bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman spectra of bismuth trihalides in the solid and liquid states
Authors: Ichikawa Kazuhiko , Fukushi Kohji 
Published: May 2005

AbstractRaman spectra were measured for BiBr3 and BiCl3 in the polycrystalline and liquid phases. A new assignment for BiBr3 is proposed on the basis of the temperature dependence of the Raman spectra. An abrupt spectral change originating from an order‐disorder phase transition was observed in BiBr3. In the liquid phase, both compounds showed a very broad composite spectra in the Bi–X stretching vibration region, which can be understood as originating from a mixture of multiply charged bismuth halide complexes in addition to the monatomic halide anions.
Raman spectroscopy of submicron surface layers of crystals and films
Authors: Sushchinsky M. M. , Gorelik V. S. 
Published: May 2005

AbstractEvidence for surface phonon modes has been found in the Raman spectra of bulk single crystals and in crystalline powders. The Raman spectra of distorted submicron layers and films have been studied as functions of the character of ion implantation and the type of subsequent annealing. The phenomenon of inelastic light hyperreflection from a crystal surface has also been observed.
Raman spectra of agyrodites, M6PS5X (M = Cu and Ag; X = Cl, Br and I), and some related thiophosphates
Authors: Shamir Jacob , Fiechter Sebastian , Wetzel Herbert 
Published: May 2005

AbstractRaman spectra of copper and silver agyrodites containing different halides were studied. The observed spectra are very similar to those of copper and silver thiophosphates. The spectra were interpreted as resulting from internal modes of the tetrahedral thiophosphate anion, PS43−, indicating that these agyrodites can possibly be formulated as triple salts, M3PS4 · M2S · MX (M = Cu and Ag; X = Cl, Br and I), being basically ionic compounds consisting of monoatomic ions with only polyatomic one covalently bonded PS43− anion.
Trace analysis of tetrasulphonated copper phthalocyanine by surface enhanced Raman spectroscopy
Authors: Aroca Ricardo , Martin Fernando 
Published: May 2005

AbstractSilver island films are shown to be stable under normal laboratory conditions, and easy to use as optical sensors for the detection of traces of tetrasulphonated copper phthalocyanine. The surface‐enhanced Raman (SER) effect is used in conjunction with a resonance Raman (RR) increase in the analytical signal to levels that allow the detection of nanogram amounts. The relative intensities of characteristic group frequencies do not seem to be altered by the SER enhancement mechanism.
Assignment of iodine BX lines by resonant coherent anti‐stokes Raman spectroscopy
Authors: Dimov S. S. , Pavlov L. I. , Stamenov K. V. , Khadzhiisky N. G. 
Published: May 2005

AbstractA resonant CARS scheme is described, which allows the examination of the I2 spectrum for discrete and continuum resonances simultaneously. This is the first time such a method of excitation for molecular species has been demonstrated. The absence of P and R branches determined by double resonances with the signal and the pump frequencies makes the assignment easier. It is possible to record all the Raman lines of O, Q and S types, whereas for continuum CARS mainly S lines are detected. The proposed technique makes the spectral structure clearer and the identification simpler. When the temperature of I2 vapour is increased to 330 K, some new Raman lines, the sixth and seventh overtones, are obtained, because of population of higher excited vibrational states. The variation of the anti‐Stokes signal Ia with iodine vapour pressure has also been investigated.
Single‐crystal micro‐Raman studies of ZrS3, TiS3 and several Zr1–xTixS3 compounds (0<x⩽0.33)
Authors: Gard P. , Cruege F. , Sourisseau C. , Gorochov O. 
Published: May 2005

AbstractRaman and resonance Raman spectra (100–1000 cm−1) of ZrS3, several Zr1–xTixS3 ternary compounds (0<x⩽0.33) and TiS3 single crystals have been obtained using a micro‐Mole Raman instrument. For ZrS3, when using the 514.5 nm exciting line, the αyy and αxx polarizability components give rise to different resonance Raman spectra, demonstrating definitely that two distinct allowed excitonic transitions are contained in the lowest energy absorption band at ca 500.0 nm. In the ternary phase Zr1–xTixS3, the mode behaviour of long‐wavelength optical phonons were investigated through the composition range 0<x⩽0.33: a mixed one‐, two‐ and three‐mode behaviour was observed, depending on the nature of the vibrations; in particular, the three‐mode behaviour of the diatomic v(SS)2− mode can be well accounted for in terms of S22− pairs surrounded by either Zr4+, Ti4+ or Zr4+ and Ti4+ ions and the relative intensities of the three components are in agreement with a statistical distribution of titanium within the ZrS3 type structure. Finally, new polarized Raman spectra of TiS3 have been obtained and band wavenumbers of the Raman active phonons in these compounds compared.
Surface‐enhanced Raman spectroscopy of DNA bases
Authors: Otto C. , van den Tweel T. J. J. , de Mul F. F. M. , Greve J. 
Published: May 2005

AbstractA Raman microprobe has been used to measure the surface‐enhanced Raman spectra of adenine, guanine, cytosine and thymine. Comparison of the SERS spectrum with solution spectra shows that some line positions are not influenced by the adsorption process while others show large shifts. In the SERS spectrum new lines, not visible in the solution spectrum, appear while some lines visible in the solution spectrum are not enhanced to a detectable level and are therefore not seen in SERS. The relative intensities are changed owing to an apparently vibration‐dependent enhancement factor. A line‐broadening effect occurs for most lines except carbonyl stretching vibrations in cytosine and thymine. All SERS spectra show increased contributions of bending vibrations and side‐chain groups. In particular, amino group vibrations in adenine and cytosine are clearly visible. Comparison of the shape and intensity of the carbonyl stretching vibrations in cytosine, thymine and guanine show important differences. It is hypothesized that these differences indicate differences in the orientation of these groups with respect to the surface.
Raman spectra of tetrabromophthalic anhydride and its associated charge‐transfer complex, naphthalene‐tetrabromophthalic anhydride
Authors: Kuok M. H. , Looi E. C. , Tang S. H. 
Published: May 2005

AbstractThe low‐frequency Raman spectra of tetrabromophthalic anhydride (TBPA) and its associated charge‐transfer complex naphthalene‐tetrabromophthalic anhydride (N:TBPA) have been recorded at 300 and 77 K. Nine lattice modes are identified for TBPA, the crystal structure of which is found to be unchanged in the range 300–77 K. On complexation, N:TBPA is observed to have a lowest frequency Raman band at 19 cm−1. Neither of its parent molecules have a Raman band with a lower frequency. The 19 cm−1 mode is assigned to the librational motion of the donor (naphthalene) and acceptor (TBPA) molecules of the complex along their stacking axis.
Raman lattice spectra of the tetrachlorides of germanium, silicon, tin and titanium
Authors: Anderson A. , Basista H. T. , Torrie B. H. 
Published: May 2005

AbstractRaman spectra of the lattice modes of the Group IV tetrachlorides GeCl4, SiCl4, SnCl4 and TiCl4 at 20 K are reported. Similarities in the spectra suggest that the crystal structures are identical or closely related. Frequency ratios of corresponding peaks and differences in intensity patterns indicate that coupling between modes of translational and librational origin may be an important factor.
Some interference effects in resonance coherent Raman spectroscopy
Authors: Kircheva P. P. , Simeonov S. D. 
Published: May 2005

AbstractCoherent Raman spectra for resonance pumping conditions and a three‐frequency variant were claculated for polyatomic molecules. A model based on density of states and displaced harmonic oscillators was used. The contributions of different intermediate vibrational levels in the electronic state S1 to the resonance Raman susceptiblity χ and the interference of χ with a non‐resonant electronic background are discussed. It is shown that many intermediate levels belonging to S1 and corresponding to two excited vibrations (the relevant Raman vibration and either one of the others) influence the spectrum significantly, in contrast to the case with absorption. The asymmetry of the Raman line is due mainly to the interference with a non‐resonant background. The method used takes into account the influence of the interference of neighbouring lines on the line shape and also the possible deformation of the lines by the dispersion of the Raman polarizability. The results are in qualitative agreement with known experimental data for some dyes.
Resonance Raman spectrum of the [Cu(HIO6)2]5− anion
Authors: Jubert A. H. , Baran E. J. , Diez A. L. , Sala O. 
Published: May 2005

AbstractThe resonance Raman effect in solid Na5[Cu(HIO6)2].16H2O at room temperature was investigated and the experimental excitation profiles were obtained. From the analysis of the overtone progression of the ν1(A1g) mode, corresponding to the IO symmetric stretching vibration, the X11 anharmonicity constant was determined. The dependence of the Raman intensities on the scattered frequency is briefly discussed.
Solvent dependence of the resonance Raman spectra of azobenzene, 4‐aminoazobenzene, 4‐methylaminobenzene and 4‐dimethylaminoazobenzene
Authors: Barker I. K. , Fawcett V. , Long D. A. 
Published: May 2005

AbstractResonance Raman spectra (RRS) of azobenzene, 4‐aminoazobenzene, 4‐methylaminobenzene and 4‐dimethylaminoazobenzene in the solid state and in a range of solvents have been recorded. The RRS of the 4‐aminoazobenzenes are much more solvent dependent than those of azobenzene. Their electronic absorption spectra suggest that their azo‐nitrogens are strongly hydrogen bonded in aqueous media. The RRS were interpreted in terms of intra‐ and inter‐molecular interactions. These molecules probably have a near‐planar geometry in both the solid state and in aqueous media owing to intermolecular interactions. The intramolecular interactions of the nNN orbitals with the π MOs tend to cause ring twisting about the axis of the NN bond. The RRS of the aminoazobenzenes in non‐polar solvents show differences from that of the powder, and these could only be attributed to the formation of non‐planar structures.
Raman spectra of Br2, Cl2 and I2 on various substrates
Authors: Bernussi A. A. , Gualberto G. M. 
Published: May 2005

AbstractRaman spectra of Br2, Cl2 and I2 adsorbed on graphite, KBr and fused quartz substrates are reported. The results demonstrate that the process of adsorption is strictly related to the type of adsorbate. Different Raman modes were observed for each kind of molecule adsorbed on the substrates. With adsorbed I2, the continuum resonance Raman spectra for the fundamental solid I2 and no frequencies due to adsorption were observed.
Raman spectra of aqueous solutions of formaldehyde and its oligomers
Authors: Möhlmann G. R. 
Published: May 2005

AbstractThe Raman spectra of formaldehyde‐d0 in water‐d0,2 have been recorded. In such solutions formaldehyde is hydrated, thus giving rise to the presence of methylene‐d0 glycol‐d0,2. With increasing concentration, methylene glycol polymerizes yielding soluble and insoluble polyoxymethylene hydrates. By varying the concentration of the solution, the observed Raman transitions could be assigned to vibrations corresponding to the monomer and/or the oligomer hydrates. The Raman spectra obtained for the partly deuteriated molecules permitted improved assignments for the OH bending vibrations and some HCH vibrations.
Surface‐enhanced Raman scattering (SERS) of nucleic acid components in silver sol: Guanine series
Authors: Oh Weon Sik , Kim Myung Soo , Suh Se Won 
Published: May 2005

AbstractThe surface‐enhanced Raman scattering (SERS) of guanine, guanosine, 2′‐deoxyguanosine, 5′‐dGMP, 5′‐rGMP, 5′‐rGDP and 5′‐rGTP adsorbed on aqueous silver sol has been investigated. The peak position and shape of the guanine ring breathing mode are discussed in terms of sugar conformers, the adsorption geometry, the enol‐to‐keto isomerization and the protonation at the N‐7 atom of the guanine base.
Le Système Gazeux Gallium–Chlore: Etude par Spectrométrie Raman. 1–Spectres de Vibration Moléculaire des Espèces Gazeuses: GaCl3, Ga2Cl6, GaCl, Ga2Cl4, Ga2Cl2 et GaCl2
Authors: Hillel R. , Aït‐Hou A. , Berthet M. P. , Bouix J. 
Published: May 2005

AbstractThe molecular vibration frequencies of the gallium–chlorine gaseous species were selected. For the known species Ga2Cl6, GaCl3 and GaCl selection was performed by comparing previous experimental values with our own Raman spectrometric determinations. For the unidentified species Ga2Cl4, Ga2Cl2 and GaCl2 frequency values were evaluated from theoretical literature considerations. The Raman spectra of the vapours obtained by heating condensed gallium and chlorine mixtures are discussed using the selected frequencies and taking into account the Ga2Cl6 and GaCl3 detection limits. With our Raman recording conditions corresponding to well defined spectra, the species are detected up to 5 × 10−3 at. Under these conditions, for Cl/Ga = 3 and between 70 and 500 °C, the main gaseous species are GaCl3 and Ga2Cl6 and the system should be described by the single equilibrium: Ga2Cl6(g)⇌2GaCl3(g). For Cl/Ga = 0.122–3, and between 300 and 800 °C, the representation of the system should be simplified to a single heterogeneous equilibrium between the major species: 2Ga(I)+GaCl3(g)⇌3GaCl(g). In this case, the evolution of the Raman spectra with temperature is explained by taking into account contribution of Ga2Cl4 in very small amounts.
Determination of the secondary structure of proteins from the Raman amide I band: The reference intensity profiles method
Authors: Berjot M. , Marx J. , Alix A. J. P. 
Published: May 2005

AbstractA simple method for determining the quantitative secondary structure of proteins from their Raman spectra, the reference intensity profiles method, is proposed. This uses as a model the Raman spectral intensities of the backbone amide I vibrations (range 1630–1700 cm−1), corresponding to pure classes of secondary conformations, i.e. α‐helical, β‐sheet and undefined structures. The reference intensity profiles were computed by a step‐by‐step fit of the experimental amide I spectra of a large number of proteins, the secondary structures of which were well known from x‐ray diffraction data in the solid state. The method could be of use in determining the secondary structure of a protein in any state. In the case of a protein in solution, the method solves simultaneously for the secondary structural contents and the subtraction coefficient, thus determining the solvent spectral contribution. The proposed method has been applied with success to a large set of proteins. The correlation coefficient between x‐ray data and the Raman calculated results is close to 0.97 for each class of structure, so accurate estimates of secondary structure may be derived by using the reference intensity profiles method.
Raman spectro‐electrochemistry. II. In situ raman spectroscopic studies of the electrochemical reduction of CO2 at cobalt(II) phthalocyanine‐impregnated PTFE‐bonded carbon gas diffusion electrodes
Authors: Masheder D. , Williams K. P. J. 
Published: May 2005

AbstractThe full resonance Raman spectra of cobalt(II) and cobalt(I) phthalocyanine are presented. By comparison with the Raman spectra of similar compounds, it has been possible to assign many of the bands. The resonance Raman spectrum of cobalt(II) phthalocyanine was replaced by that of cobalt(I) phthalocyanine when a PTFE‐bonded carbon gas diffusion electrode impregnated with a small amount of cobalt(II) phthalocyanine was maintained at a potential of −1.80 V, the gas side of the electrode being exposed to a carbon dioxide atmosphere. These results indicate that cobalt(I) phthalocyanine is a reactive intermediate in the electrochemical reduction of carbon dioxide to carbon monoxide at cobalt(II) phthalocyanine‐impregnated electrodes.
Raman spectra of some MIIV2O6 brannerite‐type metavanadates
Authors: Baran E. J. , Cabello C. I. , Nord A. G. 
Published: May 2005

AbstractThe Raman spectra of polycrystalline samples of the metavanadates MIIV2O6 (with M = Ca, Cd, Cu and Mg), belonging to the brannerite structural type, have been recorded. A general assignment, supported by comparisons with known vibrational properties of other oxovanadium species, is proposed. The compounds only give poorly defined IR spectra, which are not useful for the analysis of the vibrational behaviour.
Some model calculations of the resonance background in coherent Raman spectra
Authors: Kircheva P. P. , Simeonov S. D. 
Published: May 2005

AbstractModel calculations of coherent Raman spectra under resonance pumping conditions for polyatomic molecules have been carried out. The influence of the resonance background, which originates from the ‘extra’ resonance term of the resonance vibronic transition S0S1, is demonstrated. According to the calculations, the coherent anti‐Stokes Raman scattering (CARS) spectra for ωa = 2ωp−ωs are slightly changed when the resonance background is taken into account. The background contribution to the coherent Stokes Raman scattering (CSRS) for ωs = 2ωp−ωa is higher. It is shown that a line reshaping associated with the concentration changes contains information about the relaxation parameters of the molecules, especially about the dephasing Γ.
Vibrational study of RbD2PO4 single crystals
Authors: Marchon B. , Novak A. , Blinc R. 
Published: May 2005

AbstractThe Raman (4000–10 cm−1) and infrared (4000–32 cm−1) spectra of RbD2PO4 single crystals were investigated at various temperatures. In the low‐temperature phase, the TOLO splitting expected for a P21 polar space group is not observed in the Raman spectra and the vibrational spectra are consistent with a C2h factor group. The II–III phase transition gives rise to a splitting of some skeletal bending modes and the frequency shift of certain vibrations indicates some displacive be haviour, in contrast to the analogous pseudo‐unidimensional crystal of CsD2PO4. Hydrogen bonding in RbD2PO4 is discussed.
Lattice vibrations of phthalic anhydride
Authors: Colombo L. , Kirin D. , Volovšek V. , Long D. A. 
Published: May 2005

AbstractLow‐frequency polarized Raman spectra of an oriented single‐crystal sample of phthalic anhydride have been recorded and an assignment of observed frequencies has been made on the basis of lattice normal mode calculation performed in the ‘rigid body’ approximation.
Novel cylindrical rotating electrode for anaerobic surface‐enhanced Raman spectroscopy
Authors: Hildebrandt Peter , Macor Kathleen A. , Czernuszewicz Roman S. 
Published: May 2005

AbstractA simple, small‐volume, anaerobic spectroelectrochemical cell for surface‐enhanced Raman spectroscopy (SERS) has been developed which incorporates a large surface area rotating cylindrical electrode design. The cell has been demonstrated to be effective in minimizing photoreduction of light‐sensitive MnIII protoporphyrin.
Assessment of correction procedures for reduction of Raman spectra
Authors: Brooker M. H. , Nielsen O. Faurskov , Praestgaard E. 
Published: May 2005

AbstractRecently it has become apparent that for quantitative studies the I(ω) Raman spectrum measured directly from the spectrometer must be corrected for temperature and frequency factors to give a reduced Raman spectrum, R(ω), which is directly proportional to the intrinsic molar scattering factor. Although generally applicable, the R(ω) spectrum finds its greatest application in the low‐frequency region of hydrogen‐bonded and simple molecular liquids and solids. In this paper the general applicability of the R(ω) format is discussed with respect to the low‐frequency spectra observed for simple molecular and more complicated hydrogen‐bonded liquids and solids. Examples are chosen from S8(s), H2O(I), SO2(g) and SO2(I) and CH3CN(I). Further arguments are presented to stress the need to use temperature‐ and frequency‐corrected band shapes for Raman component bands at non‐zero frequency when attempting to deconvolute the Rayleigh band at zero frequency into component sub‐bands.
Analyse Vibrationnelle et Structurale en Série Aliphatique Saturee. VIII—Spectres de Vibration de l'acide Glutarique et de ses Sels Alcalins en Solution Aqueuse
Authors: Delarbre J. L. , Fabregue E. , Maury L. , Bardet L. 
Published: May 2005

AbstractThe Raman and infrared spectra of glutaric acid, (CH2)3[COOH(D)]2, and its potassium salts, CH2)3(COO2KHD and CH23COO2K2, in aqueous solution have been investigated in the range 3500–200 cm−1. The analysis of the polarization ratio of the Raman lines indicated that glutaric acid belongs to point group C1 whereas its ions belong to point group Cs. An assignment of the fundamental vibrations is proposed.
Observation of no significant surface enhancement of Raman scattering from benzoic acid molecules on mercury
Authors: Wang Shou‐Yih , Chou Shen‐Yuan , Liang N. T. 
Published: May 2005

AbstractThere is controversy regarding the surface enhancement of Raman scattering due to liquid Hg, and the enhancement of benzoic acid molecules adsorbed on liquid Hg has been determined to be essentially zero. However, if the noise error bar is taken into account, the maximum enhancement is estimated to be less than 30. The same enhancement was observed when the temperature was reduced in solidifying liquid Hg.
Raman spectra of crystalline antimony triiodide and arsenic triiodide
Authors: Anderson A. , Campbell J. A. , Syme R. W. G. 
Published: May 2005

AbstractRaman spectra of single crystals of the layered compounds SbI3 and AsI3 at 15K are reported. Polarization measurements allow the eight principal peaks to be classified according to symmetry species. Results of a group theoretical analysis based on both molecular and ionic descriptions of the crystal structure are discussed, and assignments of the observed spectra are proposed. Some ramifications of the more ionic nature of SbI3 on its spectrum are briefly described.
Transform method in resonance Raman scattering with quadratic Franck–Condon and Herzberg–Teller interactions
Authors: Hizhnyakov V. , Tehver I. 
Published: May 2005

AbstractA new method of considering quadratic vibronic interactions and deviations from the Condon approximation in resonance Raman scattering (RRS) is proposed. The method is used for the generalization of the transform law between absorption and Raman excitation profiles, derived earlier for a basic model. In the case of arbitrary mixing of modes with similar frequencies, a simple generalization of the transform law for first‐order RRS is obtained. For an arbitrary change of frequencies without mode mixing the transform law for the nth‐order RRS is given. The equations are valid for an arbitrary number of modes and also take temperature effects into account.
Halogen‐substituted amides. VII—normal coordinate analysis of 2‐fluoroacetamide and 2‐iodoacetamide
Authors: Murthy E. Krishna , Rao G. Ramana 
Published: May 2005

AbstractA 30‐parameter modified valence force field has been employed for a normal coordinate analysis of the in‐plane vibrations of 2‐fluoroacetamide and 2‐iodoacetamide. The force constants have been refined using an overlay leastsquares technique. The potential energy distributions and eigen vectors have been used to make unambiguous vibrational assignments.