Previously calculated multidimensional potential energy surfaces of the methanol monomer and dimer, water dimer, malonaldehyde, formic acid dimer, free pyridine N-oxide/trichloroacetic acid complex, complex in acetonitrile and protonated water dimer were analyzed. Based on the behavior of calculated multidimensional potential energy surfaces, corresponding harmonic potential energy surfaces were constructed for the series of clusters and complexes with hydrogen bond of different strength near the global minimum. This enables to introduce an obvious anharmonicity parameter for the calculated potential energy surfaces. Dependence of the anharmonicity parameter on the size of the analyzed area near the energy minimum, on the number of points, where the energy comparison were implemented, and on the dimensionality of the solved vibrational problem was analyzed. Calculations of the anharmonicity parameter of the potential energy surfaces for complexes with strong, medium and weak hydrogen bonds were performed at the unified conditions. The obtained values of the anharmonicity parameter were compared with the values of the corresponding diagonal anharmonicity constants for the stretching vibrations of the bridging proton, and also with the length of the hydrogen bridges.

We used 1-methyl-4-(2-pyren-1-yl-vinyl)-pyridinium iodide, a pyridinium derivative fluorescent dye, as a solvatochromic and solvatofluorchromic probe to straightforwardly characterize the solvent polarity. The absorption and fluorescence spectra of 1-methyl-4-(2-pyren-1-yl-vinyl)-pyridinium iodide show a dramatic dependence on solvent polarities in the high-polar range. It exhibits two absorption peaks around 400 and 450 nm, as well as an emission maximum at 605 nm. Several parameters (ratio of the two absorption peaks, wavelength of the principal absorption peak, fluorescence signal, and ratio of fluorescence intensities excited at the two absorption bands) are linearly dependent on the solvent polarity-polarizability values. Strong correlations have been also obtained with the P¢ and P_y polarity scales with small deviations. Moreover, 1-methyl-4-(2-pyren-1-yl-vinyl)-pyridinium iodide possesses high fluorescence quantum yield (0.38-0.54) and relatively long lifetime (2.2-2.6 ns) in all studied organic solvents. All these optical properties make 1-methyl-4-(2-pyren-1-yl-vinyl)-pyridinium iodide a favorable probe to quantitatively characterize the solvent polarities in the high-polar range through a multiparametric approach.

The structural and optical properties of Ba_{1- x} Sm_2x/3ZrO₃ (x = 0.02, 0.04, 0.06, 0.08, 0.10) ceramics prepared by the solid state reaction method are considered. The x-ray diffraction data confirm the cubic perovskite phase of all the compositions with space group Pm ` 3m. The effect of Sm³⁺ substitution on the optical band gap and photoluminescence properties of barium zirconate are discussed. The optical band gap decreases from 3.43 to 2.98 eV with increasing Sm³⁺ content. The Urbach energy has been found to increase with rise in concentration of dopant species. The photoluminescence spectra show an intense violet-blue emission characteristic of the barium zirconate perovskite. Visible emission due to intra-4f transitions of Sm³⁺ ions from⁴G_5/2 higher excited state to⁶H_j (j = 5/2, 7/2, 9/2 etc) ground states has been observed in the range of 550-700 nm.

Spectral-kinetic characteristics of annihilation delayed fluorescence (ADF) of indole and its derivatives (5-methylindole, N-methylindole) in aqueous solution at room temperature were measured. ADF spectra of indole and 5-methylindole consist of two bands with wavelength maximum at 350 and 425 nm for indole and 350 and 390 nm for 5-methylindole. The shortwave band is due to the ADF of monomers and coincides with the spectrum of the fast fluorescence. The longwave band is attributed to ADF of excimers, excited singlet states of which are populated due to annihilation of triplet excimers. Triplet states of excimers are formed due to collisions of molecules in the triplet and ground states. ADF spectrum of 5-methylindole consists of only shortwave band of ADF of monomers with the wavelength maximum at 350 nm. Triplet state lifetimes of monomers and excimers were estimated from the ADF kinetics.

The radiative deactivation of lowest singlet and triplet excited sates for the family of the free base and Zn²⁺ -complexes of water soluble 5,10,15,20-tetrakis-(4-sulphonatophenyl)-porphyrin (Н₂ТSPP), 5,10,15,20-tetrakis-(4-N-alkylpyridyl)-porphyrin (Н₂Т4АlkPyP), 5,10,15,20-tetrakis-(3-N-alkylpyridyl)-porphyrin (Н₂Т3AlkPyP) has been studied in solution at temperatures 77 and 293 K. The quantum yields of fluorescence and phosphorescence was found to have small but detectable differences for the derivatives of the same porphyrin ligand with different counter ions of ionized aryl substituents. It was shown that these differences were due to the spin-orbit coupling effect, variations in electron donating/accepting properties of peripheral substituents, which result in the electronic levels energy changes in the porphyrin-counter ion system.

The spectral and energy characteristics of the generation for three laser dyes in the red spectral region 650-720 nm in preliminarily annealed xerogel SiO₂ matrices under laser excitation l_p = 588 nm in a nonselective resonator were measured and analyzed. The specific output laser energy for two of them (for LK678 and Ox170) in the matrices was 10-13 % higher than in methanol. The NBA dye in the matrix generates two laser radiation bands in the 700-720 nm region with pumping E_p ³ 80 mJ, while in methanol its generation threshold exceeded the maximum pumping energy of 140 mJ and NBA generation was not achieved. The laser spectra of the studied matrices in a nonselective cavity were shifted to the red region from the fluorescence maximum by ~1000 cm^{- 1} . Such a shift can improve the characteristics of biosensors based on these matrices.

A comparative study of eye-safe extracavity KGW Raman lasers that convert multimode radiation from Nd:KGW lasers operating on⁴F_3/2-⁴I_11/2 and⁴F_3/2-⁴I_13/ transitions into the third Stokes component at l = 1500 nm and the first Stokes component at l = 1507 or 1538 nm, respectively, was carried out. For the same sizes of laser and Raman elements, Raman laser emitting the third Stokes component provides higher power and energy of the pulse (~14.2 mJ) and smaller divergence of the Stokes beam (~9.4 mrad) at lower pump energy of Nd:KGW laser (~6.7 J). At the pump pulse energy of 29-34 mJ, all Raman lasers have the same optical efficiency reaching 36 %. However, in terms of the electrical energy delivered to the flashlamp, the total efficiency of the Raman laser of the third Stokes component is »1.7 times larger. The duration of Raman pulses is comparable to that of pump pulses and is ~20 ns for the first Stokes components. The pulse of the third Stokes component is shorter by a factor of 2.5-3. Because of different pump levels and different strength of thermo-optical distortions of Nd:KGW laser elements, the energy density distribution for the beams of the first Stokes component is elliptical, while it is almost circular for the beam the of the third Stokes component. The possibility of simultaneous lasing at wavelengths of 1507 and 1538 nm in parallel and orthogonal polarizations of Stokes waves is shown.

Raman spectroscopy was used to study the structural properties of graphene synthesized by the chemical vapor deposition method using decane (C₁₀H₂₂) as a precursor at various hydrogen concentrations. Reduction of the carrier gas flow from 150 cm³/min to zero leads to a change in the average spacing between defects from 53 to 212 nm, average grain size from 87 to 798 nm, and to violation of the graphene layer continuity. The obtained dependences can be used to control the defectiveness, homogeneity and continuity of the graphene layer coating during the synthesis by this method.

Data on observation of simultaneous up-conversion on the trace erbium and thulium ions in KGd(WO₄)₂ crystal excited by IR radiation with the wavelength near 806 nm are presented. The change of excitation schemes with increase of pumping level and participation of crystal matrix in energy transfer from erbium to thulium ions are discussed.

Raman spectroscopy was used to study the structure of graphene that was synthesized from methane and transferred to a SiO₂/Si substrate. The synthesis was carried out by chemical vapor deposition at atmospheric pressure. Various methods of the graphene transfer and the polymer removal were used. It is found for the samples under study that the dependence of the 2D peak position on the position of the G peak is well described by linear functions with slope ~2.2 that suggests the existence of a biaxial stress in graphene. A change of doping in the samples was discovered.

Highly purified detonation nanodiamond powders (DND) were investigated by the method of electron paramagnetic resonance (EPR) at room temperature. Upon registration of EPR signal with a g-factor of 2.00247 and a linewidth of 0.890 mT in the mode of automatic frequency control, a change in the shape of the EPR signal of the DND powders, caused by the formation of an anisotropic electroconductive structure, was detected. The electrical conductivity of the DND sample was manifested in the Dyson form of the EPR line (a strongly asymmetric signal with a g-factor of 2.00146 and a linewidth of 0.281 mT) on the background of a sharp shifted zero level at the moment of resonant absorption and in a decrease in the quality factor due to non-resonant microwave absorption. The observed effect can be explained by the transition of the DND powder from the dielectric state to the state with metallic conductivity caused by the ordering of the spins in the definite direction.

Composite nickel-carbon nanoparticles were synthesized by electric discharge in liquid. The synthesis was carried out in water and ethanol under various discharge conditions, including blowing the discharge gap with argon. Discharge in water was carried out between the graphite and nickel electrodes. In the case of synthesis in ethanol, two nickel electrodes were used with the liquid, acting as the carbon supplier. The size of the particles obtained, their composition, and the operating speed depend on the type of working fluid and the time of synthesis. It is also shown that the particle production rate in water is higher than in ethanol, and the blowing of the discharge gap by argon reduces this rate by two or three times.

The use of the linear combination of the Lorentz function and its square provides the better description of Mössbauer spectra obtained with the use of resonant detector. For solid solutions of beryllium with 0.09-0.8 mass.% iron, the results of the mathematical fit and the description of the spectra were obtained. The fine structure parameters of the solid solutions coincide with the literature data. Features of use of a new method are discussed. This method could be used for the fast processing of experimental spectra.

The effect of salinity on the conformation of proteins of four salt-tolerant M₂ generation mutants of soybean plants (S04-05/150-2, S04-05/150-8, S04-05/150-106, and S04-05/150-114) was investigated using Fourier transform infrared (FTIR) spectroscopy. Salinity is one of the important abiotic stress factors that limits growth and productivity of plants. The mutants belonging to the M₂ generation were determined as tolerant to 90 mM NaCl. The relative contents of a-helix, b-sheet, turn, and irregular conformations for the soybean protein isolates were determined depending on the analysis of the amide I region. The comparison of the secondary structures of soybean proteins of the mutants with those of the control group indicated that the a-helix structure percentage was diminished while b-turn and disordered structures were increased as a result of the salt stress.

The composition of inorganic and organic parts of gallstones is investigated by the methods of X-ray phase analysis and IR spectroscopy. It is shown that cholesterol, bilirubin, calcium bilirubinate, calcium carbonate, and calcium hydrogen phosphate are the parts of gallstones. Meanwhile, cholesterol is prevailing. A layered separation of the gallstone as well as a separation of its inorganic part by the annealing are carried out. It is established that the inorganic compounds predominate in the outer layer of the gallstone, which is related to the mechanism of its formation. The composition of the inorganic part includes calcium carbonate of two modifications: calcite and waterite.

Different optical methods for the analysis of the process of temoporfin photosensitizer distribution between supramolecular nanosized inclusion complexes based on b-cyclodextrins and blood serum proteins were considered. We compared the application possibilities of the methods based on induced circular dichroism, fluorescence anisotropy, and variability of the fluorescence excitation spectra shape of the photosensitizer with such traditional methods as gel-chromatography and ultracentrifugation. The possibility of using the photosensitizer optical characteristics for the analysis of both equilibrium and kinetic processes of photosensitizer distribution in blood was shown. The main advantages and limitations of the studied approaches in in vitro experiments were described.

The differences between a-type and b-type chlorophylls have been determined by the spectrophotometric method for the Hypogymnia physodes samples from different economic areas and natural complexes of the Tver region. It shows that the photosynthetic system of lichens has a high plasticity. The level of the b-type chlorophyll relates to the adaptation to the features of ecological niches in different phytocoenosis. The change of the a-type chlorophyll concentration provides a necessary compensatory response in the conditions of technogenic stress. The content of 15 metals (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Ti, V, Zn) were determined by ICP-AES analysis in the Hypogymnia physodes samples. Among them, iron, aluminum, and titanium are the most widespread. The significant correlation between the chlorophyll concentration and the metal content has been revealed.

Mushroom tyrosinase (MT) was considered a good model for studying the inhibition, activation, and mutation of tyrosinase as the key enzyme of melanogenesis. In the present study, the activity, structure, reduction, and stability of native and modified enzymes were investigated after the modification of MT carboxylic residues by the Woodward reagent K (WRK). The relative activity of the sole enzyme was reduced from 100 to 77.9, 53.8, 39.4, and 26.4% after its modification by 2.5, 5, 25, and 50 ratios of [WRK]/[MT], respectively. The T_m values were calculated from thermal denaturation curves at 61.2, 60.1, 58.3, 53.9, and 45.5°C for the sole and modified enzymes. The reduction of the ∆G_H2O values for the modified enzyme in chemical denaturation indicated instability. A structural study by CD and intrinsic fluorescence technique revealed the fluctuation of the secondary and tertiary structures of MT.

Samples of green coffee beans originating from five different countries were ground and analyzed using FTIR spectra in the region of 600-4000 cm^{- 1} . Successful discrimination of each coffee type based on their origin was achieved applying a PCA algorithm on the obtained IR spectra for all samples. PCA loading plots show that the IR bands at 2850, 2920, and 1745 cm^{- 1} corresponding to the symmetric, and antisymmetric vibrations of CH₂ and the stretching vibration of C=O bond in ester, respectively, are the most significant peaks in distinguishing the origin of the above coffee samples.

The new photosensitive polymeric film composites based on non-photoconducting polyvinylbutyral doped with heterometallic complexes Cu/M (M=Ca, Sr) are synthesized and investigated. These composites possess photoconducting and photovoltaic properties and electronic type of photoconductivity. Photocurrent is larger in the composites with complexes having less distance between the nearest metallic copper centers. This phenomenon is attributed to a larger probability of electron transfer between these centers.

A multifunctional IR parametric laser complex for remote detection and identification of atmospheric gases, contained in small amounts, as well as explosive and chemically aggressive substances, was developed and tested. Calculations and experimental studies on the remote determination of the spectroscopic parameters of the most known explosives, including TNT, RDX, PETN, were carried out. The possibility of high-sensitivity (~ 1 ppm) detection of the substances with the help of a multifunctional IR OPO by the method of differential absorption and scattering is shown.

The present work is devoted to the development of a rapid method for analyzing lignin in paper using IR reflectance spectra from its surface. To develop the method, the IR absorption and reflectance spectra of model paper samples made from hardwood and softwood fibers with different lignin content were analyzed. A comparison of the intensity of the lignin absorption band at 1510 cm^{- 1} in the absorption spectra after the Kubelka-Munk transformation of the reflectance spectra of the paper and chemical data on the lignin content in the fibers showed a good correlation. The analytical relationship between the lignin content in the paper fibers and the intensity of the lignin absorption band was used to estimate the lignin concentration in the samples of Russian stamping paper of the 19th century using their IR reflectance spectra. The cellulose structure parameter, estimated from the paper reflectance spectra, showed that the sheets containing lignin (5-16%) consisted entirely of wood fibers, and they were supplemented with kaolin.

The surface structure and cathodoluminescence (CL) spectra of thin films of Y₂O₃:Eu obtained by RF sputtering were investigated by varying the activator concentration in the range of 1.0-7.5 % by mole. Based on the shape of the CL spectra at different concentrations of the activator, the possibility of creating irregular solutions of yttrium and europium oxides and structural features of the small and large crystallites forming the Y₂O₃:Eu film were shown. The critical distance for the interaction between Eu³⁺ ions in nodes with C₂ and C_3i point symmetry was estimated and a mechanism of the energy migration between these centers was proposed.

The Х-ray phase analysis of the general mineralogical composition of core samples from one of the fields in Western Siberia was performed. The electronic absorption spectra of the clay core samples with an introduced indicator were studied. The estimation of the speed and availability of the application of two methods in petrophysical laboratories during the preparation of samples for standard and special studies is given.

The measurement of the moisture content of dehydrated residues by rapid methods is an actual problem, the solution of which will increase the efficiency of treatment facilities and optimize the process of applying flocculants. As a result of the research, the possibility to determine the moisture content of dehydrated residues by a meter operating on the principle of receiving reflected radiation in the infrared wavelength range has been experimentally confirmed. Based on the analysis of the obtained diffuse reflectance spectrum of the dehydrated residue in the wavelength range of 1.0-2.7 μm, the most suitable interference filters were selected. Calibration equations were constructed for each filter set and a comparative analysis was performed. The best agreement with the laboratory measurements was obtained for the measuring filter with the transmittance maximum of 1.19 μm and the reference filter with the maximum at 1.3 μm.

Glutaraldehyde cross-linked magnetic chitosan nanoparticles were synthesized and used as an adsorbent for the dispersive solid-phase extraction of palladium in active pharmaceutical ingredients (APIs) prior to analysis by a flame atomic absorption spectrophotometer. FT-IR, X-ray diffraction, and TEM were used to characterize the adsorbent. Various parameters of experimental performance, such as adsorbent amount, pH, adsorption time, desorption solutions, coexisting ions, and adsorbent reusability, were investigated and optimized. Under the optimized conditions, good linearity was achieved in the 5.0-500 μg/L concentration range, with correlation coefficients of 0.9989. The limit of detection is 2.8 μg/L and the recoveries of spiked samples ranged from 91.7 to 97.6%. It was confirmed that the GMCNs nanocomposite was a promising adsorbing material for extraction and preconcentration of Pd in APIs.

A new ligand (L), N,N′-bis(2-hydroxybenzyl)-1,2-diaminoethane, was synthesized and characterized. The sensing behavior of L toward various metal ions was investigated by spectrofluorometric and UV-Vis spectrophotometric methods. The sensor displayed selective and sensitive recognition toward Fe³⁺ and Fe²⁺ in acetonitrile. The fluorescence of L was quenched mainly by Fe³⁺ , and a considerable enhancement of fluorescence was observed in the presence of Zn²⁺ . Using multivariate hard modeling and stoichiometry, the concentration, spectral profiles, and formation constants of the studied complexes were calculated.

The Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectra of 2,6-dibromo-3-chloro-4-fluoroaniline in the solid phase were recorded and analyzed. Quantum chemical calculations of the optimized molecular structure, energies, nonlinear optical (NLO) analysis, molecular surfaces, and vibrational analysis of this substance were performed. The obtained results on the geometric structure and vibrational frequencies were compared with the observed data. The calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies also confirm that charge transfer occurs within the molecule. The detailed vibrational assignments were performed using the HF and DFT calculations, and the potential energy distribution (PED) was obtained by the vibrational energy distribution analysis (VEDA4) program. Finally, the effects of the amino, bromo, chloro, and fluoro substituents on the vibrational frequencies were investigated.

A rapid detection of heavy metals in soil was presented by the metal-assisted gas plasma method using specific characteristics of a pulsed, transversely excited atmospheric (TEA) CO₂ laser. The soil particles were placed in a hole made of acrylic plate. The sample was covered by a to prevent the soil particles from being blown off. The mesh also functioned to initiate a luminous plasma. When a TEA CO₂ laser (1500 mJ, 200 ns) was focused on the soil sample, passing through the metal mesh, some of the laser energy was used to generate the gas plasma on the mesh surface, and the remaining laser energy was employed to ablate the soil particles. The fine, ablated soil particles moved into the gas plasma region to be dissociated and excited. Using this technique, analysis can be made with reduced sample pretreatment, and therefore a rapid analysis can be performed efficiently. The results proved that the signal to noise ratio (S/N) of the emission spectral lines is much better for the case of the present method (mesh method) compared to the case of standard laser-induced breakdown spectroscopy using the pellet method. Rapid detection of heavy metal elements in soil has been successfully carried out. The detection limits of Cu and Hg in soil were estimated to be 3 and 10 mg/kg, respectively. The present method has good potential for rapid and sensitive detection of heavy metals in soil samples.

Two simple and sensitive extraction-free spectrophotometric methods are described for the determination of flunarizine dihydrochloride. The methods are based on the ion-pair complex formation between the nitrogenous compound flunarizine (FNZ), converted from flunarizine dihydrochloride (FNH), and the acidic dye phenol red (PR), in which experimental variables were circumvented. The first method (method A) is based on the formation of a yellow-colored ion-pair complex (1:1 drug:dye) between FNZ and PR in chloroform, which is measured at 415 nm. In the second method (method B), the formed drug-dye ion-pair complex is treated with ethanolic potassium hydroxide in an ethanolic medium, and the resulting base form of the dye is measured at 580 nm. The stoichiometry of the formed ion-pair complex between the drug and dye (1:1) is determined by Job’s continuous variations method, and the stability constant of the complex is also calculated. These methods quantify FNZ over the concentration ranges 5.0-70.0 in method A and 0.5-7.0 µg/mL in method B. The calculated molar absorptivities are 6.17´10³ and 5.5´10⁴ L/mol´cm^-1 for method A and method B, respectively, with corresponding Sandell sensitivity values of 0.0655 and 0.0074 µg/cm². The methods are applied to the determination of FNZ in pure drug and human urine.

A handheld RGB camera was developed to monitor the in vivo distribution of porphyrin-based photosensitizer (PS) hematoporphyrin monomethyl ether (HMME) in blood vessels during photodynamic therapy (PDT). The focal length, f-number, International Standardization Organization (ISO) sensitivity, and shutter speed of the camera were optimized for the solution sample with various HMME concentrations. After the parameter optimization, it was found that the red intensity value of the fluorescence image was linearly related to the fluorescence intensity under investigated conditions. The RGB camera was then used to monitor the in vivo distribution of HMME in blood vessels in a skin-fold window chamber model. The red intensity value of the recorded RGB fluorescence image was found to be linearly correlated to HMME concentrations in the range 0-24 μM. Significant differences in the red to green intensity ratios were observed between the blood vessels and the surrounding tissue.

Elemental evaluations in scanty powdered material have been made using energy dispersive X-ray fluorescence (EDXRF) measurements, for which formulations along with specific procedure for sample target preparation have been developed. Fractional amount evaluation involves an itinerary of steps; (i) collection of elemental characteristic X-ray counts in EDXRF spectra recorded with different weights of material, (ii) search for linearity between X-ray counts and material weights, (iii) calculation of elemental fractions from the linear fit, and (iv) again linear fitting of calculated fractions with sample weights and its extrapolation to zero weight. Thus, elemental fractions at zero weight are free from material self absorption effects for incident and emitted photons. The analytical procedure after its verification with known synthetic samples of macro-nutrients, potassium and calcium, was used for wheat plant/soil samples obtained from a pot experiment.

Methods of extraction-spectrophotometric determination of tris(2-chloroethyl)amine using nine acid dyes from the groups of sulfonephthaleins, sulfonated anthraquinones, and azo dyes have been developed. These procedures are based on the formation of the ion associates of the reactants and their extraction into chloroform. The conditions of the determination were optimized to determine the optimal pH for extraction from the water phase, the optimal excess of the dye, and the time needed for the extraction. The limits of detection and determination, the molar absorptivities of ion associates, extraction efficiency, distribution ratio, and conditional extraction constants for the separate procedures of determination were calculated. Of the studied acid dyes, the most suitable agents for determining the analyte were bromothymol blue and Acid Blue 129. These procedures are relatively undemanding in terms of time and instruments required and can be applied in field analysis of nitrogen mustards.

Thin films of nickel doped zinc oxide (Zn_{1- x} Ni_xO) show redshift in the optical band gap and in the near band edge (NBE) emission of the photoluminescence spectra. The Zn_{1- x} Ni_xO thin films obtained by sol gel spin coating method show narrowing of the band gap from 3.23 to 3.00 eV as the concentration of nickel is increased from x = 0.00 to x = 0.06. All the Zn_{1- x} Ni_xO thin films have hexagonal wurtzite structure and show a decrease of 119 meV in the NBE emission as the dopant concentration is increased. X-ray diffraction spectroscopy (XRD) confirms the formation of ZnO in the films; Fourier transform infrared spectroscopy (FTIR) reaffirms this. Energy dispersive analysis (EDX) also ascertains the presence of Ni in the films and calculates the amount of dopant present in the films. Scanning electron microscopy (SEM) shows that all the Ni doped ZnO thin films possess granular surface morphology.