The work is devoted to the description of the integral intensity of molecular light scattering by the surface of glasses. The main attention is focused on the manifestations of the quasi-static distortions of the glass surface.

It was shown in numerical simulation that when a sequence of periodic electron pulses is going through a double barrier system there exists a range of parameters where chaotic regime, characterized by a strange attractor in a phase place takes place. It has been established that the action of a low intensity ac field with the frequency multiple to the frequency of incoming periodic pulses results in stabilizing of the unstable regime. The intensity threshold of the effective influence of the electromagnetic field has been found.

A synergetic conception of plastic deformation where the cooperation between defects results to a phase transition is presented. A reconstruction picture of defect structure in the presence of fluctuations in extended systems is considered. We show that the system undergoes a reentrant phase transitions of first and second order with an increase in an intensity of fluctuations, diffusion constant or external tension due to existence of correlation effects of fluctuations.

Two-phonon Raman spectra of ciystals ZnP₂, CdP₂, and Te0₂ were measured. All these ciystals are gyrotropic and belong to P4₁2₁2 or P4₃2₁2 enantiomorphous space symmetry groups. The selection rules for overtones and combined tones at high symmetry points Γ, Z, A, M, X and R of Brillouin zone were obtained using irreducible projective representations of wave vector symmetry groups Zero slope points were identified too. It was determined lines, which correspond to overtones of point Γ and vibrations on boundary Brillouin zone.

Electronic spectra of promising materials for rechargeable lithium batteries, LiC₆ and LiMn₂O₄, have been studied. Theoretical calculations in combination with experiments for the π*0 and σ* x-ray absorption edges are reported for the pure graphite and the graphite intercalation compound, LiC₆. The anisotropy of the absorption spectra is due to the difference in the optical matrix elements for two different polarizations, which is a result of the anisotropic crystallographic and electronic properties of LiC₆. Theory and experiment agree well for the rr and a resonances. By comparing calculations which include the effect of the core hole with similar calculations which do not, we conclude that is x-ray absorption in LiC₆ is partly associated with an excitonic effect. The electronic structure and optical absorption spectrum of LiMn₂0₄ spinel has been calculated and compared with available experimental data. The calculated absorption coefficient appeared to be in agreement with experiment, and the features of the absorption are associated with transitions between the exchange and crystal-field split t_2g and e_g d-bands of manganese in LiMn₂O₄ spinel.

The Green functions method is applied to calculate the attenuation and energy shift of exciton in ionic crystals with the account for LO-phonon dispersion. In one-phonon approximation for weak coupling an analytical expression is obtained, which allows to study this problem depending on both the frequency interval and temperature of crystal. The TlCl and AgBr crystals were chosen as the models for illustrations.

For the first time it is shown, that the correlation in changes of electroluminescence spectrum and a threshold of origin of an acoustic emission in epitaxial lightdiode n⁺-n-p-structures GaP_0.85As_0.15 takes place. It is shown, that the density of a direct current of diode determines intensity of discrete acoustic emission, detrusion and redistribution of intensity in maximums of an electroluminescence spectrum, velocity and quantity of a degradation of emissive power.

Characteristic scattering band in the spectral region of 280-380 nm with the maximum of 300-310 nm is observed in the spectra of diffuse scattering for rutile, contrary to anatase sample. Spectral parameters of this band depend on the treatment temperature. Doping of Ti0₂ samples with Cu, Fe, Co, Cr atoms does not affect the spectral position of the band wing in their diffuse scattering. Luminescence spectra of rutile have only short-wavelength components. Anatase has both fluorescence and phosphorescence at T=4.2 K. At room temperature there is no luminescence detected. Cation-doped anatase does not luminescence at all studied temperatures. Their absorption spectra have a new band in the region of 325-405 nm, which spectral parameters depend on the type ofdoping cation.

The luminescence excitation spectra of europium β-diketonates, aromatic carboxylates, europium nitrates with sulfoxides are analysed. Some processes of transfer and degradation of the excitation energy, which can change the luminance of europium materials, are discussed. Variation of the relative contribution of two inequivalent ligands to the luminescence excitation of europium β-diketonates with heterocyclic diimines upon modification of ligand radicals was investigated. The participation of the ligand-metal charge transfer states both in degradation of the excitation energy and in enhancement of Eu³⁺ luminescence excitation was analysed. Decrease of the ligand-metal charge transfer at introduction of the nitro-groups in the ligand aromatic ring, which sensitizes the Eu³⁺ luminescence, was revealed. The blocking influence of methylene and oxymethylene bridges on the efficiency of the europium luminescence excitation was considered. It was demonstrated, that the donor-acceptor ability of radicals -(CH₂)_nCH₃ and steric factor effect the Eu³⁺ electronic transitions and vibronic interaction.

Within the framework of the traditional Elliott-Toyozawa theory the investigation of absorption spectra of p-GaSe crystals pure, doped and intercalated with manganese impurity made in a wide temperature region (4.5-300K). It is shown that presence in p-GaSe of 2D hole gas localized in quantum wells (QW) that are degenerate with excitons in the momentum space leads to suppression of the oscillator strength of exciton transition for ground, as well as excited, states. It was found that growth of temperature in p-GaSe results in holes redistribution to the higher energy states. This appears as consecutive (from the ground to excited states) suppression of and re-establishment of the integral characteristics of exciton absorption bands. Data of temperature population of 2D hole gas in QW are well explain by Maxwell distribution. Slight differences that appear in temperature dependencies of exciton absorption spectra ofp-GaSe crystals pure, doped and intercalated by manganese impurity are attributed with different depth of QW and location of Fermi level in these crystals.

For the air-ZnO-Si0₂ system (d_ZnO ~0.1-10μ, 400-600 cm^-1 spectral region) we show that there exist three branches of surface polaritons (~420-430, 470-520 and 520-570 cm^-1), the first of them being weak for all d_ZnO. For model medium instead of Si0₂, one of two SP branches which one has for ZnO film in air gradually transforms to two branches. The calculations predict wave-guide branches in both p- and s-polarizations below 420 cm^-1. For the air-Ge-BeO system (dZnGe ~0.1-10μm, 600-1200 cm^-1), deposition of Ge allows one to move the SP absorption away from the frequency of CO₂ laser (960 cm^-1).

Electroluminescent (EL) properties of planar light-emitting nanocomposite structures based on gold island films and semiconducting organic polymers poly(p-pheny!enevinylene) (PPV) and aluminum oxyquinoline (the aluminium (III) 8-hydroxyquinoline complex, Alq3) were studied in 400-600 nm spectral range at room temperature. The chemical composition and structureof vacuum deposited PPV and Alq3 films were determined by IR spectroscopy. According to the obtained data, chemical composition of the deposited A1q3 films corresponds to the initial A1q3. The PPV film is formed of oligomers with smaller molecular weight, which are generated in the course of thermal evaporation in vacuum due to decomposition of initial polymer. It was shown that EL spectra of the nanocomposites consist of two bands, one of them being typical of organic molecules, whereas the second one is related to the luminescence of the island film. Therefore, the obtained planar nanocomposite systems can be used as light emitting structures with controllable electroluminescent properties.

It is shown that, in the ¹H NMR spectra of 5CB, the splitting of proton bands is the result of the dipole-dipole interaction. Using the value of the splitting of the ¹H bands, we determined the order parameters S for some fragments of 5CB molecules in the nematic phase. It is found that the values of S for the biphenyl core are twice greater than that for alkyl radical, which is the evidence for different dynamics of these structure fragments. From the analysis of the form of bands in the ¹H spectra in the hetereogeneous system 5CB-MCM, we showed that, in the temperature range of the existence of the nematic and crystal phases of bulk 5CB, there is no ordering of these molecules in the channels of MCM. This is caused by the appearance of defects in the liquid crystal ordering due to the interaction of some part of the LC molecules with the active centers of the surface of MCM channels.

Samples of disordered carbon obtained by different technologies (carbon plasma deposition, irradiation, anodic etching etc.) by Raman scattering (RS) and photoluminescence (PL) were studied. The common spectral features for these cardinally different technologies preparation samples are found. The following conclusion from the obtained data are made: • In some samples of disordered carbon there are carbon nanoparticles, which consist of a core containing sp² bonds and a shell containing sp³ bonds. Vibrations states of these bonds interact with each other. These nanoparticles have a strong photoluminescence in visible range of a spectrum; • On a surface of disordered carbon there can be metastable structural formations as the torn off chains. Lifetime of such structures is approximately half-year. Such structures most frequently arise on the irradiated surface.

Correlation between results of spectral investigation of structure of orientationally ordered wall adjacent layers (OOWL) of nonmesogenic liquids and theoretical simulation ofthese systems is analyzed. Theory was based on improved Mayer-Saupe microscopic model, which takes into account the interaction oftwo-component nematically ordered liquid (monomers and dimers) with the solid substrate surface. It was shown that theoretical results qualitatively coincide with experimental ones.

Spectroscopic characteristics of Davydov-split spectra of orientationally ordered adsorbate monolayer are considered. An appropriate generalizatibn and improvement of the existing theory are provided taking into account the electronic component of molecular polarizability. Formulae for integral intensities and frequencies of split spectral lines are presented as a result of the analytically solved equation for the polarizability tensor of the system. These formulae are exemplified by the adsorbed 2x 1 CO/NaC1 (100) monolayer. It is shown that consideration of the electronic component of polarizability reduces the discrepancy between the calculated and experimental Davydov splitting values from 25%to 5%.

Investigation of the properties of GWPs in a system of ZnO-6H-SiC type is an urgent and important problem of the modern-day physics. Here we studied the main properties of GWPs in the three-layer ZnO-6H-SiC system, namely, regions ofexistence, dispersion curves and energy characteristics (in particular, damping coefficients and spatial structure of the fields of phonon GWPs). Thus the results of our investigations indicate at some essential features of the regions of existence of GWPs in a system involving two semi-infinite layers separated by thin ZnO film. It is shown that the region of GWP existence in a three-layer system consists of two parts if unit cells of the film and substrate crystal lattices contain one oscillator. We studied dispersion curves for GWPs of E- and H-types (the optically active ZnO film being 0.5 and 1 μm thick). The frequency ranges were determined where the zeroth- and first-mode GWPs of both polarizations exist; these GWPs were excited in the above systems with different thicknesses ofthe optically active ZnO film.

Phenanthrene, a three ring aromatic hydrocarbon, is used as a model substance for study of intermolecular interactions in dilute solutions of organic solvents and water by spectroscopic method. Temperature dependencies of shift of the S₂ ←S_O spectrum of phenanthrene dissolved in apolar solvents and in liquid water are studied in this work. The spectroscopic data are used for analysis of the cavity radius R for phenanthrene molecule in solvents. It is shown that the value of R increases with temperature in organic solvents. In contrast, for water solution, the value ofR initially grows with temperature increase (in the interval of 273.3-296 K), but becomes constant at higher temperatures. The changes of water structure in the neighbourhood of a phenanthrene molecule and probable hypothesis about causes of R value constancy in high-temperature region are discussed. Conclusion about strengthening ofthe water structure in an aqueous cage with phenanthrene molecule inside is done.

Raman spectra of liquid methanol were registered in wide temperature range (150 - 340 K) at different rates of temperature changing for the frequency region 950 - 3700 cm^-1. Quantum chemical calculations of parameters of vibrational spectra of free molecule and of some associates were made. Comparison of these results and experimental data allows to insist that there are no monomers and dimers in liquid methanol. The only stable form is cyclic clusters. The widths ofthe bands do not depend on temperature and this fact indicates the stability of methanol structure in condensed state.

The kinetics of hydrogen exchange in molecular systems with H-bonds studied by kinetic IR spectroscopy and lowtemperature NMR spectroscopy methods is critically reviewed. The experimental rate constants and activation energies obtained so far for molecules capable of forming H-bonds as both proton donors and proton acceptor are collected and analyzed from the point of view of the influence of H-bond formation ability of the molecules-partners. The evidence available testifies to a molecular mechanism of the H-exchange reactions in inert solvents and in the gas phase via the formation of cyclic, mostly bimolecular, intermediates. The different mechanisms of the molecular H-exchange process in inert media are discussed and the possible paths ofexperimental elucidation ofreaction mechanism are offered.

Quantum chemical calculations of N,N'-diphenylguanidine (DPhG) molecule by the semiempirical MNDO-PM3 and AMI methods, ab initio HF/3-21G method and DFT B3LYP/6-3 1G(d,p) method give the arguments in favour of existence of this molecule as the asymmetric tautomer with the C=N- basic centre and the proton-donor NH₂ group. The results of JR and UV spectra, the dipole moments and the molecular weights determination of DPhG in low-polarity solvents support this conclusion and prove the formation of cyclic self-associates with two PhN-H...N(Ph)=C H-bonds in solutions. The predominant contribution of these dimers to self-association of DPhG in solution was supported also by the quantumchemical calculations.

The change in an external constant electric field of an electronic absorption coefficient of polymer films, doped by symmetric cationic polymethine dye is researched. This effect are characterised by an increase of intensity on shortwavelength edge of a band and its decrease on long-wavelength edge. The charge distribution in dye cation in model electric field 10⁷ - 10⁸ V/m of point charges and capacitor was calculated by method AMI. On the basis of the quantum chemical calculations the spectral regularities in electric field is interpreted by the change of electronic charge in the cation. The theoretical model based on change of value of eigen frequencies of charged anharmonic oscillators under operation field is offered for the description ofobserved effects. The experimental spectra well correlate with calculated theoretically.

1 D- and 2D ¹H NMR spectroscopy (500 MHz) has been used to study the self-association of a bifunctional intercalator, ethidium homodimer (EBH), in aqueous solution. A physical model describing the equilibrium ofdifferent associated forms of the homodimer in solution, including the most probable unfolded, folded conformations, dimer and trimer, has been developed. The magnitudes of equilibrium constants and thermodynamical characteristics of the complexation reactions have been obtained from analysis of the concentration and temperature dependences of proton chemical shifts of EBH molecules. Comparative analysis of the self-association parameters of ethidium homodimer and a monointercalator, ethidium bromide, enables to make some conclusions about structural features and energetic characteristics ofaggregates of aromatic molecules in solution.

NMR spectroscopy has been used to elucidate the molecular mechanism of solubilization action of hydrotropic agents nicotinamide (NA) and caffeine (CAF). Hetero-association of NA with riboflavine-mononucleotide (FMN) and CAF with low soluble in aqueous solution synthetic analogue of antibiotic actinomycin D, actinocyl-bis-(3-dimethylaminopropyl) amine (Actill), has been investigated by 500 MHz ¹H NMR spectroscopy. Concentration and temperature dependences of proton chemical shifts have been analysed in terms of a statistical-thermodynamic model of indefinite self- and heteroassociation of aromatic molecules. The obtained results enable to conclude that NA-FMN and CAF-Actill intermolecular complexes are mainly stabilized by the stacking interactions of the aromatic chromophores. Hetero-association of the investigated molecules plays an important role in solubilization of aromatic drugs by hydrotropic agents nicotinamide and caffeine.

Comparative study of the direction of OH-bond in H₂0 molecule in liquid and gas phases is carried out. The vibrational spectroscopy inverse spectral problem is solved with this purpose. The 3N-matrix method is used where the frequencies both eigen and non-eigen normal vibrations are included into evaluation procedure. It is found that the direction of chemical bond 0-H does not coincide with the direction of the straight line connecting the nuclei of the atoms 0 and H. Such deviation ofthe chemical bond is equal to 2° for a molecule H₂0 in gas phase and increases in liquid phase. The possibility of "mixing" forms of those normal vibrations which belong to the same irreducible representation of C₂ group is taken into account. "Mixing" forms of eigen and non-eigen normal vibrations of H₂0 molecule leads to further increasing of the deviation angle up to 7.5°. The existing ofthis effect may explain the well-known bending ofhydrogen bonds.

By ¹H NMR spectroscopy it was established that under increase ofcytosine concentration in anhydrous DMSO-d₆ from 5 up to 35 mM the doublet signal of its amino group becomes gradually transformed into singlet one. This observation is interpreted as a result of lowering of the barrier of amino group turn due to central symmetrical self-association of the base through two equivalent intermolecular H-bonds N1H...O=C2, which is likely to weaken pπ-conjugation of lone electron pair ofthe amino nitrogen atom with the ring π-electron system. The cytosine N1-methylsubstitution was shown to impact amino group in the similar way as self-association.

Within the frames of the factor analysis a new approach to extract spectra of components from spectra of solutions was developed. This allows one to determine concentrations of components without using a priori information. By this method, the JR spectra of tert-butyl hydroperoxide (TBH) in various solvents were investigated. In these solutions there are gauche and trans conformations ofmonomers ofTBH and self-associations ofTBH (dimers and trimers) are analyzed. The spectra of components and their concentrations are determined. Equilibrium constants of dimerization and trimerization and thermodynamic parameters of complexes are found. The factor analysis has been used in the spectroscopic study of trans and gauche conformations of 1,2-di-(p-nitrophenyl)ethane in acetone. The enthalpy and entropy differences of the trans and gauche conformations have been determined.

In this work we provided the investigations of electrooptical properties of liotropic ionic liquid crystals (LILC) doped with electrochromic admixture, namely with viologen. It was shown that under applying of electric field to LILC-viologen the electrochromic effect is observed. It manifests itself in colour change and in appearance of absorption bands on optical spectra. The action of the electric field also leads to the change of electric properties of the samples and to the change of parameters ofdouble electric layers existing near electrodes.

Using differential scanning calorimetry we study aging phenomenon, i.e. the out ofequilibrium evolution ofthe molecular compound 2-biphenylmethanol quenched into a glassy state, namely, the variations of the entropy at the glass transition on the waiting time after quench, and preparation (cooling rate) method was studied. It was found that variation of the entropy start being appreciable for the time spent in the glassy state more than 60 mm and is essentially constant for t <60 mm. It has also been studied kinetics of the glass transition at different cooling/heating rates, and has been found that there is a hysteresis effect in the temperature variation ofthe heat flow.

The dielectric constants ε′ and ε″ of a series of "liquid crystal (LC) - polymer" composites in the frequency region 10^-3-10⁵ Hz are measured. The composites are prepared by a photo-separation method with the variation of polymer content from 0 to 50 weight %. For all samples, a relaxation effect with a low relaxation frequency (10^-1-20 Hz) is observed. This effect is assigned to dielectric relaxation in the near-electrode layers. The experimentally observed increase of the relaxation frequency and the electric conductivity with polymer concentration is explained by incomplete phase separation occurred in "liquid crystal - pre-polymer" mixture under irradiation.

We present a microscopic analysis of origin of a helix in the nematic solvent with a dissolved chiral dopant. Obtained equations connect the helical pitch and helical twisting power of the chiral dopant with the twist angle of molecular long axes in the induced cholesteric liquid crystalline phase. Twist angle was obtained from results of computer modeling of intermolecular interactions in an ensemble of molecules of nematic solvent surrounding chiral dopant molecule. Results of calculations by the proposed method for the row of chiral dopants in two nematic solvents, N-(4-methoxybenzylidene)-4'- butylaniline (MBBA) and 4-pentyl-4'-cyanobiphenyle (5CB) are in good agreement with experimental data.

A new possible method of frequency tuning of the distributed feedback laser (DFB) based on cholesteric liquid crystals (CLC) is investigated. In this method the active media is irradiated with UV light to stimulate photo-transformation of the molecules of chiral dopant. This transformation changes twisting power of chiral dopant and, as results, the position of the reflection band of CLC. Based on this principle, fluent and reversable frequency tuning of the lasing irradiation of DFB-laser is realized.

Radiation-induced defects formed via electronic subsystem in solid Ne were studied combining thermally stimulated luminescence (TSL) and thermally stimulated exoelectron emission (TSEE) techniques. In the present paper the TSL and TSEE measurements of solid Ne were performed for the first time. The whole set of obtained experimental data suggests that in solid Ne at the temperature 10.5 K the annihilation of electronically induced defects occurs. Comparing experimental data with theoretical calculation the atomic configuration of radiation-induced defects was elucidated.

Metal alkanoates (systems based on lead decanoate with Co²⁺) under their melting were investigated. Electronic absorption spectra of Co²⁺ in the isotropic melt, ionic smectic mesophase and crystal phase were studied as a function of temperature. Dielectric properties and conductivity of ILC also were observed.

Helical twisting power and temperature dependence of the induced helical pitch have been determined for some representatives of mono- and bis-arylidene derivatives of 3R-methylcyclohexanone in nematic 4-pentyl-4'-cyanobiphenyl. Obtained data were analyzed in comparison with respective values for p-menthan-3-one derivatives studied earlier and also for some arylidene derivatives of various isomeric methylcyclohexanones. Regularities observed were shown to associate with peculiarities of spatial structures of the chiral compounds studied. A significance of hard connection of the central chirality and spiral chirality of the stereospecific twisted arylidene grouping is proved.

Two compounds from alkylcyanobiphenyl series, 4-n-pentyl-4'-cyanobiphenyl (5CB) and 4-n-hexyl-4'-cyanobiphenyl (6CB) were investigated by FTIR spectroscopy in the two phase states, namely crystalline and liquid crystal ones. The differences in the band shapes in the FTIR spectra of the two phases have been observed and analyzed in order to verify theoretical results regarding orientational order in the two phases of LC compounds. The spectral -structural correlations, which reflect the development of spatial geometry of the LC molecules, has been found.

For the first time, electronic spectra of 2-biphenylmethanol (2BpM) in crystalline state and in solution with different polarity were investigated. UV absorption and emission spectra of 2-biphenylmethanol (2BpM) was investigated in different conditions The spectra of 2BpM were measured in crystalline state and those dissolved in non-polar and polar solvents. Different number of bands in the emission spectra in crystalline and in solution has been observed.

Temperature measurements of ¹H NMR spectra in (CD₃)₂S0 solutions have been carried out for 2,6-bis-[4-(4-methoxybenzoyloxy)-benzylidene]-3(R)-methylcyclohexanone as a model compound for smectogenic C* homologues demonstrating an inversion of the spontaneous polarization sign to clarify an opportunity of configurational and conformational changes with the temperature rise as origins of this effect. In the temperature ranges 30 - 110°C, spectral evidences in favor of the possible temperature-induced E→Z isomerization were not revealed. At the same time, changes found in vicinal spin-spin couplings in combination with data of molecular simulation by the semi-empirical PM3 method allowed to determine an appreciable displacement of the chair ↔ twist-boat conformational equilibrium for the cyclohexanone ring with temperature in direction of the increase by 15 % of the fraction of twist-forms. However, it was demonstrated with molecular simulation this process cannot result in a substantial alteration in the value and direction of the dipole moment. This concerns also intra-molecular rotation in the exocyclic fragments of isolated molecules resulting in conformers with quite different dipole moments, but with the very close energies and populations in the whole temperature interval studied. The single factor responsible for the inversion of the spontaneous polarization sign can be surmised to be changes in conformational energetics.

In JR spectra for region of phase transition "order-orientation disorder" is observed the temperature dependence of the Davydov splitting value for in-phase CH₂ rocking vibrations of pure crystalline n-paraffins C_nH_2n+2(n=19, 21, 23, 30, 32). Within the frameworks of crystal thermal expansion model the Davydov splitting value of vibration frequencies for pure n-paraffins weakly depends on temperature in all temperature range of crystalline phase existence. A statistic and dynamic model is proposed, which provides adequate description of the observed effect. Jn the framework of this model, the damping of vibrational excitons on orientational defects of different nature takes place. Genesis of such defects is connected with excitation of librational and rotational molecular degrees of freedom at the crystal transitions into high-temperature orthorhombic and hexagonal crystalline states. Theoretical analysis of the effect of resonance dynamical intermolecular interaction on the spectra of intramolecular vibrations of the crystals was performed in terms of stochastic equations with account of phase transitions. Computer simulation of such dependence was performed for pure n-paraffin compounds. Good agreement between the experimental and computer simulation results was obtained.

In this paper we calculated an electric field produced by interdigital electrodes in IPS-mode analytically and compare them with our numerical calculations. The results for the threshold voltage in our model and it dependence on the cell sickness and electrode gap are in the good agreement with the experimental data of Matsumoto (et. al). Also we proposed optimized cell geometry for the IPS mode that corresponds to the smallest threshold voltage. Using the results for the electric field we found the director profile in our model for the nematic cell with the strong director anchoring.

We present theoretical study of optical singularity birth in a wave front of Gaussian light beam with initially smooth wave front. A linearly polarised Gaussian beam illuminates the homeotropically aligned nematic liquid crystal (NLC) cell. Strong director anchoring at the cell walls is assumed. Equilibrium director profile is determined by the minimum of the total free energy. Functional minimum is found numerically solving Euler-Lagrange equations. We find the threshold intensity for light induced Frederiks-type transition. Utilizing the Huygens-Fresnel principle, quasi-isotropic and geometrical optics approximations we calculate the amplitude distribution in space for different distances from the cell. In the case of stigmatic Gaussian beam we have a ring of zero amplitude of the beam. Thus the edge dislocation of a wave front is born.

This paper concerns with our measurements of reaction center (RC) volume changes in the course of photoactivation using method of holographic interferometry. As a principal value, we studed change of a solution refraction index (▵n) influenced by the sample volume expansion due to temperature changes (▵n_T), light absorption (▵n_abs) and changes in the volume of photoactive molecules (▵n_V). Using the scheme of temperature compensation we could reduce the task of the case ▵n_T<<▵n_abs, ▵n_V Our estimation for the case of a protein solution yields in relative changes in the molecular volume within 10^-3 ÷ 10^-2.

Conformation analysis of mutated DNA-bacteriophages (PLys-23, P23-2, P47- the numbers have been assigned by T. Pererva) induced by MS2 virus incorporated in Ecoli AB 259 Hfr 3000 has been done. Surface enhanced infrared absorption (SEIRA) spectroscopy and principal component analysis has been applied for solving this problem. The nucleic acids isolated from the mutated phages had a form of double stranded DNA with different modifications. The nucleic acid from phage P47 was undergone the structural rearrangement in the most degree. The shape and position ofthe fine structure of the Phosphate asymmetrical band at 1071cm^-1 as well as the stretching OH vibration at 3370-3390 cm^-1 has indicated to the appearance ofadditional OH-groups. The Z-form feature has been found in the base vibration region (1694 cm^-1) and the sugar region (932 cm^-1). A supposition about modification of structure of DNA by Z-fragments for P47 phage has been proposed. The P23-2 and PLys-23 phages have showed the numerous minor structural changes also. On the basis of SEIRA spectra we have determined the characteristic parameters of the marker bands of nucleic acid used for construction of principal components. Contribution of different spectral parameters of nucleic acids to principal components has been estimated.

A stepwise hydration of bovine serum albumin is studied using infrared spectroscopy. For determination of the configuration interactions of hydrating H₂0 molecules to specific protein parts evaporation spectra were used. Evaporation spectra were calculated by subtraction of the spectra of hydrated protein from the spectrum of the dry protein. Evaporation spectra are further processed with a novel method, which is based on the decomposition of the original spectra into basic vectors (spectra). For detailed assignment of the basic spectra the temperature measurements and H/D exchanged were used. Upon the assignment of the basic vectors several interaction configurations of H₂0 molecules attached to specific protein sites as a function of the hydration level were proposed.

The method of conformational probes has been developed. The conformational mobility of probes introduced into poly(methyl methacrylate) (PMMA) and having different sizes of rotational fragments (V_p^≠) has been investigated. There is a correlation between the freezing temperature of probe conformational transitions (T_f) and V_p^≠. These data have been considered within the frameworks of the free volume theory and the relaxational transitions. Conformational mobility of probes in poly(vinyl trimethylsilane) (PVTMS) and poly(trimethylsilyl propyne) (PTMSP) with a large free volume fraction has been studied.

Complexation of anthracycline antibiotic daunomycin (DAU) with self-complementary deoxyhexanucleotide d(GCATGC) in aqueous solution has been investigated by one-dimensional and two-dimensional homonuclear 'H NMR spectroscopy (TOCSY and NOESY) and heteronuclear 'H-31P NMR spectroscopy (HMBC). Quantitative determination of parameters of oligonucleotide self-association and its complexation with DAU was based on the analysis of the dependences of proton chemical shifts on concentration and temperature. Experimental results were analysed in terms of the equilibrium reaction constants, limiting proton chemical shifts and thermodynamical parameters (enthalpies AN, entropies AS) of the formation of hexamer duplex and different drug-DNA complexes. The most favourable structures of the single-stranded form of d(GCATGC) and the intercalated DAU-hexamer complex have been determined using X-PLOR software taking into consideration both intra- and intermolecular NOE contacts.

Concepts of negative (reverse) emission fluxes studied theoretically and experimentally by B.I. Stepanov in optics are represented. The results of observations and medical applications of negative fluxes of millimeter emission showing its high therapeutic efficiency are given.

6-thioguanine has long been in use as an anticancer drug. In the recent years 6-thioguanine and its derivatives are coming into application as photosensibilizers, luminescence probes, targets for forming photo-crosslinks. To ascertain spectroscopic properties of 6-thioguanine, its UV absorption, low temperature (4.2K) luminescence and circular dichroism spectra were studied in solutions of different polarities. Spectrophotometric titration of 6-thioguanine was carried out in the pH 1-13 interval. The MP2 ab initio method was used to calculate the molecular structure, dipole moments, electronic density distribution, thermodynamic characteristics, UV and JR spectra of some 6-thioguanine tautomers. Based on theoretical calculations and experimental results, a diagram of electronic excited states of 6-thioguanine and a scheme of acid-base and tautomeric equilibrium of 6-thioguanine in the polar solvent were built. Migration of excitation in DNA with incorporated 6-thioguanine was investigated. As well, we used 6-thioguanine as a luminescent probe to study structural changes in cryoprotector and DNA solutions in the temperature range from 4.2 to 273K. In particular, glassification of the DNA hydrate shell in the range of 200K was revealed.

In ¹H NMR spectra of four nucleosides of uracil and thymine - U, dU, T and rT - in anhydrous DMSO in the presence of carboxylate-ion there was observed disappearance of signals of the N3H aglycon protons and all the hydroxyl protons of glycosylic fragments. This changes were interpreted as a result of the N3H - 02H proton transfer in the base residues under the complex formation between nucleosides and ligand molecules: one carboxylate-ion forms two H-bonds with groups 02H and 05'H, another - two H-bonds with hydroxyl groups 02'H and 03'H in the case of a riboside or one Hbond with group 03'H of a deoxyriboside. Orders ofthe complexes' stability were established, which from, particularly, the conclusion was drawn that the canonical nucleosides U and T form more stable complexes with carboxylate-ion, than metabolites dU and rT. Biological significance ofthe results obtained is pointed out.

Solid phase luminescence determination of aluminum using UV laser and optical multichannel spectra analyser (OMA) was descnbed Silica (SG) modified sith ion associate high molecular eiglu quatemar ammornurn salt (QAS) lumogallion (LG) was used as active sensor element Photoluimnescence (PL) of the modified sorbent as excited b) pulse N2 laser and then studied by OMA using CCD camera for detection of the pulse PL spectra and IBM PC for analyses It was shown that the intensity of PL pulse peaks of the modified SG noticeabl increased ith the nsing of Al (III) concentration in the range of 1 10^-6 ÷ 1 10^-4M. The detection limit of Al as 1 10^-7 mole/1 at sample volume 50 ml and mass of the sorbent 0.05 g. PL spectra of Al-LG complex formed on the surface is consisted of two bonds Their possible reasons are discussed The developed method can be successfully used for working out optical sensor for aluminum determination in the environment.

Absorbtion spectra, fluorescence spectra and quantum yields of dyes of various classes in cholesteric liquid crystals (CLC) and in isotropic solutions as well as the thresholds oftheir lasing in CLC were investigated. The increase ofquantum yields of dyes in concentrated CLC-solution in comparison with diluted isotropic ones are established for the first time. It has been shown that neutral phenolenone dyes with voluminose terminal groups which hinder aggregation of their molecules in concentrated solutions. The experimental investigations of the lasing efficiency of a distributed feedback laser (DFB) based on CLC from excitation intensity and optical density of dye in the active layer are presented. The thermal phase grating induced by laser radiation in doped CLC, as it is shown, the high << effective Q>> of the CLC layers are compensated and the lasing efficiency of this lasers are improved.

The interaction of circularly polarized weak probe wave with the molecular iodine driven by the strong pump wave with the opposite polarization has been theoretically studied. It is shown that the phenomenon of electromagnetically induced transparency in the iodine vapour can be observed for moderate intensity (~10-100 W/cm²) of the pump wave. The group velocity of the probe wave can decrease to 0.1c.

The use of the method of enhancement of infrared absorption by rough metallic surface (SEIRA) allows one to increase the probability of infrared transitions and to reveal a series of spectral manifestations of structural features of biological molecules. We analyzed various experimental techniques which gives a possibility to achieve enhancement in the infrared (IR) spectra. We studied the applicability of the SEIRA techniques for analysis of nucleic acids, lipids, and membranes. Under the conditions of our experiment and according to literature data, there was observed enhancement factor equal to 3-20 for vibrations of various molecular groups. Peculiarity of another optical amplifier, namely, colloidal gold that effectively used for enhancement of signal in JR absorption and Raman scattering, have been studied. We made an attempt to model the effect of enhancement of electrical field and their frequency dependence for different metal surfaces and obtained that silver, gold and copper are the best.

Step Scan creates an identical JR modulation frequency over the entire JR spectrum. This is a prerequisite for quantitative photoacoustic spectroscopy and depth profiling. 2D conelation maps have been created for photoacoustic spectra as well as for dynamic difference spectra of polymers under periodic external mechanical perturbation. From the positions and signs of cross peaks in the 2D-maps the relative direction and timing of reorientational motions can be determined Depth profiling has been demonstrated on ethylene-vinyl acetate copolymer on polypropylene. The effects of mechanical stress on polymers using 2D-FT-IR ofhave been shown for isotactic polypropylene and a polyesther/polyurethane block copolymer.

The electron energy distribution function (EEDF) in a hollow-cathode glow discharge in mixtures of nitrogen with electronegative gases is investigated. It is shown that small admixtures of SF₆ or CCI₄ to nitrogen significantly increase the number of electrons in the energy range 2-6 eV which corresponds to the inverse part of the EEDF .In nitrogen with small admixtures of F₂ or NF₃, the EEDF differs slightly from that calculated for pure nitrogen. The EEDF in these mixtures substantially depends on electron attachment to electronegative gas molecules.

Excitonic absorption, reflection and photoluminescence spectra of mixed Zn(P_1-χAs_χ)₂ crystals over the full range of χ (0 ≤ χ 1) and Zn_1-χ Cd_χP₂ crystals at 0 ≤ χ ≤ 0.05 have been studied at low temperatures (1.8 K). The decrease of the energy gap in Zn(P_1-χAs_χ)₂ at the increase of χ occurs slightly sublinearly. The rydbergs of excitonic series in this crystals decrease as well, and the dependences Ry(χ) for all series are strongly superlinear at small χ. In Zn(P_1-χAs_χ)₂ crystals the energy gap and rydbergs decrease at the increase of χ (at 0 ≤ χ ≤ 0.05) as well. The dependences of Eg and Ry on χ are considerably stronger in Zn(P_1-χAs_χ)₂ than in Zn_1-χCd_χP₂. At the increase of χ the half-width of excitonic absorption lines increases monotonically in both type crystals that is evidence of the increasing role of fluctuations of crystal potential.