bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectral theory of molecular rotation‐induced broadening of hyper‐Raman lines in liquids
Authors: Alexiewicz W. , Bancewicz T. , Kielich S. , Ożgo Z. 
Published: May 2005

AbstractThe spectral line shape of hyper‐Raman light scattering in liquids is calculated by the method of irreducible spherical tensors and the theory of rotational Brownian motion. The line broadening due to rotational molecular motion in the liquid is expressed by way of relaxation times τ and is found to depend on nonlinear molecular parameters ∣B̃∣2, which are quadratic functions of the derivatives with respect to appropriate normal coordinates of the hyperpolarizability tensor elements b. Tables of ∣B̃∣2 are adduced for all vibration symmetries of spherical‐top and symmetric‐top molecules. The tensor elements of scattered light intensity are calculated for linearly and circularly polarized incident light. Investigation of hyper‐Raman spectral line broadening is seen as a source of new data on the dynamics of molecules in the liquid state and on their nonlinear optical properties.
Raman spectral studies of cis‐2‐butene‐benzene mixtures
Authors: Lockwood D. J. , Scott J. , Elsdon W. L. , Irish D. E. 
Published: May 2005

AbstractRaman spectra of neat liquid cis−2‐butene and cis−2‐butene‐benzene mixtures, covering the accessible composition range at 20°C and atomospheric pressure, have been obtained. Parameters of the benzene bands at 605.6, 1178 and 991.6 cm−1 and cis−2‐butene bands at 395.5, 871.5 and 1660 cm−1 are reported. Changes in the parameters as a function of concentration are interpreted in terms of a weak dipole‐induced dipole interaction and the consequent effect on rotational motions and resonance energy transfer.
Resonance and preresonance Raman spectra of nucleotides using ultraviolet lasers
Authors: Pézolet Michel , Yu Tain‐Jen , Peticolas Warner L. 
Published: May 2005

AbstractThe Raman spectra of AMP and UMP have been taken as a function of the laser excitation wavelength at 5145 Å, 4880 Å, 4579 Å, 3638 Å, and 2572.5 Å (the first harmonic of 5145 Å). The Raman bands of adenine which decrease in intensity upon base stacking or base ordering are shown to derive their intensity largely from the ultraviolet absorption band at 2600 Å which also decreases in absorption strength upon base stacking or base ordering (hypochromism). These bands show a strong resonance Raman effect (RRE) with 2572.5 Å laser light. These results are in agreement with the suggestion of Tomlinson and Peticolas [1] that Raman hypochromism is largely derived from UV hypochromism. The hypochromic Raman band of uracil at 1230 cm−1 is shown to derive its intensity from the hypochromic UV band at 2050 Å. None of the bands of uracil appear to show RRE when 2572.5 Å laser radiation is used.One or two Raman bands in adenine which are not strongly hypochromic show RRE at 2572.5 Å. These bands appear to come from vibrations which have Raman tensors that derive their intensity from higher UV bands as well as the 2600 Å band.
The 650–1050 cm−1 region of the Raman spectrum of gaseous allene
Authors: Hegelund Flemming , Andersen Helge Blom 
Published: May 2005

AbstractThe rotation‐vibrational Raman spectra of the v4(B1)‐, v10(E)‐ and 2v‐bands of allene‐h4 have been obtained. A ground state combination difference analysis of v10 yields the ground state constants A0−B0 = 4.5147 ± 0.0012 cm−1 and DK0 = (1.12 ± 0.10)·10−4 cm−1. A number of upper state constants for the vibrational levels v4, v9, v10 and v11 are obtained.
Laser excited Raman spectrum of ammonium sulfate single crystal
Authors: Venkateswarlu P. , Bist H. D. , Jain Y. S. 
Published: May 2005

AbstractThe Raman spectra of (NH4)2SO4 single crystals have been recorded and measured using an Ar+ laser as a scource of excitation. The polarization behaviour of the Raman lines in different crystal orientations has been studied. The observed shifts in the range 15–3400 cm−1 have been attributed to the phonons of different symmetry species originating from the internal modes of NH and SO ions and the lattice modes calculated from group theoretical considerations.
Low temperature Raman spectra of NH3SO3 and ND3SO3 single crystals
Authors: Lucazeau G. , Lautie A. , Novak A. 
Published: May 2005

AbstractThe Raman spectra of NH3SO3 and ND3SO3 single crystals at 300 and 30 K have been studied in the 4000 to 5 cm−1 range. Infrared spectra of polycrystalline samples have been recorded for comparison in the 4000 to 60 cm−1 region. Twenty‐three Raman and six infrared lattice modes from respectively twenty‐four and fifteen expected ones have been observed. An assignment in terms of factor group symmetry species, rotational and translational vibrations is given. Static and correlation field splitting of internal vibrations is discussed and an assignment of the bands to group frequencies and molecular and factor group symmetry species is proposed. Torsional vibrations are discussed with respect to the amplitude of this motion and the potential barrier opposed to the rotation of the NH3 group has been determined. The NH stretching frequencies are correlated with the N…︁O distances and the v NH band breadth and structure are discussed.
A Raman spectroscopic study of a single crystal of sodium ammonium selenate dihydrate, NaNH4SeO4·2H2O over the temperature range 293–89 K
Authors: Fawcett V. , Long D. A. , Sankaranarayanan V. N. 
Published: May 2005

AbstractThe Raman spectra of single crystals of NaNH4SeO4·2H2O in various orientations are reported for the temperature range 293–89 K. NaNH4SeO4·2H2O undergoes a transition at 180 K from a paraelectric phase to a ferroelectric phase. The changes in the Raman spectra as the crystal is cooled support the evidence from magnetic resonance studies that the transition is of a displacive type with an associated overdamped soft mode. Ordering of the NH ions but not of the complete crystal occurs at the transition temperature.
A study of the lattice region (0–400 cm−1) of the Raman spectrum of a single crystal of sodium ammonium sulphate dihydrate, NaNH4SO4·2H2O over the temperature range 293–87 K
Authors: Fawcett V. , Long D. A. , Sankaranarayanan V. N. 
Published: May 2005

AbstractThe Raman spectra in the lattice region (0–400 cm−1) of single crystals of NaNH4SO4·2H2O in various orientations are reported for the temperature range 293–87 K. NaNH4SO4·2H2O undergoes a transition at 101 K from a paraelectric phase to a ferroelectric phase. The changes in the Raman spectra as the crystal is cooled support the evidence from magnetic resonance studies that a large lattice distortion occurs at the transition temperature.
Frequency calibration in high‐resolution Raman spectroscopy
Authors: Brodersen Svend , Bendtsen Jørgen 
Published: May 2005

AbstractA technique is described for the frequency calibration of high‐resolution Raman spectra recorded on photographic plates. The frequencies of the Th calibration spectrum are fitted to a calibration polynomial in the observed positions, and the coefficients of this polynomial are determined as functions of the grating angle. For a given calibration the polynomial coefficients are constrained to the values of these functions. In this way the information from all previous calibration spectra is used to improve the accuracy of the calibration of any single exposure. Further, a valuable check is obtained on the overall experimental procedure by requiring the polynomial coefficients to be smooth functions of the grating angle.
A Raman spectroscopic investigation of a single crystal of potassium selenate, K2SeO4 over the temperature range 293–87 K
Authors: Fawcett V. , Hall R. J. B. , Long D. A. , Sankaranarayanan V. N. 
Published: May 2005

AbstractThe Raman spectra in the region 250–1000 cm−1 are reported for six orientations of a single crystal of K2SeO4 over the temperature range 293–87 K. In the spectra of the paraelectric phase at 293 K, splitting of the internal vibrations of the SeO ion is in accord with the predictions of group theory. No significant differences are found in this internal frequency region in the ferroelectric phase at 87K. It is concluded that only minor lattice distortions are occurring at the ferroelectric phase transition which may be associated with a soft mode in the 22 cm−1 region.
Light scattering by polaritons in LiIO3
Authors: Kulevsky L. A. , Polivanov Yu. N. , Poluektov S. N. 
Published: May 2005

AbstractThe results obtained on near forward Raman scattering in LiIO3 by a photographic method are presented. The possibility of observation of the polariton dispersion over the range of the polariton wave vectors up to k = 0 cm−1, resulting from the directional dispersion of the magnitude of wave vector of the incident photons in the crystal is demonstrated. The dispersions of the ordinary and extraordinary refractive indices in this crystal from 2.5 to 10 μ by near‐forward scattering from the upperbranch polaritons are obtained. Our experimental investigations show the intensity dip for polariton frequencies near 1010 cm−1 which is due to lattice‐induced dispersion in the nonlinear susceptibility. Our results indicate that the intensity dip for polariton frequencies around 1600 cm−1, which was observed earlier by Gialorenzi and Tang results from Fermi‐resonance of polaritons with second order phonon lines.
Raman and infrared spectra of solid glyoxal‐d1 and glyoxal‐d2
Authors: Cole A. R. H. , Durig J. R. 
Published: May 2005

AbstractThe Raman spectra of solid glyoxal‐d1 and glyoxal‐d2 have been recorded at −190°C from 100 to 3000 cm−1. Fundamental frequencies of glyoxal‐d2 were observed at 2169, 1709, 1131, 944, 908 and 543 cm−1 and assigned as the CD stretching, CO stretching, CD rocking, CC stretching, CD wagging and CCO bending modes respectively. The infrared spectra of the solids have been recorded from 90 to 4000 cm−1. For C2D2O2 this gives the other six fundamentals at 2177, 1685, 1022, 643, 343 and 174 cm−1. The rule of mutual exclusion holds rigorously showing that the molecule has a centrosymmetric structure in the crystal and that the site is Ci (1). The Raman and infrared spectra of glyoxal‐d1 show many coincidences, confirming the breakdown of the rule of mutual exclusion when the center of symmetry is lost on partial deuteration. Fundamentals are assigned at 2882, 2161, 1720, 1699, 1352, 1116, 1005, 981, 710, 548, 357 and 193 cm−1. The frequency shifts upon solidification are discussed.
Anomalous isotope effect on Raman linewidths in KH2AsO4 and KD2AsO4 crystals
Authors: Laulicht I. , Ofek R. 
Published: May 2005

AbstractExperiment on Raman scattering in KH2AsO4 and KD2AsO4 single crystals in the temperature range of 50–300 K has shown an anomalous isotope effect on the linewidths of a few A1 modes in the 200–900 cm−1 region. The widths in the deuterated crystal are narrowed by a factor of two to four depending on the line and temperature. The behaviour of the proton relaxation time has been obtained as a function of temperature and found to be very similar to those obtained by Lowendes et. al. from the spectral feature of the soft mode. A drastic decrease in the linewidths by a factor of three occurs at the ferroelectric phase transition.
Assignment of the CH stretching vibrational frequencies in the Raman spectra of lipids
Authors: Faiman Rosalind , Larsson Kåre 
Published: May 2005

AbstractA Raman spectroscopic study of several substituted lipids lacking a methyl end group has been carried out in order to assign the vibrational CH stretching modes, all of which arise from the methylene group vibrations. Polarization measurements on the melt and cubic liquid crystalline phase show that the peak in the region of 2885±5 cm−1 is rather weakly polarized in the liquid and liquid crystalline phases, whereas the peak at 2850 cm−1 is rather strongly polarized. Thus it is concluded that the 2850 cm−1 peak arises mainly from the methylene symmetric stretching modes and the 2885±5 cm−1 peak arises mainly from the methylene antisymmetric stretching modes. The band at about 2930 cm−1 is assigned to a symmetric methylene stretching vibration. The implications in the interpretation of chain mobility and chain conformation are discussed.
Ring puckering Raman transitions of trimethylene sulfide and several deuterated analogs
Authors: Wieser H. , Kydd R. A. 
Published: May 2005

AbstractThe Raman spectra of the vapors of several deuterated analogs of trimethylene sulfide in the ring puckering region are reported. Several puckering energy level separations unavailable from the far‐infrared spectra are deduced and compared to values calculated with a quadratic‐quartic potential function. The “best fittingo” potential constants and hence the inversion barriers computed with the new data are virtually the same as those reported previously. For the perdeutero compound one far‐infrared assignment was corrected to fit the Raman data and new values for the potential constants and the barrier were calculated.
On the Raman spectra of solid natural α‐glycine and solid 15N‐substituted α‐glycine
Authors: Stenback Hans 
Published: May 2005

AbstractData on the Raman spectra of natural α‐Glycine and 15N‐substituted α‐Glycine are presented together with details of a computer calculation of the normal vibrations. Assignments are made and compared with previous assignments based on IR measurements.
Raman spectrum and vibrational assignments for tricyclo(3.3.0.02,6) octane
Authors: Baglin Frank G. , Fickes Garry N. 
Published: May 2005

AbstractThe vibrational assignments for the liquid phase of tricyclo(3.3.0.02,6)octane (TCO) are herein presented. Special emphasis was placed upon identification of polarized lines with respect to Fermiresonance interactions. The rigidity of the molecule is discussed.
A Raman spectroscopic study of a vibration‐vibration near resonant energy transfer mechanism in liquid toluene‐d5
Authors: Baglin Frank G. , Whang C. M. 
Published: May 2005

AbstractThe polarized signals from the methyl group stretching coordinate of toluene‐d5 have been analyzed by the time correlation technique. Based upon the polarized signal correlation function of the 2922 cm−1 signal and the presence of Fermi resonance in the molecule, mechanistic interpretations of a vibrational internal conversion process are offered.
Optimierung einer Raman‐Küvette für durchsichtige Proben
Authors: Pilz W. , Kriegsmann H. 
Published: May 2005

AbstractFür viele Streuexperimente an durchsichtigen Substanzen Substanzen (speziell 90°‐Streuung) ist es notwendig, die gesamte Anordung, die aus laserstrahl, Kürvette, Kondensor und Abbildungslinse besteht, zu optimieren. Es wird theoretisch und auch in einer praktischen Näherung nachgewiesen, daß der beste Wert des Energieflusses von der Brennweite des Kondensors abhängt, wenn die Laser‐ und Monochromator‐Parameter fest vorgegeben sind. Die optimale Vergrößerung des Leuchtfadens ist für alle erforderlichen Auflösungen und verschiedene Laser konstant. In Erweiterung der ergebnise anderer Autoren [1–4] fanden wir bei unseren Untersuchungen des Leuchtfaden‐Durchmessers, daß der Einfluß der Beugung vernachlässigt werden kann, wenn der Laserstrahi nicht auf die TEM00‐Mode beschränkt ist.
Raman spectroscopic studies of the various phases of crystalline ammonium fluosilicate (NH4)2 SiF6
Authors: Poulet H. , Mathieu J. P. 
Published: May 2005

AbstractRaman spectra of oriented single crystals of (NH4)2SiF6 are reported for the temperature range 440–20 K. The trigonal phase stable below 278 K undergoes a transition at 38.6 K. The changes in the spectra show that the symmetry does not remain trigonal, but give evidence for a lower symmetry.
Effet de la Liaison Hydrogène sur la Raie Raman ν(CH) de Composés Acétyléniques
Authors: Binet C. , Romanet R. 
Published: May 2005

AbstractThe Raman intensity of the ν(CH) band of 1,5‐hexadiyne has been determined for different states of association; autoassociation of 1,5‐hexadiyne has been comparatively studied by Raman and infrared spectroscopy. The integrated Raman intensity of the ν(CH) band is independant of the state of association within the error limits (⋍10%).
Étude des Effets de Solvant sur l'Intensité de la Raie Raman ν(CC) de l'Octyne‐4 et de l'Octyne‐1: Effets de la Liaison Hydrogene
Authors: Binet C. , Romanet R. 
Published: May 2005

AbstractFrom study of the ν(CC) Raman band of 4‐octyne (a proton acceptor) is is shown that, whenever the solvent is respectively a poor or a good proton donor, the formation of the hydrogen bond increases or decreases the integrated intensity of the band comparatively to pure liquid. From study of the ν(CC) Raman band of 1‐octyne (an electron acceptor) it appears two groups of electron donor solvents: (i) solvents whose effect is compatible with solvent — cage model, (ii) solvents for which the intensity of the ν(CC) band depends of ionization potential, the result suggests a charge‐transfer model.
Stokes and anti‐stokes scattering of light by low‐frequency polaritons in LiIO3
Authors: Kulevsky L. A. , Polivanov YU. N. , Poluektov S. N. 
Published: May 2005

AbstractResults are presented on near‐forward Raman scattering from low‐frequency polaritons in LiIO3 obtained by the photographic method using an iodine filter for attenuation of the laser light before it enters a spectrograph. Our experiment shows that the value of dielectric transition strength of the 238 cm−1 phonon mode measured by Otaguro et al. must be corrected. The clamped dielectric constant (ϵz = 5.9) was determined from polariton measurements at frequencies below the lowest transverse mode. This value is compared with those published elsewhere.
Raman spectra of orthorhombic M2SeO4 (M = K, Rb, Cs) single crystals
Authors: Ti S. S. , Kettle S. F. A. , Ra Ø. 
Published: May 2005

AbstractThe single crystal Raman spectra of orthorhombic K2SeO4, Rb2SeO4 and Cs2SeO4 are reported. Whilst the internal modes experimentally observed are in accord with the factor group prediction, fewer external modes than the predicted are observed.
Spectra and structure of phosphorus‐boron compounds. XV:vibrational studies of substituted P ‐ Hexamethylcyclotriborophosphanes
Authors: Durig J. R. , Sens M. A. , Kalasinsky V. F. , Odom J. D. 
Published: May 2005

AbstractThe infrared spectra (3500−30 cm−1) of solid hexa‐substituted P‐hexamethylcyclotriborophosphanes [(CH3)2PBX2]3 where X = F, Cl, Br, I and CH3 and some corresponding B‐monosubstituted and disubstituted species have been recorded. The Raman spectra (3500−10 cm−1) of the corresponding solids have also been investigated. The vibrational spectra of the hexa‐substituted compounds could best be interpreted on the basis of C3ν molecular symmetry. The observed intermolecular vibrations for these solids indicate little factor group effects. The vibrational spectra of the corresponding B‐monosubstituted compounds were very similar to those for the parent molecules with the addition of three ‘new’ B‐X motions. The molecular symmetries are discussed in relation to a recent nuclear magnetic resonance study.
Structure and conformation of polyriboadenylic acid
Authors: Scovell William M. 
Published: May 2005

AbstractThe Raman spectra of 1.5% polyriboadenylic acid in 0.2 M malonic acid at 15°C and pH 7.2, 5.7 and 5.2 are reported and discussed. Four regions of the spectrum reveal particular aspects of the structure and/or the conformational character of the double‐stranded helix, poly(rA+).
On the force field of cyclopropane
Authors: Robins J. R. , Daunt S. J. , Shurvell H. F. 
Published: May 2005

AbstractRecent data obtained from gas phase Raman spectra of C3H6 and C3D6 has been used to refine the force field of cyclopropane. Values are reported for the interaction constants involving CH2 group vibrations.
Raman spectroscopic studies of chloroprene polymers
Authors: Coleman M. M. , Painter P. C. , Koenig J. L. 
Published: May 2005

AbstractThe Raman spectra of predominantly trans ‐ 1,4‐polychloroprenes are presented. Spectra were recorded of polymers prepared by free radical emulsion techniques in the temperature range −20 to +40°C in both the solid state and in CS2 solution. Spectral changes characteristic of the crystalline and amorphous regions of the polymers have been identified. Measurements of the relative broadness of the 1007 cm−1 Raman line, which is associated with the C‐C stretching frequency in the main chain, have been made and correlated with the amorphous content of the polymer. Extrapolations of these results indicates that polymers prepared in the range 50–60°C should be completely amorphous elastomeric materials.
Laser Raman spectroscopy of biomolecules. X‐frequency and intensity of the phosphodiester stretching vibrations of cyclic nucleotides
Authors: Forrest G. , Lord R. C. 
Published: May 2005

AbstractPhosphate frequencies for eight nucleoside 3′,5′‐ and four nucleoside 2′, 3′‐cyclic monophosphates have been determined by Raman and infrared spectroscopy based on comparisons with modified cyclic nucleotides and model cyclic phosphates. To a first approximation the symmetric diester stretching frequency, νs(OPO), is determined by the OPO bond angle. However, substitution on the phosphate ring also affects the frequency and intensity of νs(OPO). These results are discussed in terms of the use of νs(OPO) to determine the degree of backbone order in polynucleotides.
Rotation‐vibrational Raman spectra of gaseous allene‐1,1‐d2
Authors: Hegelund Flemming 
Published: May 2005

AbstractSeveral rotation‐vibrational bands of gaseous allene‐1,1‐d2 have been studied by Raman spectroscopy and a number of molecular constants are obtained including the ground state constants A0 B̄0 = 2.9520 ± 0.0019 cm−1 and DK = (3.3 ± 0.6) × 105 cm−1. A reassignment of the CD‐stretching vibrations ν5 and ν12 is proposed.
Liaison Hydrogène en Phase Liquide et Spectrométrie Raman II–Amines Primaires et Secondaires
Authors: Perchard C. , Perchard J. P. 
Published: May 2005

AbstractStructure, intensity and depolarization ratio of NH or NH2 Raman bands of some primary and secondary amines have been studied in pure liquid state at different temperatures and in dilute CCl4 solutions. The depolarization ratio and scattering activity, as in the case of alcohols previously studied, increase with self association. It confirms the change of the XH bond polarizability derivatives with hydrogen bond formation.
Matrix isolation Raman spectra of FeCl3 and Fe2Cl6
Authors: Givan A. , Loewenschuss A. 
Published: May 2005

AbstractDistinct Raman spectra of FeCl3 and Fe2Cl6 trapped in solid krypton at 20 K are reported. The spectrum of the monomer consisting of four bands at 460.2 cm1, 363 cm−1, 113.8 cm−1 and 68.7 cm−1 is interpreted in terms of a pyramical C3v molecule. The assignment of these frequencies to ν3, ν1, ν4 and ν2, respectively, as well as the assumption of a non‐planar geometry, differ from a previous infrared study. Force constants calculations and isotope effects support this conclusion. Third‐law thermodynamic functions are calculated. The D2h centrosymmetric geometry of the dimer is confirmed, bond stretching modes assigned and stretching force constants calculated.
Vibrational spectra and normal mode calculations of p‐toluidine and p‐nitrotoluene molecules
Authors: Abasbegović N. , Colombo L. , Bleckmann P. 
Published: May 2005

AbstractRaman and infrared spectroscopic studies of p‐toluidine and p‐nitrotoluene molecules have been performed. In normal mode calculations, the force field has been constructed by the local interaction approximation.
Laser Raman spectra of the complex PtCI3 (9‐methyladeninium)
Authors: Theophanides T. , Berjot M. , Bernard L. 
Published: May 2005

AbstractThe complex PtCI3 (9‐methyladeninium) has been prepared in acidic media and its laser Raman spectrum has been recorded. The spectrum shows small but interesting changes in the vibrations of 9‐methyladenine upon platinum complexation. A comparison of the laser Raman spectra of the free and protonated 9‐methyladenine with that of the complex indicates that platinum coordlnation at N‐7 produces small shift and important perturhathfons of the band intensities of the parine ring vibrations. This result is in agreement with the crystal structure data, which show small local electronic effects when platinum coordinates at N‐7.