Spectrophotometric Studies of the Reaction of Zinc(II) with Some Azo‐Triazol Compounds and Its Application to the Spectrophotometric Determination of Microamounts of Zinc(II)

Abstract

A new, simple, and sensitive quantitative spectrophotometric method for the rapid determination of zinc(II) using six azo compounds based on 3‐amino‐1,2,4‐triazole, namely {3‐(2,4‐dihydroxy‐1‐phenylazo)‐1,2,4‐triazole) (I), 3‐(2‐hydroxy‐5‐methyl‐1‐phenylazo)‐1,2,4‐triazole) (II), 3‐(2‐hydroxy‐5‐acetyl‐1‐phenylazo)‐1,2,4‐triazole) (III), 3‐(2‐hydroxy‐5‐ethylcarboxylate‐1‐phenylazo)‐1,2,4‐triazole) (IV), 3‐(2‐hydroxy‐5‐formyl‐1‐phenylazo)‐1,2,4‐triazole) (V), and 3‐(2‐hydroxy‐5‐bromo‐1‐phenylazo)‐1,2,4‐triazole) (VI), has been developed for use in aqueous media containing 40% (v/v) methanol. Linear calibration graphs are obtained up to 2.6, 5.9, 5.2, 5.2, 8.2 and 9.0 µg mL^?1 using ligands I, II, III, IV, V, and VI, respectively. Absorption maxima, molar absorptivities, and Sandell's sensitivities of 1:2 (M:L) complexes were found to be 490, 530, 505, 520, 550, and 510 nm, 4.86×10⁴, 2.10×10⁴, 1.26×10⁴, 0.10×10⁴, 0.19×10⁴, and 0.29×10⁴ L mol^?1 cm^?1, and 0.0014, 0.0031, 0.0052, 0.0662, 0.0348, and 0.0225 µg cm^?1 for ligands I, II, III, IV, V, and VI, respectively. Using the masking agents, the color reactions are free from interference by more than 30 ions investigated. The method has been applied to the spectrophotometric determination of trace amounts of zinc in pharmaceutical formulations and human hair samples. A study of some zinc solid complexes showed that chelation takes place through one nitrogen atom of the azo group and proton displacement from the hydroxyl group.     

Luminescence Properties of Poly(3-Methoxythiophene)—Bithiophene Composite Oligomers

The electronic absorption and fluorescence spectra of electrosynthesized poly(3-methoxythiophene)— bithiophene (PMOT-BT) composite oligomers were studied in organic solution (DMSO) and/or in the solid state on ITO plates. Different spectral properties (absorption and fluorescence maximum wavelengths, fluorescence quantum yields, etc.) were found to depend on the bithiophene initial concentration used during electrosynthesis and, subsequently, on the film composition and oligomer chain length.     

A Realization of the W_(1+∞) Algebra and Its n-Algebra

We consider a realization of the W_(1+∞) algebra and investigate its n-algebra, which is different from the n-algebra of Zhang et al. [2016 arXiv:1606.07570 v2] It is found that the generators W_m~s with any fixed superindex s ≥ 1 yield the null sub-2 s-algebra. The nontrivial sub-4-algebra and Virasoro-Witt 3-algebra are presented. Moreover,we extend the generators to the multi-variables case. These generators also yield the W_(1+∞) algebra and null n-algebras.     

The Dependence of the Luminescence Intensity of Lanthanide Complexes with β-Diketones on the Ligand Form

The influence of -diketone forms on the luminescence intensity of lanthanide compounds in a series of ligands, acetylacetone (trifluoroacetylacetone, benzoylacetone)—their unsaturated analogues (monomeric form)—copolymers of the latter with styrene (methylmethacrylate), was studied. Lanthanides in compounds with copolymers have been established to demonstrate the brightest luminescence. It was found that its intensity depends not only on the character of the substituent (CH₃, CF₃, C₆H₅) in the -diketone molecule, but also on the distance between the -diketone fragments in the copolymer. Reasons explaining the high intensity of luminescence in lanthanide–copolymer compounds are considered.     

Luminescence of ion-irradiated α-quartz

Optical functionality of materials used in devices is the basis of modern photonics. It depends on selected photoactive impurities or low-dimensional structures, which can be tailored by ion implantation. The present survey covers cathode-luminescence spectroscopy performed after Ge, Ba, Na, Rb and Cs ion implantation in α-quartz, in connection with dynamic, laser-induced and chemical epitaxy of the surface layers amorphized during the ion irradiation. The correlations, which emerged for various luminescence bands, ion species and thermal processing methods, allows one to classify the bands into ion-specific and intrinsic ones. The microstructural properties measured by ion beam analysis and transmission electron microscopy will be combined with the luminescence data, and the role of photoactive defects in quartz and nanoparticles of the implants will be discussed. The technologically most attractive case of double Rb/Ge implantation will be highlighted, which combines the achievement of full chemical epitaxy (due to the alkali ions) and a high light output (due to Ge atoms). Finally, some investigations suggested to better understand the interplay between nanostructure and light emission in ion-doped quartz and the enormous potential for photonic application will be outlined.     

Luminescence Characterisation of the Reaction System Histidine–KBrO3–Tb(III)–H2SO4

Chemiluminescence of the system containing Tb(III) ions, histidine and bromate ions in acid solution was studied. The kinetic curves and CL emission spectra of the system were discussed. The emission spectrum of the histidine–Tb(III)–KBrO₃–H₂SO₄ system revealed two emission maxima at ∼490 and 550 nm, characteristic of Tb(III) ions. Values of lifetimes of the Eu(III) excited states in Eu(III)–histidine system have shown that the histidine formed ML and ML₂ complexes in neutral solution and did not make them in acidic environment. On the basis of the results, a possible mechanism of reaction system: histidine–Tb(III)–KBrO₃–H₂SO₄ is presented.     

Variation in the Luminescence Lifetimes of Eucl3·nH2O(N=0,L,2,3,6)

Eu³⁺ ion emission spectra and luminescence lifetimes were investigated for EuCl₃ -nH₂O (n=0,1,2,3,6). Each compound exhibited a characteristic set of emission bands and a specific luminescence lifetime. The number of water molecules and chloride ions coordinated to the Eu³⁺ ion in these materials was estimated from the observed lifetimes, spectroscopic implications, and expected lanthanide coordination numbers. Approximation of the observed luminescence decay constant for each material was possible through the use of arithmetic terms associated with both the complexed water molecules and the complexed chloride ions which make up the inner-coordination sphere of the Eu³⁺ ion.     

The 15~(th) International Conference on Luminescence and Optical Spectroscopy of Condensed Matter(ICL'08)

Lyon, France 7 ~11 July 2008http://ICL08.univ-lyon1.frPLACE OF ICL 08Universitde Lyon, UniversitLUMIERE LYON218, Quai Claude Bernard,69007 LYONINTERNATIONAL PROGRAM COMMITTEEGeorges BOULON, France, ChairAndreis MEIJERINK, The Netherlands, Co-ChairGius…     

The 15~(th) International Conference on Luminescence and Optical Spectroscopy of Condensed Matter (ICL'08)

琦on，httP: Franee 7~11 //ICIDS.一1 1 July univ一lyon 2(X)8 1 .fr PLACE OF ICL，08 Universit‘de场on，Universit乙LUMIERE LYONZ 18，Quai Claude Bernard，69(刃7 LYON ORGANIZERS肠玩ratoire Physieo一Chimie des Mat‘riaux Lumines- CelltS Universi挽de琦on，Uni一ite口aude Bemard Lyonl UMR 5620 CNRS INTERNAT10NAL PROGRAM COMMITTEE Georges BOULON，Franee，Chair Andreis MEUERINK，The Netherlands，Co一Chair GiusepPe BALDACCHINI，Italy Thomas BASHE，Ger…     

Luminescence analysis of blood components in studies of the neuroprotective properties of the drug “Semax” in cerebral ischemia

Luminescence-spectral analysis is used to study the neuroprotective effect of the drug Semax on the level of oxidative stress in cerebral tissues during cerebral ischemia through estimation of the free-radical damage to low density lipoproteins in animal blood serum. It is found that Semax decreases the oxidative stress in cerebral tissues during ischemia by reducing the production of free-radical compounds owing to activation of an inflammation line of protection for the organism. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 1, pp. 131–137, January–February, 2009.     

The 15~(th) International Conference on Luminescence and Optical Spectroscopy of Condensed Matter (ICL'08)

Lyon, France 7 ~11 July 2008 http://ICL08.univ-lyon1.frPLACE OF ICL 08Universit de Lyon, Universit LUMIERE LYON218, Quai Claude Bernard,69007 LYONORGANIZERSLaboratoire Physico-Chimie des Mat啨riaux Lumines-centsUniversit啨de Lyon, Universit啨Claude Bernar…     

The 15~(th) International Conference on Luminescence and Optical Spectroscopy of Condensed Matter (ICL'08)

Lyon,France 7~11 July 2008http://ICL08.univ-lyon1.frPLACE OF ICL 08Universitéde Lyon,UniversitéLUMIERE LYON218,Quai Claude Bernard,69007 LYONORGANIZERSLaboratoire Physico-Chimie des Matériaux Lumines-centsUniversitéde Lyon,UniversitéClaude Bernard Lyon 1UMR 5620 CNRSINTERNATIONAL PROGRAM COMMITTEEGeorges BOULON,France,ChairAndreis MEIJERINK,The Netherlands,Co-ChairGiuseppe BALDACCHINI,ItalyThomas BASHE,GermanySergei BASUN,RussiaD.BI…     

Luminescence with Local Distribution and Its Possible Mechanism in Zinc Oxide Micro-Crystallites

The spatial luminescence distribution hi the ZnO micro-crystallite fihns deposited on silicon substrates by CVD at room tempezature is investigated by the cathedolumineseence （CL） image. It has been observed that the CL image of the samples constitutes a certain pattern. The UV emission pattern projective to the （0001） face of ZnO grains consists of a series of lines nearby the grain boundaries . The included angles between any two adjacent lines are almost 120°. What is more, some luminescent lines form a close hexagon similar to ZnO crystalline structure. Such a local distribution propety shows that the UV emission on as-grown ZnO crystallite should be due to some local defects congregated to {1010} facets of ZnO grain rather than free exciton recombination.     

Gravitational Faraday Rotation of the Earth and Its Possible Test

It is shown that the rotation of the polarization plane of rays induced by a rotating body can be accumulated by means of a long baseline optical cavity. Theoretical analysis shows that the presently proposal experimental scheme is possible to test this gravitational Faraday rotation effect on the Earth, especially including how to effectively suppress the dominant part of the Sagnac effect due to the rotation of the Earth with a reasonable experimental configuration.     

Preparation and Tunable Luminescence Properties of Tb(III)-Doped Zinc–Aluminum Hydrotalcite-Like Compounds

Journal of Applied Spectroscopy - Tb3+-doped Zn–Al (Zn–Al–Tb) hydrotalcites with tunable blue-green emission synthesized by co-precipitation. The compositions and properties of...     

On the occasion of the centennial of the birth of Sergei Nikolaevich Vernov (1910–1982)

Proceedings of the International Conference “Nucleus 2009: Fundamental Problems and Applications of Nuclear Physics, from Cosmos to Nanotechnologies” (LIX International Conference on Nuclear Spectroscopy and Atomic Nuclear Structure)

On the occasion of the centennial of the birth of Sergei Nikolaevich Vernov (1910–1982)     

Surface-Radiative Modes and Longitudinal Excitons in the Spectra of Exciton–Polariton Luminescence

A cascade fiber-optic system that generates pulses of high spectral density by using the effect of nonlinear spectral compression is proposed. It is demonstrated that the shape of the pulse envelope substantially influences the degree of compression of its spectrum. In so doing, maximum compression is achieved for parabolic pulses. The cascade system includes an optical fiber exhibiting normal dispersion that decreases along the fiber length, thereby ensuring that the pulse envelope evolves toward a parabolic shape, along with diffraction gratings and a fiber spectral compressor. Based on computer simulation, we determined parameters of cascade elements leading to maximum spectral density of radiation originating from a subpicosecond laser pulse of medium energy.     

Luminescence of GaN Layers Grown on GaAs Substrates by the Method of Radical‐Beam Epitaxy

We have investigated the properties of GaN films obtained by the method of radicalbeam gettering epitaxy. At room temperature the photoluminescence spectra display a weak peak at 3.37 eV, with the fundamental radiation band being located in the range 1.7–2.0 eV. At the temperature 4.2 K, the band with an energy of 3.47 eV is present. The donoracceptor transition with a maximum at 3.26 eV and its phonon repetition dominate in the spectrum. A wide yellow band with a maximum at 2.10 eV and a weak peak at 2.88 eV are also observed. It has been established by Auger electron spectroscopy that gallium and nitrogen are the basic elements that enter into the composition of the film. Xray structural investigations have shown that the films possess a hexagonal structure.     

Luminescence behaviour and Raman characterization of dendritic agate in the Dereyalak village (Eski?ehir), Turkey

Results are presented for the cathodoluminescence (CL), X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and simultaneously two thermal analyses of (DTA/TGA) spectroscopy of dendritic agate which occurs in the Pliocene polymictic conglomerates of the Höyüklü Formation, North West of the Dereyalak village (Eskisehir, Turkey). Micro-Raman measurements were performed on dendritic agate and then strong quartz and moganite peaks were identified at 465 and 501 cm⁻¹, respectively. Thermal analysis shows the loss of water and hydroxyl units occurs in 2 distinct stages; at 796 and 808 °C. Spatially resolved CL results at room temperature were recorded for chosen 3 different areas. Grey area (100% SiO₂) displays the lowest CL emission. Brown area (99.7% SiO₂ and 0.3% Fe₂O₃) contains exsolved non-detected ironed phases such as goethite-lepidochrocite to explain the brown colour and the iron point substitutional defects attributed to the 643 nm CL emission. White outer (98.7% SiO₂ and 1.3% Al₂O₃) would be strongly disordered as observed in the “amorphous” Raman spectrum containing as inferred from the spectrum CL on the outer areas, particularly non-bridging oxygen hole centres (NBOHC) (317 nm) and [AlO₄]°/H⁺ (380 nm) centres produced by large amounts of aluminium in the lattice (1.33% Al₂O₃). When it comes to collect the data in the time resolved CL spectrum, at least three broad emission bands were detected in: a green band of low intensity at about 496 nm, intense orange band at about 600 nm, and a red band at 670 nm. The CL emission at 670 nm shows some relationships between the hydroxyl or alkali content and the abundance of O₂ (super 3-) centres and E′₁ centres. Another conspicuous observed feature in the CL spectra of agates is the existence of an orange emission band centred at around 600 nm. The predominance of the yellow CL emission band and the high concentration of E′₁ centres are typical for agates formed by acidic volcanism processes.