bluuebunny/crossref_metadata_2025_split huggingface dataset:
The shape and width of resonance Raman spectral lines
Authors: Behringer J. 
Published: May 2005

AbstractPresupposing exponentially decaying states (with phenomenological lifetimes) of the particle system interacting with the radiation field, the shape and width of Raman lines is discussed on a quantum‐mechanical basis for the most important types of excitation: non‐resonance, pre‐resonance, rigorous resonance with a continuum level and with a discrete, non‐degenerate, and isolated level; monochromatic and non‐monochromatic irradiation. Attention is called to peculiar intensity distributions of the secondary radiation obtainable by sufficiently monochromatic excitation in near resonance to an isolated state (resonance fluorescence case) which deviate characteristically from those customary in traditional fluorescence and scattering spectra.
Raman intensity and conjugation. IV‐determination of the conjugation between a phenyl ring and a carbonyl group by Raman intensity
Authors: Schmid E. D. , Schlenker P. , Brand R. R. M. 
Published: May 2005

AbstractThe Raman intensities SCO and S8a,b of the CO‐stretching vibration and the 8a, b‐ring vibrations of some compounds of type C6H5‐CO‐X (X = NHNH2, NH2, OC2H5, OCH3, CH3, CH2Cl, H, CL, CF3, CN) have been measured using the excitation lines of an argon ion and a krypton ion laser. The intensities in the two series are linearly related and the (RI)1/2 values correlate both with Hammett substituent parameters and with the extinction coefficients of the longest wavelength u.v. absorption band. The results are interpreted by showing that the intensities here are almost independent of the resonance Raman effect and thus reflect the conjugation effect. Relative Raman intensity values can thus be used to measure the conjugation between a phenyl ring and various carbonyl groups.
Raman scattering investigation of the monoclinic to orthorhombic phase transition in TbP5O14
Authors: Fox David L. , Scott J. F. , Bridenbaugh P. M. , Pierce J. W. 
Published: May 2005

AbstractThe low‐frequency Raman spectrum (6–50 cm−1) of TbP5O14 over the temperature range 300–620 K is reported and the behavior of the soft mode observed, is discussed.
The dependence of Raman intensity on the scattering frequency
Authors: Temperini Marcia L. A. , Sala O. , Bernstein H. J. 
Published: May 2005

AbstractAqueous solutions of (NH4)2MoS4 have been investigated with Ar+ laser excitation, at frequencies which span the visible absorption spectrum. Enhanced values of the anti‐Stokes/Stokes intensity ratios for the fundamental ν1 and overtone 2ν1 show that the Nafie et al. theory accounts satisfactorily for these observed ratios.
Solvent effect on the Raman parameters of the ν (BrBr) band
Authors: Maes Guido , Zeegers‐Huyskens ThéRèse 
Published: May 2005

AbstractThe νBrBr Raman band of bromine dissolved in several organic solvents has been studied. The frequency shift, band width, depolarization ratio and absolute intensity of the band have been determined and discussed in terms of the polarity of the solvent or as a function of specific charge transfer interactions.
Experiments on Raman versus primary light scattering fluxes from pressed discs
Authors: Klosowski J. , Steger E. 
Published: May 2005

AbstractRelative fluxes of transmitted and backscattered Raman (inelastic) and also Rayleigh plus macroscopically (elastic) scattered radiation from powdered samples pressed to discs have been measured as a function of the thickness of the discs. Specular reflection is the biggest source of error and must be avoided in such measurements. The resulting curves are in qualitative accordance with calculations by other authors.
Aromatic bromination catalysis on zeolites. I—Raman spectra of activated adsorbed bromine
Authors: Cooney Ralph P. , Tsai Peter 
Published: May 2005

AbstractLaser Raman spectra of Br2 adsorbed on zeolites X, Y and A reveal features characteristic of physisorbed Br2 and of Br2 on cation oxide sites. Specifically, Br2 on zeolites X adsorbs on sites III (ν(BrBr), 318–280 cm−1) and on sites II (ν(BrBr), 280–240 cm−1). The data indicate that the cations in sites II are more effectively shielded by the oxide framework than those in sites III. The greater participation of the oxide framework in the adsorption at sites II is also reflected in the detection of the adsorbate–adsorbent frequency, ν(O ⃛Br) at ∼ 160 cm−1. The appearance of this line is indicative of significant donor (oxide)–acceptor (bromine) electron‐transfer interaction. The spectra of the adsorption complex NaY + Br2 confirm the assignments for MX + Br2 as NaY has no cations in sites III and fewer cations in sites II than NaX, with the result that only Br2 on sites II (271 cm−1, NaY; 270 cm−1, NaX) and physisorbed Br2 is detected. For NaA, no ν(O ⃛Br) is detected, which is consistent with the previously reported absence of charge‐transfer interactions between the oxide framework and Br2.
Raman study of the influence of conformational structure on the ν1 and ν13 vibrations of the benzene ring in polystyrene and its model compounds
Authors: Jasse B. , Chao R. S. , Koenig J. L. 
Published: May 2005

AbstractThe influence of the chain conformation on the ν1 and ν13 normal modes of the benzene ring in atactic and isotactic polystyrene and their model compounds has been investigated by Raman spectroscopy. The ν1 mode which appears in the 750–800 cm−1 region is influenced as much by the local conformation of the alkyl chain as by the length of the considered conformational structure along the chain. The ν13 mode which appears in the 1195–1215 cm−1 region is only influenced by the local conformation and is insensitive to the length of the alkyl chain.
Infrared and Raman spectral studies of meso‐ 1, 2, 3, 4‐tetrabromobutane and meso‐ 1, 2, 3, 4 ‐ tetrachlorobutane
Authors: Crowder G. A. 
Published: May 2005

AbstractInfrared and Raman spectra were obtained for meso ‐ 1, 2, 3, 4‐tetrabromobutane and meso‐1, 2, 3, 4‐tetrachlorobutane. The spectra of both compounds were interpreted in terms of a centrosymmetrical conformation that has all carbons and primary halogens coplanar, with the secondary halogens being on opposite sides of that plane. Additional conformations are present in solution. Vibrational assignments are proposed, based on approximate normal coordinate calculations.
A Raman spectroscopic study of complexes of thiocyanate at the silver electrode surface
Authors: Gold Harvey S. , Buck Richard P. 
Published: May 2005

AbstractRaman spectra of thiocyanate at the surface of a silver electrode and in a series of aqueous test solutions were compared. The results indicate that spectral variations can be correlated with changes in bonding stoichiometry at the electrode surface as a function of potential.
Analyse Vibrationnelle et Structurale en Série Aliphatique Saturée. II—Spectres de Vibration de l'Acide Succinique et de ses Sels Alcalins en Solution Aqueuse
Authors: Maury Luc , Bardet Lucette 
Published: May 2005

AbstractRaman and infrared spectra of succinic acid (CH2COOH)2, (CH2COOD)2 and its alkaline salts KH(CH2COO)2, KD(CH2COO)2 and K2(CH2COO)2 in aqueous solution have been investigated from 3500 to 400 cm−1; an assignment of the fundamental vibrations is proposed. The analysis of the polarization ratio leads us to conclude that the neutral salt belongs to point group Cs. The acid salt and the acid itself belong to point group C1 and do not exhibit intramolecular bonding.
Spectra and structure of silicon containing compounds. 13—infrared and Raman spectra of 1,1‐dimethyl‐1‐silacyclopentane
Authors: Durig J. R. , Johnson‐Streusand M. 
Published: May 2005

AbstractThe infrared spectra of 1,1‐dimethyl‐1‐silacyclopentane in the vapor and solid phases have been recorded from 4000 to 20 cm−1. The Raman spectra (3500‐0 cm−1) of all phases have been measured and depolarization data have been obtained for both the gaseous and liquid phases. An assignment for the 57 normal modes is presented. The vibrational data are consistent with a twisted ring with molecular symmetry C2. The two low frequency bending modes were observed at 260 cm−1 (radial motion) and 63 cm−1 (puckering motion) but distinct ‘hot band’ transitions were not observed. Thus, the potential functions and the dynamics of the low frequency ring‐bending motions could not be calculated.
Raman difference spectroscopy as a probe of biological molecules
Authors: Rousseau D. L. 
Published: May 2005

AbstractThe application of Raman difference spectroscopy to biological molecules, briefly reported previously,1 is described here in detail. With Raman difference instrumentation frequency differences of less than 0.1 cm−1 in 10 cm−1 wide lines may be reliably detected. The limitation in the ultimate sensitivity for the detection of small differences lies in the signal to noise ratio, the presence of multiple lines and line shape differences. Spectrometer resetability, spectral resolution and step increment size impose no severe restrictions on obtaining small frequency differences. Differences in Raman excitation profiles between two samples may also be examined with this technique, and by making a simple adaptation Raman polarization difference spectra may be studied as well.
Raman scattering from excitons and from photoexcited electrons and holes
Authors: Scott J. F. , Toms D. J. 
Published: May 2005

AbstractRaman spectroscopy has been performed on a variety of ‘hot’ photoexcited electron systems. In p‐type ZnTe large densities of photoexcited electrons can be produced in a steady‐state fashion with only milliwatts of laser excitation well below the bandgap. Spin‐flip Raman scattering from these photoexcited minority carriers is easily detected and is in fact often more intense than the majority carrier transitions. In addition, ‘hot’ hole transitions are observed in the hydrogenic As acceptor series in ZnTe; transitions originating on the 2P5/2 or vibronic 1S3/2 + LO states are observed under similar conditions. These transitions give electron/hole temperatures at several hundred degrees at lattice temperatures of 1.6 K. Raman scattering from photoexcited excitions is observed and analyzed in p‐InSb.
Characteristics of a generalized susceptibility for the analysis of lineshapes of Raman spectra
Authors: Takagi Yasunari , Shigenari Takeshi 
Published: May 2005

AbstractThe characteristics of the generalized Van Vleck‐Weisskopf–Fröhlich type susceptibility (GVWF) are discussed. It is shown that the GVWF can represent both an oscillator type and a relaxational (Debye) type of phonon mode, usually adopted in the analysis of Raman spectra of soft modes in structural phase transitions. It is also shown that a susceptibility for a Ising‐spin system in a transverse field has a close resemblance to the GVWF.
Free radical studies by resonance Raman spectroscopy: Chemically and photochemically generated 1,4‐diaminobenzene radical cation
Authors: Ernstbrunner E. E. , Girling R. B. , Grossman W. E. L. , Mayer E. , Williams K. P. J. , Hester R. E. 
Published: May 2005

AbstractThe free radical cation of 1,4‐diaminobenzene (p‐phenylenediamine, PPD+.) has been generated in aqueous solution, wherein it is short‐lived, by oxidation of the parent compound with bromine. The same PPD+. radical has also been produced by UV photolysis of the parent at 77 K in an ethanolic glassy matrix. Resonance Raman spectra of the radical and its parent are reported and analysed in detail with the aid of normal coordinate and molecular orbital calculations. Evidence is presented for (PPD+.)2 dimer formation in aqueous solution at room temperature.
Free radical studies by resonance Raman spectroscopy: Photochemically generated para‐substituted aniline cation radicals
Authors: Williams K. P. J. , Hester R. E. 
Published: May 2005

AbstractThe free radical cations of a series of para‐ substituted anilines have been formed by UV photolysis of the neutral parent compounds trapped in clear glassy ethanol matrices at 77 K. The radicals all have intense visible absorption bands which facilitate excitation of their resonance Raman spectra. These Raman spectra have been assigned and interpreted in terms of structure changes from the corresponding parents. The changes are shown to correlate well with the appropriate Hammett σp function values for the para‐substituents.
Raman microprobe characterization of urea: n‐paraffin inclusion compounds
Authors: Blaha J. J. , Rosasco G. J. 
Published: May 2005

AbstractUrea:n‐paraffin inclusion compounds have been formed through sonification of urea with pure paraffin liquids. Raman microprobe spectra of individual microcrystals (5–50 μm in size) of these materials are interpreted in terms of a non‐planar conformation for the included paraffins. A series of trans and gauche bonds is shown to yield a conformation of the included alkane that preserves the full symmetry of the hexagonal urea host. The urea host lattice spectrum thereby shows additional sharp bands consonant with a more highly ordered host lattice. These observations are contrasted to the case of the trans‐planar conformation normally encountered and verified in this work for urea:n‐paraffin inclusion compounds prepared from solution.
Laser Raman spectra of potassium sulphamate single crystal
Authors: Raj A. Sundara , Muthusubramanian P. , Krishnamurthy N. 
Published: May 2005

AbstractRoom temperature polarized Raman spectra of potassium sulphamate single crystals have been investigated in the region 30–3400 cm−1 using laser excitation. All lattice modes, excepting two, have been observed. The reassignment of the internal modes of (NH2SO3)− ion has been verified by computing the potential energy distribution. The observed correlation field splitting in KNH2SO3 crystal is very small, of the order of 5–10 cm−1.
Raman and infrared spectra of CH3O(CH2)nOCH3 (n = 3–5) as model compounds of polyethers
Authors: Matsuura Hiroatsu , Murata Hiromu 
Published: May 2005

AbstractRaman and infrared spectra have been measured for CH3O(CH2)n OCH3 (n = 3–5), as model compounds of polyethers [O(CH2)n]m, in the liquid and crystalline solid states. The spectra were analysed on the basis of a normal coordinate treatment. The CH2O stretching vibration is sensitive to the conformation about the CC bond next to the CO bond. The molecular conformations of the model compounds in the crystalline solid state are trans‐gauche‐gauche‐trans for n = 3 and all‐trans for n = 4 and 5. These conformations coincide with the chain conformations of the polymers in the most stable crystal modification. For the model compounds in the liquid state, the gauche conformation about the CC bond next to the CO bond is more stable than the trans conformation.
Fermi resonance of tyrosine and related compounds. Analysis of the Raman doublet
Authors: McHale Jeanne L. 
Published: May 2005

AbstractThe model compound data of Siamwiza et al. on the Fermi resonance doublet of various para‐substituted benzenes is analysed theoretically to obtain the uncoupled frequencies and intensities of the ring breathing mode and the first overtone of the out‐of‐plane bending mode. The possibility of obtaining accurate information on the state of ionization of tyrosine hydroxyl groups in proteins from an analysis of the experimentally observed peak frequencies and intensities is discussed.
Structure of aqueous solutions: Fourier transformation and band component analysis in magnesium nitrate solutions
Authors: James David W. , Carrick Malcolm T. , Frost Ray L. 
Published: May 2005

AbstractThe polarized Raman spectra of aqueous solutions of Mg(NO3)2 have been obtained over the concentration range 0.05 m to 4.0 m. The Fourier transform of the isotropic band profile of the v1 symmetrical stretching frequency of the nitrate ion gives evidence of more than one component. A technique is described to obtain information on the number of component bands and their relative intensities. The bands were subject to component analysis and the results are discussed in terms of three main solution species. The association constant for the formation of solvent separated ion pairs is calculated to be ∼ 2 dm3 mol−1. Evidence is presented for the presence of contact ion pairs at all concentrations above 2 M.
Raman spectral characterization of pure and fluorine‐doped vitreous silica material
Authors: Dumas P. , Corset J. , Levy Y. , Neuman V. 
Published: May 2005

AbstractFluorine doped silica samples have been investigated by Raman spectroscopy. The results obtained allow us to propose a model for dopant incorporation in the silica network, involving the formation of SiO3F tetrahedron. A relationship between the intensity of the ν(Si‐F) stretching vibration band and the refractive index is presented.
Coherent anti‐stokes raman spectra of isoalloxazines
Authors: Müller F. , Vervoort J. , Lee J. , Horowitz M. , Carreira L. A. 
Published: May 2005

AbstractCoherent anti‐Stokes Raman spectra (1700–1100 cm−1) of 7,8‐dimethyl‐10‐tetraacetylisoalloxazine (tetracetylriboflavin) in chloroform and several other solvents of higher polarity and proton availability are reported. Solvent polarity has no influence on either the intensities or frequencies of the Raman modes, whereas the influence of protic solvents is more marked. As well as altering the effective mass of the particular atoms in the isoalloxazine involved, hydrogen bonding is known to change the bond hybridization throughout the entire ring system. A similarly mild electronic perturbation can be produced by changing the methyl substitution on the benzene subnucleus of the isoalloxazine, and this is shown to produce significant changes in the Raman spectrum. Isotopic substitution with 13C and 15N is used to mimic the effective mass changes that would occur on hydrogen bonding. For the model compounds in chloroform, the effect of isotopic substitution on some modes is different from that reported for the same substitution in riboflavin bound to riboflavin binding protein. Frequencies of the prominent bands in all spectra were determined by lineshape analysis. On the basis of these results a tentative interpretation is made of the changes that occur in the Raman spectra of flavins when they bind to flavoproteins.
Étude du Polypropylène Isotactique Étiré Uniaxialement par Effet Raman: Nouveaux Résultats
Authors: Cambon L. D. , Vinh Luu Dang 
Published: May 2005

AbstractOn étudie des échantillons de polypropylène isotactique, étirés uniaxialement à chaud, par effet Raman polarisé. En comparant les divers spectres obtenus, on met en évidence un classement des raies observées selon trois groupes. Reliant ce travail à une étude théorique des tenseurs de polarisabilités dérivées, on définit la hiérarchisation des éléments du tenseur pour chacun de ces groupes. A partir de ces nouveaux résultats, on complète les attributions du polypropylène isotactique faites antérieurement.
Application of the rotational diffusion model to the CARS spectra of high‐temperature, high‐pressure water vapour
Authors: Greenhalgh Douglas A. , Hall Robert J. , Porter Fiona M. , England William A. 
Published: May 2005

AbstractCARS spectra of water vapour at elevated pressures (1–16 bar) and temperatures (300–800 K) have been investigated experimentally and theoretically. A theoretical model of the CARS spectrum of water vapour based on Gordon's rotational diffusion model was tested. The model was adapted to include the effects of vibrational relaxation and dephasing processes. Good agreement was found between experiment and theory for all conditions investigated. Rotational inelastic collisions are dominant and contribute approximately 65% to the overall individual molecular linewidths. As part of the data analysis a new measurement of dσ/dω (H2O)=1.10 × 10−34 ± 20% m2 sr−1 has been made.
Raman and infrared rotation‐vibration spectra of the ν1 Band of D14N3
Authors: Bendtsen Jørgen 
Published: May 2005

AbstractThe rotational structure of the ν1 band of D14N3 in the wavenumber region 2200–2600 cm−1 has been measured by means of Raman spectroscopy with a resolution of 0.3 cm−1. Both components of the hybrid band were observed. In addition, an infrared spectrum of the same wavenumber region was recorded with a resolution of 0.07 cm−1. In the infrared experiment mainly the parallel component was observed. The molecular parameters determined from the observed wavenumbers in the Raman spectrum are (ν0)1=2478.32 (1) cm−1, A1 = −11.096 (1) cm−1,½(B1 + C1)=0.37187 (4) cm−1, (DK)1 = 2.85 (2) × 10−3cm−1 and (HK)0 = 2.7 (4) × 10−6 cm−1. From the infrared spectrum the following values were obtained: (ν0)1 = 2478.451 (3) cm−1, A1 = 11.0902 (4) cm−1, B1 = 0.378186 (9) cm−1, C1 = 0.365032 (9) cm−1, (DK)1 = 2.69 (2) × 10−3 cm−1 in addition to values for (D1)1 and (DJK)1. The discrepancy between the values for (ν0)1 obtained from the two experiments is mainly due to uncertainties in the absolute calibration and to differences in the intensity distributions of the unresolved Q‐branch lines in the two types of experiments.
Raman spectra of NaLa(MoO4)2 single crystal
Authors: Ramakrishnan V. , Dhas G. Arul , Narayanan P. S. 
Published: May 2005

AbstractThe Raman spectra of NaLa(MoO4)2 single crystal have been recorded and interpreted on the basis of C4h symmetry. The observed fundamentals (internal and external) have been assigned unambiguously with the help of polarization data. All the group theoretically predicted Raman active fundamentals have been observed.
Raman and far‐infrared spectra of crystalline methylene chloride
Authors: Anderson A. , Torrie B. H. , Danagher D. J. , Laurin D. G. , White J. K. , Zung W. W. E. 
Published: May 2005

AbstractThe lattice vibrations of crystalline CH2Cl2 and CD2Cl2 have been observed by Raman and far‐infrared spectroscopic techniques. The results are compared with the predictions of group theory, and peaks are assigned on the basis of frequency shifts on deuteration and considerations of intensities, molecular inertia factors and crystal structure.
H2 Raman‐shifted YAG laser ultraviolet Raman spectrometer operating at wavelengths down to 184 nm
Authors: Fodor Stephen P. A. , Rava Richard P. , Copeland Robert A. , Spiro Thomas G. 
Published: May 2005

AbstractApparatus is described for the acquisition of Raman spectra with excitation at wavelengths as short as 184 nm. The H2 Raman‐shifted output of an Nd:YAG laser is directed on to a free‐flowing sample, and the Raman photons are collected and dispersed by a scanning 1.26 m single monochromator equipped with a 2400 groove holographic grating and a solar blind phototube with integrating electronics, or by a 0.5 m spectrograph with an 1800 groove holographic grating and a reticon multi‐channel detector. Data for air‐sensitive samples are obtained by enclosing the sample jet in an inert gas purged shroud equipped with a UV‐transparent optical window. Raman spectra are reported for phenylalanine at a series of excitation wavelengths down to 184 nm. They show a sharp transition between 200 and 192 nm from vibronic to Franck–Condon scattering. At 200 nm, the intensities of the vibronically induced ν8a and ν8b modes, at 1606 and 1586 cm−1, are nearly the same as that of the 1000 cm−1 ν1 ring breathing mode, whereas at 192 nm the relative intensities of the former bands are dramatically dimished. In contrast, the ν8a and ν8b modes of tyrosine continue to show enhancement comparable to the ring breathing modes at 192 nm, the maximum of the strong 1Bα, b tyrosine absorption. The spectrum of insulin at 192 nm shows comparable contributions from tyrosine, phenylalanine and amide vibrations, whereas at 200 and 218 nm excitation the aromatic contributions are dominant.