlIII, GaIII and InIII complexes formed by peripherally chlorinated phthalocyanines and tetrapyrazinoporphyrazines

Complexes of Al[Formula: see text], Ga[Formula: see text] and In[Formula: see text] with peripherally chlorinated phthalocyanine (Cl8PcM) and tetrapyrazinoporphyrazine (Cl8TPyzM) were prepared and studied using spectral and electrochemical methods. DFT calculations were used to reveal the peculiarities of their molecular and electronic structure. Peripheral chlorination of phthalocyanine complexes increases their electron affinity and the first reduction of [Cl8PcM] is observed at −0.25 – −0.35 V (by 0.2 – 0.3 V easier than for [PcM]). Additional azasubstitution further increases the acceptor properties of the macrocycle and [Cl8TPyzM] are reduced at −0.16 V. Among [Cl8PcM] only the Ga[Formula: see text] complex is stable to photooxidation, while among [Cl8TPyzPzM] it is the only one undergoing photoreduction. Fluorescence quantum yields ([Formula: see text] and lifetimes ([Formula: see text] as well as the ability to generate singlet oxygen ([Formula: see text] were determined. The [Formula: see text] values show typical dependence on the central metal Al > Ga >> In and are decreased upon the introduction of chlorine atoms in the peripheral and especially in the axial position. At the same time, azasubstitution in the benzene ring has a minor influence on the [Formula: see text] values but strongly shortens [Formula: see text] (from ca 6 to ca 2 ns). The Ga[Formula: see text] complexes have the highest ability to generate 1O2 and can be considered as effective photosensitizers, especially [Cl8TPyzPzGa(OH)] ([Formula: see text] = 0.87 in slightly acidified solution). Spectral properties in a strongly acid medium were also studied and it was observed that [Cl8PcM] are consequently protonated on meso-nitrogens.

Erratum to: Synthesis, Spectral-Luminescent, and Ionochromic Properties of a Rhodamine B Derivative Containing a Terminal (4-Hydroxybenzyl)triphenylphosphonium Chloride Substituent

Erratum to: Synthesis, Spectral-Luminescent, and Ionochromic Properties of a Rhodamine B Derivative Containing a Terminal (4-Hydroxybenzyl)triphenylphosphonium Chloride Substituent

Design and spectral-luminescent properties of a triad consisting of two BODIPY chromophores axially bound to a Sn(IV)-porphyrin in aqueous and aqueous micellar media

In this work, we designed and studied the emissive properties of a triad consisting of two BODIPY chromophores axially bound to a Sn(IV)-porphyrin via a methylphenolate bridge in aqueous and aqueous micellar media. It has been shown that the fluorescent properties of the porphyrin fragment of the triad, due to photoinduced energy transfer from the axial fragments to the macrocycle, are most sensitive to small changes in viscosity in the range from 3 to 6 cP, which corresponds to the viscosity of the blood of a healthy person (4–6 cP). The localization of the triad in the spherical CTAB micelles increases its emission in aqueous media. The structure–property dependencies established in the study can be applied to design molecular devices for sensing local viscosity of aqueous and aqueous micellar media, which could be of great interest for non-contact detection of physical properties of intracellular or lymphatic fluids.

Synthesis and aggregation-induced emission of (<i>z</i>)-6-alkylamino-2-amino-4-(2-aryl-1-cyanovinyl)pyridine-3,5-dicarbonitriles

( Z )-6-alkylamino-2-Amino-4-(2-aryl-1-cyanovinyl)pyridine-3,5-dicarbonitriles were obtained by reaction of ( Z )-2-amino-4-(2-aryl-1-cyanovinyl)-6-chloropyridine-3,5-dicarbonitriles with various amines, including biologically active ones. The study of the spectral-luminescent properties showed the solid state fluorescence with a maxima at 472-562 nm and its absence in solutions. An increase in the volume fraction of water in solutions above a certain level caused the appearance of fluorescence due to the formation of aggregates. The enhancement of fluorescence upon addition of the viscous solvent glycerol confirmed the presence of aggregation-induced emission of the synthesized compounds.

SYNTHESIS AND STUDY OF THE OPTICAL AND SPECTRAL-LUMINESCENT PROPERTIES OF LuAG:Ce CERAMICS

In this study, LuAG:Ce ceramic powders with compositions of Lu2.98Ce0.02Al5O12 and Lu2.93Ce0.07Al5O12 were synthesized using chemical precipitation. Luminescent ceramic samples were then produced from these powders by vacuum sintering green bodies in the temperature range of 1600 – 1800 ?C. The study aimed to investigate the effect of cerium concentration and vacuum sintering temperature on the optical properties of LuAG:Ce ceramics. The spectral luminescence properties of the LuAG:Ce ceramic samples were analyzed. Results showed that the luminescence intensity was dependent on the activator concentration and vacuum sintering temperature. Additionally, a shift in the maxima of the luminescence spectral bands of the LuAG:Ce ceramics was observed when varying the vacuum sintering temperature within the 1600 – 1800 ?C range.

INFLUENCE OF CERIUM CONCENTRATION AND SINTERING ATMOSPHERE ON THE PHASE COMPOSITION AND LUMINESCENT PROPERTIES OF Y2.98-хCeхAl5.02О12 CERAMICS

The phase composition and spectral-luminescent properties of ceramic samples obtained from oxide compositions with the general formula Y2.98-хCeхAl5.02О12 (x = 0.05, 0.10, 0.20, 0.30, 0.45, 0.60 formula units (f.u.)) were investigated. It was found that the phase composition of the ceramic powders depended significantly on the concentration of cerium and the calcination atmosphere. The maximum concentration of cerium cations in the garnet lattice was determined to be approximately 0.1 f.u. when calcined in air, and approximately 0.16 f.u. when calcined in the argon – hydrogen atmosphere. The photoluminescence of the ceramic samples was studied when excited by a laser with a wavelength of 445 nm. It was observed that ceramic samples sintered in argon and hydrogen had a higher luminescence intensity compared to samples synthesized in a vacuum. The possibility of shifting the wavelength of the maximum luminescence intensity from 546 nm to 570 nm by changing the cationic composition and sintering conditions of the ceramics was demonstrated. Additionally, the negative effect of oxidative annealing of ceramic samples on the intensity and position of luminescence maxima in Y2.98-хCeхAl5.02О12 oxide compositions heavily doped with cerium was shown.

Fabrication and optical properties of YSAG:Cr optical ceramics

YSAG:Cr3+ optical ceramics with compositions Y2.8Sc1.2Cr0.005Al3.995O12, and Y2,88Сr0,005Sc0.2Al4,915O12 were fabricated for the first time. The linear transmittances of the ceramic samples exceeded 80% in the visible and IR regions. It was observed that as the concentration of scandium in YSAG:Cr3+ solid solutions increased, the refractive index of ceramics at a wavelength of 632.8 nm increased from 1.828 ± 0.005 to 1.857 ± 0.005. The effect of scandium cations on the spectral-luminescent properties of Cr3+ cations in the crystal lattice of yttrium-scandium-aluminum garnet was also investigated. It was demonstrated that as the scandium content in dodecahedral site increased from 4 to 50 at%, the effective lifetime of excited states of Cr3+ cations increased from 1.71 ms to 2.72 ms. On the contrary, as scandium content in octahedral site increased, the effective lifetime of excited states of Cr3+ cations decreased from 1.71 ms to 0.71 ms.

Preparation, luminescence, and application of LiMeBO3 borates, Me = Mg, Ca, Sr, Ba, Zn, Cd. Review

The review summarises and analyses data on the preparation, structure, and spectral-luminescent properties of LiMeBO3-based borates, Me = bivalent metal. These polycrystalline borates are prepared traditionally by solid-phase reactions and self-propagating high-temperature synthesis and its modifications based on a combustion reaction. Frameworks of lithium borates with alkaline earth metals, zinc, and cadmium are formed from large metal polyhedra between which there are boron-oxygen triangles isolated from each other. Doping with rare-earth and heavy metal ions leads to the formation of solid solutions which normally have defective structures. Doped activator ions often become the main part of the luminescence centre in the phosphor. The luminescent properties of ions of rare-earth elements arise from the possibility of electronic transitions between states within the 4f-configuration. The paper discusses the most likely mechanisms of charge compensation during heterovalent substitution in LiMeBO3 borates (co-doping and formationof cation vacancies). It is shown that charge compensation during the combined introduction of ions of REEs and alkali metals into the structure has a positive effect on the emission yield. The review considers the results of thermoluminescent, upconversion, and photoluminescent properties and processes and phenomena that cause them. It also explains the mechanism of resonance energy transfer from the sensitiser to the activator using the example of Yb3+→Er3+. It discusses the possibility of using the considered borates as phosphors that emit green, blue, and red light in white LEDs and as effective materials for personnel neutron dosimetry and the dosimetry of weak ionising radiation

Phosphorescence of hexachlorosubstituted subphthalocyanine and its pyrazine analogue

Spectral luminescence, kinetic and energetic properties of hexachlorosubphthalocyaninatoboron(III) chloride and its azaanalogue containing fused pyrazine fragments instead of benzene rings were studied at 298 and 77 K. Weak phosphorescence of complexes was detected and characterized in near-infrared region of spectrum, its parameters depend substantially on the presence of methyl iodide due to its external effect of heavy atom in solutions. Quantum yields of photosensitized formation of singlet oxygen were determined by the relative luminescence method.

Spectral Luminescent Properties and Nature of Electronically Excited States of Sulfaguanidine in Water

Spectral Luminescent Properties and Nature of Electronically Excited States of Sulfaguanidine in Water