bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polar phonons in crystalline glycerol
Authors: Beaudoin Jean Louis 
Published: May 2005

AbstractThe polarized Raman spectrum of some oriented glycerol single crystals have been recorded from 115 to 273 K. The LO–TO splittings have been measured for most of the fundamental vibrations. Some results relating mainly to OH vibrations and lattice vibrations, are presented. Hydrogenbonds appear to be preponderant in intermolecular interactions. A calculation of intermolecular force constants has been performed, which confirms this conclusion.
Laser optical saturation of molecular reorientation in Raman light scattering
Authors: Kielich S. , Ożgo Z. , Wołejko L. 
Published: May 2005

AbstractRaman scattering by molecules and macromolecules, arrayed in the electric field of an intense laser beam, is analyzed. Nonlinear changes in the intensity of light scattered by linear and symmetric‐top molecules are calculated and expressed in terms of even‐order generalized Langevin reorientation functions for all types of Raman‐active vibrations. It is shown that the Raman line intensity can undergo an abatement or an enhancement as a result of reorientation, induced by laser radiation; the analysis of these changes in intensity provides additional information on the Raman polarizability tensor, particularly on the sign and magnitude of its anisotropy.
Raman spectroscopic studies of several phases in the ex‐hen egg lecithin/water system
Authors: Faiman Rosalind , Long D. A. 
Published: May 2005

AbstractRaman spectroscopic studies of egg‐lecithin/water systems over the temperature range −30 to 20°C and water content 1.0 to 30% are reported. It is found that changes in the vibrational Raman spectra can be related to the conformation of the hydrocarbon chains in the various phases of the egg‐lecithin/water systems studied.
A versatile computer‐controlled spectrometer for hyper Rayleigh and hyper Raman spectroscopy
Authors: French M. J. , Long D. A. 
Published: May 2005

AbstractThe construction, operation and performance of a versatile, computer‐controlled spectrometer for the observation of hyper Rayleigh and hyper Raman scattering is described. The instrument may be operated either in a single channel mode using as the detector a photomultiplier, or in a multi‐channel mode using as the detection system a high‐gain image intensifier coupled to a television camera. Typical spectra; obtained with this instrument are presented.
Raman spectra of platinum hematoporphyrin complexes
Authors: Berjot M. , Bernard L. , Macquet J. P. , Theophanides T. 
Published: May 2005

AbstractThe laser Raman spectra of the solid hematoporphyrin free‐base H2Hem, the diacid, [H4Hem]2+ and the platinum complexes, [H4Hem]2+ [PtCI4]2−, the Sitting‐Atop complex (SAT), cis‐Pt(H2Hem) Cl2 and the platino‐hematoporphyrin PtHem have been studied in the range 500 to 1800 cm−1. The spectra of the platinum complexes are significantly different from those of hematoporphyrin and changes of the band profiles upon incorporation of the platinum atom into the porphyrin plane are shown. An interesting change is observed in the series H2Hem → cis‐Pt(H2Hem) Cl2 → PtHem in the region 1300–1650 cm−1. The Raman lines in this region are normally assigned to the vibrational modes of CC and CN. The Raman spectra provide another evidence of the existence of the SAT complex.
Evidence of ion‐pairing in the polarized Raman spectra of a Ba2+CrO doped KI single crystal
Authors: Grzybowski Joseph M. , Khanna R. K. , Lippincott E. R. 
Published: May 2005

AbstractThe polarized Raman spectrum of a dilute solid solution single crystal of Ba2+CrO doped in KI has been obtained. The polarization data confirm the previous assignments based on infrared absorption investigations alone. The Raman polarization measurements strongly indicate the presence of non‐randomly oriented Ba2+CrO ion pairs possessing mainly C2ν and Cs site symmetries.
Preresonance Raman spectra of simple amides using ultraviolet lasers
Authors: Harada Issei , Sugawara Yoko , Matsuura Hiroatsu , Shimanouch Takehiko 
Published: May 2005

AbstractThe Raman spectra of N‐methylacetamide, N‐ethylacetamide, and N‐methylpropionamide have been recoraed using the laser lines at 6471 Å, 4765 Å, 4762 Å, 3507 Å. and 2573 Å for excitation. Appreciable intensity enhancement has been observed for the amide I and III lines in the UV excited spectra; the amide II lines show up clearly in the spectra using 2573 Å excitation, and the G‐methyl and N‐methyl symmetric deformation lines are also enhanced. The possible usefulness of the Raman spectra of peptide molecules obtained using ultraviolet excitation is discussed.
Spectra and structure of organophosphorous compounds. XII:Infrared and Raman Spectra of (CH3)2PH and (CD3)2PH
Authors: Durig J. R. , Saunders J. E. 
Published: May 2005

AbstractThe vibrational spectra of (CH32PH) and (CD3)2PH have been studied and assignments made. In the infrared, the region 4000–33 cm−1 was recorded for the gaseous and solid states whereas the Raman spectra from 3500–10 cm−1 in the gaseous, liquid, and solid states were observed. There is some evidence of weak hydrogen bonding based on the behavior of the phosphorus‐hydrogen stretching and bending modes. There also appears to be considerable interaction between the metnyl rocking and phosphorus‐carbon stretching modes. The a″ and a′ torsional modes appear to be accidentally degenerate at 182 and 142 cm−1 for the ‘light’ and ‘heavy’ compounds, respectively, which gives barriers of 2.14 and 2.30 kcal mole−1, respectively.
Raman scattering of lattice vibrations in H4‐urea and D4‐urea
Authors: Lefebvre J. , Fontaine H. , Fouret R. 
Published: May 2005

AbstractThe five external vibrational modes of h4‐urea and of d4‐urea active in Raman scattering have been measured at room temperature and at 100K. It is shown that the A1 mode has a frequency close to 100 cm−1 at room temperature. It has been possible to interpret the angular dispersion of one of the external polar modes by the dynamical matrix, which has also enabled us to calculate the permanent dipole moment of the molecule of urea. The value obtained, ∼ 3 Debyes at room temperature for h4‐urea and d4‐urea, is accounted for by the hypothesis of ionized hydrogen bonds.
Spectres de diffusion Raman et structure des monocristaux de Mg(H2PO2)2 6H2O et Co (H2PO2)2 6H2O
Authors: Abénoza Michel , Martin Louis 
Published: May 2005

AbstractSingle crystal Raman spectra of Mg (H2PO2)2 6 H2O, Mg (H2PO2)2 and Co (H2PO2)2 6 H2O) were recorded.A complete assignment of the bands to the zero wave vectors modes is proposed. The comparison between calculated and experimental Raman intensities shows the individuality of the H2PO ions in the crystal. Various structure hypotheses are discussed: only the Lopez de Lerma's hypothesis and the 𝒮4 site symmetry for the magnesium (or cobalt) atom are compatible with the Raman spectra data of the three single crystals.
The solid state vibrational spectra of s‐triazine and s‐triazine‐d3 and the monoclinic to rhombohedral phase transition
Authors: Daunt S. J. , Shurvell H. F. , Pazdernik L. 
Published: May 2005

AbstractInfrared and Raman spectra of polycrystalline s‐triazine and s‐triazine‐d3 have been recorded over a wide range of temperatures. The spectra of the high temperature phase are in agreement with predictions based on the reported D3d6 rhombohedral crystal structure. The spectra of the low temperature monoclinic phase are compatible with a unit cell of symmetry C2h with two molecules in Cs or C2 sites. Possible space groups are C2hi; i =1,2,3,4, or 6. The higher order nature of the rhombohedral to monoclinic phase transition is indicated by the gradual increase in splitting of degenerate modes in the infrared and Raman spectra of both C3N3H3 and C3N3D3 as the temperature was lowered. From studies of these splittings up to the phase change, the transition temperature was found to be 200±5K for C3N3H3 and 190±5K for C3N3D3.
Spectres de vibration et structure du nitrate d'uranyle et de rubidium et du sel isomorphe de cesium
Authors: Caville C. 
Published: May 2005

AbstractLes spectres de Raman de monocristaux et les spectres d'absorption IR des poudres sont enregistrés à température ambiante. La fréquence de la vibration antisymétrique de l'ion uranyle est détectée dans les spectres de Raman; ce mode est interdit par les règles de sélection du système trigonal R3C(D). Nous sommes en accord avec une forme pseudotrigonale mais la structure monoclinique C2/m, proposke par rayons X, doit être reconsidérée.
Electronic and vibrational resonance Raman effect of OsBr62− in aqueous solution
Authors: Funato Yoshio , Kamisuki Toshio , Ikeda Ken‐Ichi , Maeda Shiro 
Published: May 2005

AbstractResonance Raman spectra of OsBr ion in aqueous solution were obtained using Ar+ laser exciting lines. Besides the ν1, ν2, and 2ν1 vibrational lines two extremely broad bands were observed at 2740 cm−1 and 4800∼4900 cm−1. The former was definitely assigned to the lowest spin‐orbit level T1g because of its inverse polarization, and the latter depolarized band was attributable to the next lowest T2g and Eg pair, confirming the absorption and luminescence results by Nims et al. Marked resonance enhancement was observed for the electronic and ν1‐vibrational lines in the first absorption region, while only ν1 was enhanced towards the second absorption.
A Raman spectroscopic study of the effect of hydrocarbon chain length and chain unsaturation on lecithin‐cholesterol interaction
Authors: Faiman Rosalind , Larsson Kåre , Long D. A. 
Published: May 2005

AbstractThe effect of cholesterol in equimolar concentrations on five different types of phospholipids in aqueous systems is reported. The phospholipids varied in chain length and chain unsaturation. This investigation confirms that the CH stretching region at 2700–3100 cm−1 is sensitive to conformational changes in the hydrocarbon chains. Moreover, this region of the Raman spectrum shows that small changes in band intensities can be correlated with the effect of the cholesterol on aqueous lecithin system both above and below the chain transition temperature (Tc). The results indicate that cholesterol moderates the change in chain mobility in both directions of the transition liquid crystal⇌gel phase. This effect is larger in lecithins with saturated chains compared to unsaturated chains.
High resolution Raman spectroscopy of gases with laser sources. X. The pure rotational spectrum of borazine
Authors: Kainnady Jakob V. , Weber Alfons 
Published: May 2005

AbstractThe pure rotational Raman spectrum of borazine (B3N3H6) vapor was photographed with a high resolution plane grating spectrograph. Two sets of rotational spectra, each consisting of R‐ and S‐branches, are observed and are assigned to the molecules 11B3N3H6 and 11B210BN3H6 which are concurrently present in a sample containing boron in its natural isotopic abundance. Spectral features which are due to the other two isotopic variants of borazine (11B10B2N3H6 and 10B3N3H6) were not detected. From the observed rotational lines the following constants were determined. For the symmetric top molecule 11B3N3H6, B = 0.175581 cm−1, DJ = 2.36 × 10−8 cm−1 while for the slightly asymmetric top molecule 11B2BN3H6B =1/2(A + B) = 0.177565 cm−1 and Dj = 4.39 × 10−8 cm −1. Since an appreciable number of molecules are in excited vibrational states at room temperature the observed spectra are composites of pure rotational transitions in these excited vibrational states as well as the ground state. The above constants are therefore averages over the ground and excited vibrational states of these molecules. Since resolved spectral features due to 11B10B2N3H6 and 10B3N3H6 were not detected the above constants must also be viewed as averages over these isotopic variants.The B‐value for 11B3N3H6 was calculated using the electron diffraction structures for two suggested models, having C2 and D3h symmetry. These computed B‐values are in disagreement with the observed, spectroscopic B‐value by approximately 1.2%.
The vibrational spectra of mercury (I) bromate, sulphate, and nitrate dihydrate
Authors: Adams David M. , Barlow John , Tan Kang Hai , Taylor Michael J. 
Published: May 2005

AbstractA low‐temperature single‐crystal Raman study of mercury(I) nitrate dihydrate is reported, together with low‐temperature powder Raman and i.r. spectra of the nitrate and of mercury(I) bromate and sulphate. The spectra are given consistent interpretations in terms of factor group analysis. Of note is assignment of ν(HgO) in the 250–265 cm−1 interval for coordinated bromate and sulphate; the demonstration that there is no correlation coupling for ν(HgHg) which consequently appears in the Raman spectra as a single band; and a mercurous ion rotatory mode region ca. 40 cm−1.
Infrared and Raman spectra of CuSO4, 5H2O; CuSO4, 5D2O; and CuSeO4, 5H2O
Authors: Berger J. 
Published: May 2005

AbstractThe Raman spectra of oriented single crystals of Copper (II) sulphate and selenate at 290 K and 150 K are reported and compared. Assignments are proposed for numerous internal modes of the crystals. Raman scattering tensors are calculated for the normal modes of (SO4)2− and (SeO4)2− and compared with experimental results. The structure and the part played by ligands (SO4)2− and (SeO4)2− in these crystals are stated precisely. The molecular complexes Cu(H2O)4 and Cu(D2O)4 are characterized by the assignment of their vibrational frequencies.
Excitation profile study of the resonance Raman effect of Ni (II)‐porphin
Authors: Kamisuki Toshio , Maeda Shiro , Kobayashi Hiroshi 
Published: May 2005

AbstractResonance Raman excitation profiles have been obtained for several non‐totally symmetric fundamentals (A2g and B2g or B2g of D4h symmetry) of Ni(II)‐porphin and some of their overtones in the region of the β absorption band using Ar and Kr ion laser exciting lines. Simulation calculations have been carried out for the observed profiles on the basis of Albrecht's formulation, and thereby vibronic coupling constants between the B and Q states have been evaluated.
Raman scattering of light by magnon‐spin flip excitations in antiferromagnetic semiconductors
Authors: Stasch A. 
Published: May 2005

AbstractEstimates are given for the process by which the s – d exchange interaction may contribute to the Raman scattering due to the magnon–spin flip of the conduction electron processes in antiferromagnetic semiconductors. It is shown that for the typical values of the s – d exchange interaction integral, i.e. 0.01–0.1 eV, the extinction coefficient can be larger by two orders of magnitude than that in ferromagnetic semiconductors. The value of the extinction coefficient in antiferromagnetic semiconductors is found to be 10−9–10−11 cm−1 sr−1. It is also shown that the change of the value of an absorbed energy in an external magnetic field allows us to determine the gyromagnetic factor for the conduction electrons.
Study by Raman spectroscopy of order‐disorder phenomena occurring in some binary oxides with fluorite‐related structures
Authors: Michel D. , y Jorba M. Perez , Collongues R. 
Published: May 2005

AbstractOrder‐disorder phenomena in binary oxides with fluorite‐related structures were studied by Raman spectroscopy.Raman spectra of disordered phases show broad bands, defects leading to selection rule breakdown. For well‐ordered structures, the scattering active modes observed are those allowed by crystal symmetry. Broadening of Raman peaks occurs when order defects are present: antiphase boundaries, distribution of different cations on equivalent crystallographic positions.
Polymorphism in cyclohexanol: A Raman spectroscopic study
Authors: James David W. , Shurvell H. F. , Parry Robyn M. 
Published: May 2005

AbstractRaman spectra of the liquid and three solid phases of cyclohexanol are reported. Disorder in Phase 1 is shown to arise from random mixing of axial and equatorial conformers with free molecule rotation being unimportant. Axial to equatorial transformation is also shown to be unlikely in the solid phase. The equatorial isomer is shown to dominate the structures of phases II and III with phase III showing, in addition, intermolecular hydrogen bonding. The dominant mechanism for dielectric loss in the plastic phase is hydroxyl group rotation with molecule libration playing a minor rôle.
The pulsed laser and gated detection in Raman spectroscopy – a survey of the spectra of common substances including studies of adsorbed benzene
Authors: Yaney Perry Pappas 
Published: May 2005

AbstractA pulsed‐laser Raman spectroscopy system using a doubled Nd: YAG laser is described. Comparisons between spectra recorded using the repetitive mode (low peak power and high duty cycle) with those recorded using the burst mode (high peak power and low duty cycle) are presented showing the degree of discrimination against fluorescence and stray ambient light obtained with a gated detection system. Spectra of nylon, acrylic, benzene with acridine orange, doped SrF2 crystal, and various forms of aluminum oxide and hydroxide are presented. The spectra suggest that the burst mode consistently gives, in all cases, at least a slightly improved Raman‐signal‐to‐noise ratio with some cases showing specular improvement. The results of a preliminary analysis of the Raman spectra of benzene liquid and vapor adsorbed on aluminum oxide/hydroxide powder using the gated burst mode are also presented. Although these spectra were found to differ from that of the liquid, some tentative line identities are offered.
The Raman spectra of (14NO)2 and (15NO)2 solids at 20 K
Authors: Durig J. R. , Griffin M. G. 
Published: May 2005

AbstractThe Raman spectra of (24NO)2 and (15NO)2 have been studied at 20 K. The far infrared of (14NO)2 at 20 K was also measured. The data were assigned on the basis of a C2ν molecular model. Normal coordinate calculations were performed for a variety of assignments. The assignment that yielded the best fit is presented. The solid state effects are discussed.
Resonance enhancement of local modes in the Raman spectra of mixed molecular crystals and biological polymers
Authors: Chen F. P. , Hanson D. M. 
Published: May 2005

AbstractThe effect of electronic resonances on the cross sections for Raman scattering from localized and delocalized vibrational modes is considered for the cases where the resonance is with a localized electronic state and with a delocalized electronic state. It is concluded that resonance with a localized electronic state increases the Raman cross section of the localized mode significantly more than that of the delocalized mode while resonance with a delocalized electronic state has the opposite effect. Furthermore, a coupling of electronic states following a conformational change in a polymer is predicted to decrease the resonance Raman cross section of a localized vibrational mode. Consequently, observations of such effects will serve to identify local phonon modes in mixed molecular crystals and provide information about conformational change in biomolecules.
Raman studies of platinum‐nucleoside complexes
Authors: Theophanides T. , Hadjiliadis N. , Berjot M. , Manfait M. , Bernard L. 
Published: May 2005

AbstractThe laser Raman spectra of a new series of platinum‐nucleoside complexes have been studied in solution at physiological pH values and in the solid state as powders. A qualitative analysis of certain vibrational modes responsible for various spectral lines is given. The carbonyl stretching frequency of guanosine and inosine is only slightly perturbed in the solid state whereas it is not affected at all upon coordination of the metal in water solutions. It is suggested that the binding of the free bases takes place at the Pt‐N7 site in all these complexes.
Weaker spectral features in the Raman spectra of MN3 (M = K, Rb, Cs)
Authors: Ti S. S. , Kettle S. F. A. , Ra Ø. 
Published: May 2005

AbstractThe weaker spectral features in the Raman spectra of MN3 (M = K, Rb, Cs) in the region 1240–1360 cm−1 are reported. The present study indicates that the two‐phonon modes involving ν2 can be analysed solely in terms of k = 0 selection rules whilst the two‐ and three‐phonon bands involving internal and external combination modes require a critical point analysis. There are several possible assignments of a multiphonon band of the latter type; its appearance apparently depends on proximity to an intense fundamental mode, from which it presumably steals intensity.
Spectre Raman et Transition de Phase dans le La2 (SO4)3, 9H2O
Authors: Abenoza Michel , Vinh Luu Dang , Rull‐Perez Fernando , Pastor José Maria 
Published: May 2005

AbstractPolarized Raman spectra of single crystals of La2 (SO4)3, 9H2O and La2 (SO4)3, 9D2 O have been recorded at room temperature and assignments to the zero wave vector modes proposed. Analysis of the spectra shows the non‐individuality of ions and molecules involved in these crystals and the existence of hydrogen bonds of various lengths. The systemiatc temperature study of Raman spectra shows a singularity in the variation of band intensities in the 273–283 K region which confirms the existence of a phase transition at this temperature.
Interference between resonance and preresonance Raman scattering
Authors: Zgierski M. Z. 
Published: May 2005

AbstractThe theory of interference effects between preresonance scattering from an intense electronic transition and resonance scattering from a forbidden electronic transition is formulated. A simple closed formula for the cross‐section of a totaliy‐symmetrical fundamental line is derived for the case where the vibrational structure of both electronic transitions is smeared out. This formula reproduces very well recently obtained experimental excitation profiles in such complex compiunds as tris (ethylenediamine) cobalt (III) chloride and tetrabromopalladate ion.
Spectres Raman de Résonance de la Diéthylcyanine
Authors: Mejean T. , Forel M. T. 
Published: May 2005

AbstractThe resonance Raman spectra of aqueous solutions of the diettylcyanine ion are recorded from 100–4000 cm−1 using all the exciting lines of an Ar+ laser and the 6328 Å line of a HeNe laser. Experimental results, intensities and depolarization ratios, are discussed using Albrecht's theory. The calculated and experimental intensity laws obtained for some normal modes are analysed. An assignment of all the Raman bands is proposed, based upon comparison with infrared spectra and the results of a normal modes calculation.
The resonance Raman spectrum of ClO2. An example of the introduction of morse potentials in the Raman tensor
Authors: Bourgeois M. T. , Jacon M. , Van Labeke D. , Eysel H. H. 
Published: May 2005

AbstractIn this paper, the resonance Raman spectrum of ClO2 in solution, which cannot be quantitatively interpreted within the usual approximations, is described using a Morse function for the nuclear potentials in the lower and upper states. The absorptionspectrum and the Raman excitation profiles are calculated and compared with the experimental results. The study of the depolarization ratio show, a result which cannot be obtained by consideration of the relative intensities.
Absolute Raman intensities of CHCl3 and CDCl3 and force field for chloroform
Authors: Bermejo D. , Escribano R. , Orza J. M. 
Published: May 2005

AbstractThe absolute Raman intensities of the fundamental bands of vapour HCCl3Jand DCCl3 have been measured with an experimental accuracy of ten per cent. The vibrational potential function for chloroform has been calculated by a standard least squares forceconstant refinement including data on anharmonicity corrected values of the 12C/13C displacements and also the absolute intensities measured in this work. The results are compared with those of Previous works and the influence of the intensity data upon the refinement is discussed.