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1
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Vibrational Corrections to Transition Properties

100%
Pluta T., Sadlej A. J.
Acta Physica Polonica A
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2000
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vol. 98
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issue 4
363-371
EN
The vibrational contributions to second-order transition properties are considered in the framework of the Born-Oppenheimer approximation. It is shown that the usual formula for vibrational second-order transition matrix elements is incomplete and needs to be supplemented by a term of purely vibrational origin. This pure vibrational contribution is calculated for vibrational transition polarizabilities in LiH and BeF and found to be quite significant. Its inclusion in theoretically calculated data for the Raman intensities appears to be necessary.
2
Content available remote

On the Franck-Condon Effects in the Absorption Spectrum of C_{10}H_{8} Anion. the Analysis Based on the AB Initio MCSCF Method

100%
Andruniow T., Pawlikowski M.
Acta Physica Polonica A
|
1998
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vol. 93
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issue 5-6
707-715
EN
The near-IR, visible and UV regions of the absorption spectrum of naphthalene anion (C_{10}H_{8}^{–}) are studied in terms of full optimized reaction space multiconfiguration self-consistent field method applied with Dunning's double-zeta basis set including polarization and diffuse functions on the all hydrogen atoms. Computed Franck-Condon activity of the all (nine) totally symmetric vibrations in the seven low-energy transitions is discussed and compared to the available experimental data. The assignment for some electronic transitions in the visible part of the naphthalene anion absorption spectrum is corrected on the base of full optimized reaction space multiconfiguration self-consistent field computations. We have argued that two (overlapping) bands at 21700 cm^{-1} and 26800 cm^{-1} are due to 1^{2}B_{1g} → 1^{2}A_{u} and 1^{2}B_{1g} → 2^{2}A_{u} transitions rather than to the short-axis and long-axis polarized ones as was suggested in an earlier semiempirical treatment. An experimental method appropriate to verify this result is proposed.
3
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Franck-Condon Effects in Resonance Raman Spectra of TCNQ^{-} and C_{10}H^{+8} Radicals. A Search for Dushinsky Rotation of Totally Symmetric Modes

100%
Zborowski K., Pawlikowski M.
Acta Physica Polonica A
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1995
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vol. 88
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issue 3
435-444
EN
The resonance Raman spectra of tetracyanoquinodimethane anion (TCNQ^{-}) and naphthalene cation (C_{10}H^{+8}) are analyzed in terms of theoretical model based on the Franck-Condon effects. The model includes also the effect of rotation of totally symmetric normal coordinates upon electronic excitation to the resonant state (Dushinsky effects). It is shown that such a simple model accounts correctly for the available resonance Raman spectra for TCNQ^{-} and C_{10}H^{+8} radicals. The possible model refinements such as vibronic coupling effects are also briefly discussed.
4
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Depolarization Dispersion of Totally Symmetric Fundamentals in Resonance Raman Spectra. Analysis for Azobenzene Dyes

100%
Sassi P., Pawlikowski M.
Acta Physica Polonica A
|
1996
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vol. 90
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issue 3
509-518
EN
The resonance Raman excitation profiles and depolarization dispersions for totally symmetric vibrations are studied under the energy region corresponding to an excitation of two low-energy states of 4-nitro-4'-diethylaminoazobenzene dye. In a contrast to the earlier analysis of this dye we assume that the low-energy states of the molecule studied have different polarizations. It results in the depolarization dispersions of the Raman lines of totally symmetric vibrations. The effect is illustrated for two vibrations: ν_{4}=1342 cm^{-1} and ν_{7}=1448 cm^{-1} for which excitation profiles show distinctive intensity distribution patterns due to interferences between the vibrational manifolds of the overlapping states. The nature of the electronic (resonant) states and the magnitudes of Franck-Condon parameters determined from the experiment are also briefly discussed.
5
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Evaluation of Tomato Juice Quality Using Surface Enhanced Raman Spectroscopy

63%
Malekfar R., Nikbakht A., Abbasian S., Sadeghi F., Mozaffari M.
|
|
issue 6
971-973
EN
Tomato (Lycopersicon esculentum L.) is a valuable fruit cultivated in the world as an important plant. There are a lot of industries engaged with the drying, processing, quality control and sorting of tomato. A rapid and reliable measurement of qualitative factors of tomato and its products can be a serious necessity for the producers and industrialists. The objective of this research was to implement SERS as a modern technique to evaluate some qualitative parameters of tomato juice. To prevent the effect of cartenoids and florescence background, the juices were centrifuged. Silver colloid was prepared according to Lee and Meisel method for SERS experiments. The results were compared with the spectra obtained from ordinary spontaneous Raman spectroscopy technique data. Three major bands assigned to carbohydrates in tomato were detected and analyzed. Moreover, a medium band related to proteins could be identified. Comparison of SERS spectra with the normal spontaneous Raman spectra proved that SERS has a privilege in the measurement of carbohydrates and proteins as an effective, rapid and precise technique.
6
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Laser Raman and Infrared Absorption Spectra of 2,4-dichloronitrobenzene

51%
Rastogi V., Jain D., Mital H., Sharma S.
Acta Physica Polonica A
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1991
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vol. 79
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issue 6
765-774
EN
The laser Raman and infrared absorption spectra of 2,4-dichloronitrobenzene have been recorded in pure liquid state. The vibrational spectra have been analysed assuming C_{s}, point group for the molecule. The assignments for fundamental vibrations, combination and overtone frequencies and internal modes of vibrations of NO_{2} group have been proposed.
7
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Activation of Silver Colloids for Enhancement of Raman Scattering

51%
Kruszewski S., Cyrankiewicz M.
Acta Physica Polonica A
|
2011
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vol. 119
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issue 6A
1018-1022
EN
Obtaining of systems that provide ever-increasing enhancement of the Raman scattered light is a big challenge. The silver colloids obtained by reduction of silver nitrate by trisodium citrate are the most promising enhancement systems. Nanoparticles of silver forming fresh colloid obtained by this way exhibit in extinction spectrum the absorption band proving of the surface plasmons excitation, but do not enhance the Raman scattered light, are not surface enhanced Raman scattering active. Adding of KCl or HNO_3 causes the surface enhanced Raman scattering activation, i.e. causes that the conditions for aggregation of nanoparticles and for adsorption on their surface of molecules providing Raman scattering are created. Increasing amount of added KCl or HNO_3 leads to significant changes in the extinction spectrum and to significant increase in intensity of surface enhanced Raman scattering. The observed changes in extinction spectrum are mainly due to progressive aggregations of nanoparticles. In junctions between nanoparticles existing inside aggregates the condition for single molecule surface enhanced Raman scattering are fulfilled and therefore aggregation leads to increase in average surface enhanced Raman scattering intensity. Silver colloid activated by using KCl provides about 10-fold higher surface enhanced Raman scattering than that treated with HNO_3.
8
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Characterisation of Porphyrin-TiO_2 Complex Using Raman Spectroscopy and Electron Paramagnetic Resonance

51%
Kotkowiak M., Manikowski H., Wieczorowski M., Dudkowiak A.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
353-356
EN
A complex of meso-tetrakis (4-sulphonatophenyl) porphyrin covalently linked to titanium dioxide has been studied. Illumination of the complex with visible light was shown to result in formation of cationic radicals of the porphyrin. Shape and kinetics of the electron spin resonance signals were analysed which permitted calculation of spectroscopic parameters characterising the photoinduced process of the radicals formation. The dye-semiconductor complex was thoroughly characterised to indicate its possible applications.
9
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Content available

Magnetochiral Effect in H_h and V_h Components of Rayleigh Light Scattering by Diamagnetic Molecular Systems

51%
Woźniak S.
Acta Physica Polonica A
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2001
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vol. 100
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issue 4
517-528
EN
A static magnetic field B^0, acting on a chiral liquid perpendicular to the propagation direction of an optical beam, is shown to induce a magnetochiral change of Rayleigh light scattering which is different in sign for the light scattered parallel and antiparallel to B^0. It is related to the electric dipole and magnetic dipole or/and electric quadrupole moments induced simultaneously in a chiral molecule by electric dipole interaction with electromagnetic radiation. For diamagnetic molecules the effect is described by linear and nonlinear polarizabilities, responsible also for circular birefringence (natural optical activity and the Faraday effect) as well as axial (magnetochiral) birefringence.
10
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The Dynamics of Benzene Molecules in Liquid Carbon Tetrachloride Solution

51%
Lewandowska D., Trumpakaj Z., Śliwiński A., Grzywacz J.
Acta Physica Polonica A
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1991
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vol. 80
|
issue 1
15-21
EN
Results of the investigations of C_{6}H_{6} and CCl_{4} binary solutions by two methods: dispersion of light and viscometry, as functions of the concentration and temperature are reported.
11
Publication available in full text mode
Content available

Comparative Study of Orientational Order of Some Liquid Crystals from Various Homologous Series

51%
Bielejewska N., Chrzumnicka E., Mykowska E., Przybylski R., Szybowicz M., Władysiak K., Bauman D.
Acta Physica Polonica A
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2006
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vol. 110
|
issue 6
777-793
EN
The long-range orientational order of liquid crystals from homologous series of 4-n-alkyl-4'-cyanobiphenyl, 4-n-alkoxy-4'-cyanobiphenyl, trans-4-n-alkyl(4'-cyano-phenyl)-hexane, and 4-(trans-4'-n -alkylcyclohexyl)-isothiocyanato-benzene was studied by means of classical methods of optical spectroscopy: absorption of the polarized light, fluorescence depolarization, and Raman scattering depolarization. The absorption, emission, and Raman scattering spectra of linearly polarized light were recorded as a function of temperature in the whole range of the mesophase. On the basis of these spectra the order parameters ⟨P_2⟩ and ⟨P_4⟩ as well as the orientational distribution function were determined. The results obtained for members of various series with the same number of carbon atom in the alkyl chain were compared. It was found that the orientational order of liquid crystal molecules depends on the structure of the rigid core, on the kind of the terminal group as well as on the alkyl chain length. The odd-even effect for the order parameters, explained as the alteration of interaction between alkyl chains, was observed.
12
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Study of SrLaAlO_{4} and SrLaGaO_{4} Substrate Crystals by Raman Spectroscopy

51%
Drozdowski M., Kozielski M., Pajączkowska A.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 1
139-142
EN
In this paper the study of SrLaAlO_{4} and SrLaGaO_{4} single crystals using the Raman scattering method is presented. The obtained results are discussed in terms of nature of the crystallografic imperfections and point defects which might arise during the crystal growth process.
13
Content available remote

Enhancement of FITC Fluorescence by Silver Colloids and Silver Island Films

51%
Kruszewski S., Wybranowski T., Cyrankiewicz M., Ziomkowska B., Pawlaczyk A.
Acta Physica Polonica A
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2008
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vol. 113
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issue 6
1599-1608
EN
Silver colloids and silver island films as fluorescence enhancement systems are the subject of this paper. Enhancement of fluorescence of molecules placed near metallic nanoparticles is a result of resonance interaction of exciting and emitted lights with surface plasmons. Two models explaining this phenomenon are presented. Processes of silver colloids and silver island films forming are described. Results of extinction, absorption and scattering studies of fluorescence enhancement systems are presented. The influence of these systems, i.e. silver colloids and silver island films on the fluorescence of fluorescein-5-isothiocyanate was studied. 7-fold increase in fluorescence intensity of fluorescein-5-isothiocyanate molecules placed near silver nanoparticles was observed.
14
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Elastooptic Constants of SrLaAlO_{4} and SrLaGaO_{4} Single Crystals Determined by Brillouin Scattering

51%
Drozdowski M., Pajączkowska A., Kasprowicz D., Ziobrowski P., Gloubokov A.
Acta Physica Polonica A
|
1997
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vol. 92
|
issue 1
177-181
EN
In this paper we report the elastooptic constants p_{ij} of strontium lanthanum aluminate, SrLaAlO_{4} and strontium lanthanum gallate SrLaGaO_{4} single crystals, which were determined at room temperature using Brillouin scattering method. In order to investigate the elastooptic constants of SrLaAlO_{4} and SrLaGaO_{4} single crystals, a substitution method proposed by Cummins and Schoen, and developed by Nelson and Lax was used. The obtained results are also discussed in terms of the nature defects which might arise in these crystals during growth process.
15
Content available remote

Aggregated Silver Sols as SERS Substrates

51%
Kruszewski S., Cyrankiewicz M.
|
EN
The unique plasmonic properties of the noble metal colloidal nanoparticles make them promising enhancement substrates for surface-enhanced Raman scattering. Obtaining of systems that provide ever-increasing enhancement of the Raman scattered light is a big challenge. Silver colloids studied here are prepared by Lee-Meisel's method. Rhodamine 6G and rhodamine B are used as probe adsorbates. The "raw" colloids obtained in this way exhibit a characteristic extinction band proving surface plasmons excitation, but do not enhance the Raman signal. Theoretical calculations indicate that the extremely large electromagnetic field is induced in the junctions between metallic nanostructures so some degree of their aggregation is necessary to achieve a sufficient gain value. The addition of aggregating agents (KCl or HCl) leads to significant changes in the extinction spectrum and to significant increase in the intensity of surface-enhanced Raman scattering. The experiments show that chloride can not only promote the aggregation process but also effectively affect chemical mechanisms contributing to surface-enhanced Raman scattering.
16
Content available remote

Rhodamine 6G as a Mediator of Silver Nanoparticles Aggregation

45%
Kruszewski S., Cyrankiewicz M.
Acta Physica Polonica A
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2013
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vol. 123
|
issue 6
965-969
EN
Surface-enhanced Raman scattering is the phenomenon where a huge increase of Raman scattering intensity from molecules situated close to the metal nanoobjects is observed. Our study is focused on the method of SERS-activation of silver nanoparticles and, in the future, the application of thus obtained SERS substrates for biomedical purposes. As expected, the intensity of Raman scattering from rhodamine 6G used here as a SERS probe strongly increase during the early stages of aggregation of silver sol. Moreover, the evolution of extinction spectra and changes in the degree of the colloid aggregation observed in DLS measurements point out that molecules of the dye do not participate passively in the aggregation process but greatly affect its course.
17
Content available remote

Experimental and Quantum Chemical Calculations of 2-Amino-4,5,6,7-Tetrahydrobenzo[b]Thiophene-3-Carbonitrile

38%
Oturak H., Kaya Kinaytürk N., Topuz M., Kutlu N., Kaynaker E., Talıp P., Sert Y.
Acta Physica Polonica A
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2017
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vol. 132
|
issue 3
1192-1199
EN
Vibrational frequencies of 2-Amino-4,5,6,7-Tetrahydrobenzo[b]Thiophene-3-Carbonitrile were calculated using density functional (DFT/B3YLP) method with 6-311++G(d,p) basis set by Gaussian 09. The assignments of the vibrational frequencies have been done by potential energy distribution analysis, using VEDA 4 software. The density functional theory and time dependent density functional theory methods have been used to study the electronic properties of 2-Amino-4,5,6,7-Tetrahydrobenzo[b]Thiophene-3-Carbonitrile. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital method. All computed spectroscopic properties were compared with experimental ones. The simulated spectra of the molecule show excellent agreement with the experimental spectra.
18
Content available remote

Silver Nanoparticles as Enhancing Substrates for Raman and Fluorescence Spectroscopy

38%
Cyrankiewicz M., Wybranowski T., Kruszewski S.
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|
vol. 125
|
issue 4A
A-11-A-15
EN
The enhancing properties of silver nanoparticles in surface-enhanced Raman scattering (SERS) and metal-enhanced fluorescence (MEF) are studied in this work. The obtained results confirm that the partial aggregation of nanoparticles leads to a great increase of Raman scattering cross-section but there are significant differences in SERS-activity of colloidal silver treated with various aggregating compounds. The differences are interpreted through the analysis of both experimental and computational results. The same silver colloid covered with silica shell preventing the fluorescence quenching makes possible a several-fold increase in fluorescence emission. The effect strongly depends on thickness of the outer layer of nanoparticles. Geometrical parameters of nanoparticles (radius or radius and thickness of the adsorption layer in core-shell systems) are determined on the basis of the dynamic light scattering (DLS) data and extinction spectra analysis.
19
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Spectral Investigations of Fullerene-Porphyrin Complexes

32%
Barszcz B., Bogucki A., Laskowska B., Ion R., Graja A.
Acta Physica Polonica A
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2007
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vol. 112
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issue S
S-143-S-152
EN
Spectral investigations of someμ-oxo-dimer complexes of trivalent metals (Mn, Fe) with two different ligands: tetraphenylporphyrin and tetranaphthylporphyrin (TNP), and fullerene (C_{60} and C_{70}) complexes withμ-oxobis[5,10,15,20-tetraarylporphyrinatometal (III)] (TXP-M)_2O dimer, where M = Fe, Mn and X = phenyl or naphthyl, are presented. Discussion of the main electronic and vibrational bands observed in the UV-Vis-IR and Raman spectra of both classes of fullerene-porphyrin systems is given. Experimental data are completed with the quantum chemical calculations of MnTNP^+ component.
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