bluuebunny/crossref_metadata_2025_split huggingface dataset:
Etude par Spectrométrie Raman de la Transition de Phase Structurale des Tétrachloro et Tétrabromo‐1,2,4,5 Benzenes
Authors: Pasquier B. , Le Calvé N. 
Published: May 2005

AbstractRaman and infrared spectra of crystalline1,2,3,4,5‐tetrachloro‐ and tetrabromobenzenes have been analysed between 10 and 100 cm−1 over a range of temperature from 10 K to 400 K. An assignment of lattice modes is given. The first‐order phase transition is of a displacive type as shown by the behaviour of librational modes. The small value of the estimated β critical exponent in the νT/ν0 = (Tc − T/Tc)β experession is interperted in terms of predominant short‐range interactions in these molecular crystals.
Raman spectra of single crystal s‐trithiane and s‐trioxane. Lattice vibrations
Authors: Thomas Dwaine M. 
Published: May 2005

AbstractThis paper reports the assignments for the lattice vibrations of single crystal s‐trithiane and s‐trioxane, using the Raman scattering technique. For s‐trithiane, spectral measurements were made at 300 K and 30 K; nine bands were observed and assigned. For s‐trioxane, three bands were observed and assigned from 300 K results.
Experimental study of the properties of ZrO2Y2O3 and HfO2Y2O3 solid solutions
Authors: Chistyi I. L. , Fabelinskii I. L. , Kitaeva V. F. , Osiko V. V. , Pisarevskii Y. U. V. , Sil'Vestrova I. M. , Sobolev N. N. 
Published: May 2005

AbstractThe Mandel'shtam‐Brillouin spectra of single crystals of ZrO2–Y2O3 and HfO2Y2O3 solid solutions have been measured and the results explained qualitatively. Using the methods of Mandel'shtam‐Brillouin spectra and ultrasound propagation the elastic and photoelastic constants of single crystals of ZrO2Y2O3 and HfO2Y2O3 solid solutions have been found and their dependence on the composition obtained. The elastic and photoelastic properties of single crystals of these solid solutions are discussed.
Raman and infrared study of the low temperature phase of solid H2S and D2S
Authors: Anderson A. , Binbrek O. S. , Tang H. C. 
Published: May 2005

AbstractRaman, infrared and far infrared spectra of polycrystalline samples of H2S and D2S at 80 K and 18 K have been recorded. Many new features have been detected, including some very low frequency Raman modes. The assignments of these and other peaks are discussed in terms of the known crystal structure and compared with previous results. The spectra are in general compatible with the low symmetry and unusually large unit cell of this molecular crystal. The principal features are described qualitatively in terms of interactions involving the four hydrogen bonds linking each molecule in the two dimeasional network.
Solvent — solute interactions in solutions of mercury(II) halides and halogeno‐complexes in aprotic donor solvents
Authors: Waters D. N. , Kantarci Z. 
Published: May 2005

AbstractRaman spectral data for the species HgX2, HgX3− and HgX42− (X = Cl and Br) in solution in 24 class A donor solvents are presented. The complex ions were present in the solutions as lithium salts. The frequencies (ν1) of the symmetric stretching vibrations of HgX2 and Hg3− correlate well with solvent donicity (DN) and with other measures of solvent donor strength. A two‐parameter regression equation of the form ν1 = ao + a1(DN) + a2(Eτ), where Eτ is the Dimroth‐Reichardt electrophilicity parameter, gives good correlations for the HgX42− ions. Evidence based on (i) the frequency values of the symmetric and antisymmetric (ν3) stretching vibrations of HgCl2 and HgBr2, (ii) the Raman intensities of the ν3 mode of HgBr2 and (iii) the depolarization ratios of the ν1 bands of HgCls and HgBr2 in various solvents, supports the view that these molecules in solution undergo a progressive departure from linearity as a result of increasing solvent coordination to the mercury atom. For solvents of high donor strength (e.g. pyridine), the XHgX interbond angle may approach 120°.
Application of laser Raman multichannel spectroscopy to a kinetic study in the liquid phase
Authors: Crunelle‐Cras M. , Merlin J. C. 
Published: May 2005

AbstractA multichannel spectrometer with photoelectric image devices, interfaced with a data acquisition and handling system, permits temporal analysis of Raman spectra. This system enables rapid kinetic studies to be made. The fast oxidation of sulphite ion by bromate ion in an acid medium (0.46 N) is given as an example. The rate of disappearance of the bromate ion has been determined and shows an important hydrogen ion dependence.
Lattice vibrations of crystalline p‐chloroaniline
Authors: Righini R. , Califano S. 
Published: May 2005

AbstractInfrared and Raman spectra of p‐chloroaniline are reported and assigned for the low‐frequency lattice region at 300 K and 78 K. The observed frequencies of the lattice modes are compared with those calculated using a semi‐empirical intermolecular potential. The agreement is very good, so confirming the high degree of transferability of the atom‐atom potentials. The equilibrium conditions are also well fulfilled by the potential. The total calculated crystal energy is −13.5 kcal mol−1.
Higher‐order Raman spectra of GaP
Authors: Sushchinsky M. M. , Gorelik V. S. , Maximov O. P. 
Published: May 2005

AbstractThe second‐, third‐ and fourth‐order Raman spectra of GaP monocrystals have been investigated, and the relative intensities measured. It is found that the fourth‐order Raman maxima are only a little less intense (about 5 times) than the third‐order ones. Polariton scattering from GaP has also been investigated. It is found that the intensities of polariton scattering and second‐order scattering are similar.
Raman spectra of halate ions as solid solutions in sodium chlorate and bromate lattices
Authors: Fornari B. , Mattei G. , Mattioli L. , Pagannone M. 
Published: May 2005

AbstractThe fundamental vibrational modes of the halate ions as solid solutions in NaClO3 and NaBrO3 lattices have been studied by laser Raman spectroscopy, both at room and at low (80 K) temperature. The four predicted modes have all been observed and assigned for each halate ion. The local symmetry of the doping ions in the host lattices at both temperatures is discussed.
Raman spectrum of gaseous perchloryl fluoride and the deconvolution of bands due to a single isotopic species
Authors: Murphy W. F. , Sunder S. , Katz H. 
Published: May 2005

AbstractThe vapor phase Raman spectrum of perchloryl fluoride has been observed under higher resolution and sensitivity conditions than reported previously, and a temperature study has been carried out for the bands due to the totally symmetric modes. A method has been developed to extract the band due to a single isotopic species from the observed spectrum of a mixture of two isotopic species and applied to the present case. The remaining hot band structure is discussed.
The low frequency spectra of π–σ complexes
Authors: Bobrov A. V. , Kimel'fel'd Ja. M. , Mostovaya L. M. , Mostovoy A. B. 
Published: May 2005

AbstractThe low frequency (30–200 cm−1) Raman spectra of Cl2 and Br2 complexes with ethylene, cyclohexene and benzene have been investigated at 77 K. Vibrations of two types are observed in this region of the spectra for olefin–X2 complexes: valence and probably torsion vibrations.
The temperature dependence of the Raman spectrum of ammonium perrhenate
Authors: Korppi‐Tommola J. , Devarajan V. , Brown R. J. C. , Shurvell H. F. 
Published: May 2005

AbstractRaman spectra of NH4ReO4 and ND4ReO4 have been recorded at several temperatures between 77 K and 353 K. As the temperature is increased, several bands due to both internal and external modes of the perrhenate ion are shifted to lower wavenumbers and there is a discontinuity in the slope of the wavenumber versus temperature curves near 200 K. This behaviour is correlated with recent NQR and X‐ray diffraction results and supports the suggestion of a higher order phase transition near 200 K. The bands due to the ammonium ion vibrations are broadened as the temperature is increased and the librational lattice mode is no longer observable above about 200 K. The nature of the motion of the ammonium ion in the lattice is discussed and it is pointed out that the presence of a librational lattice mode does not necessarily indicate an absence of reorientational motion.
Raman and far infrared spectra and conformation of 1,2‐diiodotetrafluoroethane
Authors: Powell David L. , Gustavsen J. E. , Klaeboe P. , Nielsen C. J. 
Published: May 2005

AbstractRaman spectra of 1,2‐diiodotetrafluoroethane in the liquid and solid states as well as far infrared spectra of the vapour and of a benzene solution have been obtained. These data complement earlier infrared spectra. The compound is shown to exist in the trans conformation in the crystal and as a mixture of trans and gauche conformers in the other phases. Vibrational assignments are made, aided by normal coordinate calculations.
Raman intensities in single crystals of NaPF6·H2O
Authors: Heyns A. M. 
Published: May 2005

AbstractThe Raman spectra of single crystals of NaPF6·H2O are reported. By transferring the Raman tensors for the Oh point group to the NaPF6·H2O crystal, the relative intensities of the PF modes are calculated and a good agreement is obtained between the calculated and observed values. The Raman tensors for the internal modes of the water molecules in NaPF6·H2O are obtained and it is shown why the totally symmetric bending mode of these molecules is not observed in the Raman effect. The ratio of ∂α/∂S1 values for the PF and H2O groups in this study corresponds to the one calculated from a delta potential function.
Association Moléculaire et Paire Ionique dans le Verre et le Liquide du ‘Monohydrate de l'Acide Nitrique’
Authors: Herzog‐Cance M. H. , Potier J. , Potier A. , Dhamelincourt P. , Sombret B. , Wallart F. 
Published: May 2005

AbstractThe Raman spectra of the equimolecular mixture HNO3·H2O in the liquid and glassy states have been investigated in the range 4000–50 cm−1. At least four species have been characterized: (i) The free molecular association H2O…HONO2 νOH(H2O) = 3550 cm−1 (3440 cm−1) and νOH(HNO3) = 2930 cm−1 (2915 cm−1) respectively in the liquid (and the glass). (ii) The free ionic pair (H2OH)+…(ONO2)− that give a splitting (Δν = 170 cm−1) of the ν3(NO) vibration. (iii) Free HNO3 molecules: νNOH = 940 and 950 cm−1 respectively in the liquid and the glass. (iv) The ‘nitric acid trihydrate’: H7ONOνOH between 3100 and 3300 cm−1.
A Raman spectroscopic study of aqueous and methanolic tetramethylammonium chloride solutions
Authors: Kabisch† G. , Klose M. 
Published: May 2005

AbstractPrevious vibrational assignments for Me4N+ are examined and in some respects revised. Frequency and intensity changes in the Raman spectra of Me4NCl solutions with variations of concentration and solvent (D2O and CD3OH) were observed mainly in the CH stretching and NC4 bending regions. These are interpreted in terms of cation‐anion associations the extent of which is found to be much larger in methanolic than in aqueous solution. The effects of temperature on the Raman bands proved to be much smaller than those of concentration or solvent changes.
Ramanspektroskopische Untersuchungen von Zirkoniumtetrachlorid
Authors: Brockner W. , Demiray A. F. 
Published: May 2005

AbstractRaman spectra of crystalline, molten and gaseous ZrCl4 have been measured. The Raman frequencies of the solid have been assigned on the basis of the recently determined crystal structure. In molten ZrCl4 polymeric units with similar structural elements as in the solid and also ZrCl4 molecules will be formed. ZrCl4 molecules are present in the gaseous state.
Etude par Effet Raman des Librations de l'eau dans La2 (SO4)3. 9H2O
Authors: Rull F. , Pastor J. M. , de Saja J. A. , Luu Dang V. 
Published: May 2005

AbstractPolarized Raman spectra of single crystals of La2(SO4)3. 9H2O and La2(SO4)3. 9D2O were recorded from 400 to 800 cm−1. In this region the observed modes were assigned and the librations of water molecules were identified. Potential barrier values were calculated using the V = ½ V0 (1 –cos nφ) potential for the torsional oscillations. Calculations were in complete agreement with the dissociation energy value for the OH…︁O hydrogen bond, evaluated at 25–29 KJ/mol. The frequency shifts and the polarization of the Raman lines of isotopic species allow the correlation of the spectra.
Raman spectra of solid perylene–TCNQ complexes
Authors: Bandrauk A. D. , Truong K. D. , Salares V. R. , Bernstein H. J. 
Published: May 2005

AbstractResonance and pre‐resonance Raman spectra are presented for the 1:1 and 3:1 solid complexes of perylene with tetracyanoquinodimethane (TCNQ). Selective resonance enhancement was observed for perylene. A study of the frequency dependence of the Raman intensities shows that, although these are weak complexes, complexing has a marked influence on the scattering intensities.
Polarized resonance Raman spectra of an oriented diphenylpolyene
Authors: Margulies L. , Stockburger M. 
Published: May 2005

AbstractMeasurements of polarized Raman intensities of partially oriented molecules were shown to be useful for obtaining information about the components of the scattering tensor and the degree of orientation in anisotropic samples. The polarized resonance Raman (RR) spectra of all‐trans‐1,14‐diphenyltetradecaheptaene (DPTH) incorporated in a stretched polyethylene film were studied. The DPTH molecules are highly oriented in the polymer matrix with their longitudinal axis in the direction of stretching. The different components of the scattering tensor for the totally symmetric vibrations of DPTH were determined in the case of resonance excitation. It was found that the diagonal element αzz (z is defined along the polyene chain) gives the largest contribution to the RR intensity. However, the two off‐diagonal elements αzy and αyz also contribute significantly and have different magnitudes. The physical origin of these off‐diagonal elements and of the asymmetry of the scattering tensor are discussed in terms of the vibronic coupling theory.
High resolution Raman spectroscopy of gases with laser sources. XIV—The pure rotational spectra of dimethylacetylene and dimethyldiacetylene
Authors: Thomas P. M. , Weber A. 
Published: May 2005

AbstractThe pure rotational Raman spectra of dimethylacetylene (DMA), dimethylacetylene‐d6 (DMA‐d6) and dimethyldiacetylene (DMDA) vapor excited by the λ0 = 4579 Å,4765 Å,4880 Åand 5145 Å lines of a single mode argon ion laser have been photographed under high resolution. The spectra were recorded on Kodak IIIa‐J spectroscopic plates hypersensitized by baking in nitrogen. The spectra of DMA and DMA‐d6 are those of symmetric top rotors showing the R‐ and S‐branches, whereas in the spectrum of DMDA only the S‐branch is observed. The spectra of DMA and DMA‐d6 were analyzed by including an Hj (J + 3/2)5 term in the frequency formula for the S‐branch, while for DMDA the conventional expression was employed. The results for the molecular constants are, in cm−1,magnified image These constants are average over the ground and excited vibrational states. The quoted errors are five standard deviations. The rCC and rCC bond lengths in dimethylancetylene are related by the expression magnified image.
Raman scattering of hydrogen chemisorbed on silica‐supported nickel
Authors: Krasser W. , Renouprez A. J. 
Published: May 2005

AbstractThe chemisorption of hydrogen on silica‐supported nickel has been investigated by Raman spectroscopy at low temperatures. In the spectral range of 200–2500 cm−1, three systems of vibrational bands are detected. The vibrational bands in the high frequency range at 1999 cm−1 and 2030 cm−1 are interpreted as ṽ(NiH) stretching vibrations of a linear chemisorbed species. At 950 cm−1 a weak broad vibrational band is observed, which is assigned to a multibonded surface species. Two vibrational modes in the spectral range of 600–800 cm−1 result from δ(NiH) deformation vibrations of chemisorbed hydrogen. The spectral data are compared with the vibrational spectrum of chemisorbed deuterium.
The Raman spectrum of the 2200 cm−1 wavenumber region of gaseous ethylene‐d4
Authors: Hegelund Flemming 
Published: May 2005

AbstractThe Raman spectrum of the ν1 and ν5 fundamental bands of ethylene‐d4 has been analysed to yield a number of upper state rotation vibrational constants.magnified image The c‐type Coriolis resonance between the two fundamental bands is discussed.
The totally symmetric rotation‐vibrational Raman bands of benzene
Authors: Jensen Hans Birger , Brodersen Svend 
Published: May 2005

AbstractThe ν1 and ν2 Raman bands of gaseous C6H6 were photographed with a resolution of 0.20–0.25 cm−1. The J structure was resolved, but not the K structure. The analysis yielded several constants, primarily B0 = 0.189751 ± 0.000025 cm−1 (standard error). This number differs significantly from the value obtained by Cabana et al. from the rotational structure of the ν11 infrared band.
The Raman spectra of some hexa‐aquo metal(II) hexafluorosilicate(IV) (M(H)2O)6SiF6) salts between 10 K and 300 K
Authors: Lewis John , Jenkins Tudor E. 
Published: May 2005

AbstractRaman spectra of Ni(H2O)6SiF6, Ni((D2O)6SiF6 and Fe(H2O)6SiF6 have been observed between room temperatures and 10 K, and the measured lines assigned to the various modes of vibration. The spectra of the nickel salts are consistent with R3 symmetry at all temperatures, but below ∼ 230 K the lattice band spectra of the ferrous salt cannot be fitted to R3m or R3, which is consistent with the recent findings that there is a phase transition at about 250 K with the low temperature space group being P21/c. The weakness of the water vibrational bands at room temperature is interpreted in terms of the barrier to 180° flip motion of the water molecules and the coupling of 180° flipping with the water vibrations. The Raman spectrum of polycrystalline Mg(H2O)6SiF6 at 300 K is also given for comparison.
A difference in polarizability between normal and sickle cell oxyhemoglobin as revealed by resonance Raman spectroscopy
Authors: Barrett T. W. 
Published: May 2005

AbstractThis report describes differences in the polarization of the resonance Raman lines at 1317, 1142 and 1012 cm−1 with respect to an exciting wavelength (5730 Å), which is within the long wavelength absorption region, for human normal hemoglobin AA versus sickle cell hemoglobin AS. The evidence indicates that the NCa band region differs in the two hemoglobins. These differences may be related to the differences in dipole moment between normal and sickle cell hemoglobin originally reported by Pauling.1 The usefulness of the resonance Raman technique in providing additional microscopic information in a study of abnormal hemoglobins is discussed.
Raman spectra of halogen‐substituted methanes in the liquid state: Depolarization ratios of the totally symmetric vibration bands
Authors: Fukushi Kohji , Kimura Masao 
Published: May 2005

AbstractPolarized Raman measurements have been made for the totally symmetric vibration bands of a series of halogen‐substituted methanes in the liquid state at room temperature. The effect of polarization mixing due to divergence was examined experimentally and eliminated. The observed systematic variations in depolarization ratio are discussed in connection with the bond polarizability theory.
Spectres de Vibration des Acides Cyclobutane‐1,1 Dicarboxyliques et de Leurs Sels de Potassium en Solution Aqueuse
Authors: Fabrègue Eliane , Cassanas Geneviève , Bardet Lucette 
Published: May 2005

AbstractThe Raman and infrared spectra of 1,1‐cyclobutane dicarboxylic acids 1,1‐CB(COOH)2, 1,1‐CB(COOD)2 and of its potassium salts 1,1‐CB(COO)2 HK, 1,1‐CB(COO)2DK et 1,1‐CB(COOK)2 in aqueous solution have been investigated in the range 3500–200 cm−1. An assignment of the fundamental vibrations is proposed. The analysis of the polarization ratio of the Raman lines has enabled us to conclude that these compounds belong to point group Cs, the cyclobutane ring being puckered.
Resonance Raman spectra of a single crystal linear chain platinum compound, [Pt(en)2][Pt(en)2Cl2](ClO4)4
Authors: Papavassiliou G. C. , Theophanides T. , Rapsomanikis R. 
Published: May 2005

AbstractStrong resonance enhancement of the Pt(IV)Cl stretching vibration of a single crystal of [Pt(II)‐(en)2][Pt(IV)(en)2Cl2](ClO4)4 has been observed with the incident light vector parallel to the linear chain Pt(IV)Cl ⃛Pt(II)(Z). This resonance enhancement is much reduced in the E ⟂ Z spectrum where a normal Raman spectrum is also observed. In agreement with these results the visible reflection spectrum with E‖Z shows a maximum at 435 nm, which is absent with E ⟂ Z.
Aromatic bromination catalysis on zeolites. II—Raman spectroscopic analysis of the reaction of activated Br2 with benzene
Authors: Tsai Peter , Cooney Ralph P. 
Published: May 2005

AbstractRaman spectral evidence indicates that benzene, when reacted with the zeolite adsorption complex MX + Br2, forms a surface donor‐acceptor complex with the adsorbed Br2 on sites III and sites II. At lower Br2 coverage (with sites II occupied and sites III unoccupied) the benzene reacts instantaneously to form addition products.
The pure rotational and vibration‐rotational Raman spectra of 1H3H and 2H3H
Authors: Edwards H. G. M. , Long D. A. , Mansour H. R. , Najm K. A. B. 
Published: May 2005

AbstractThe pure rotational and vibration‐rotational Raman spectra of the hydrogen species 1H3H and 2H3H have been recorded and analysed. The following rotational constants, vibration‐rotational constants and bond lengths were obtained:magnified image The re values are compared with those of 1H2, 1H2H, 2H2 and 3H2 and a weighted mean re value for the hydrogen molecule was calculated.
Raman optical activity: Spectral simulation of the conformer dependent CCl stretching vibrations in 1‐chloro‐2‐methylbutane
Authors: Prasad P. L. , Nafie Laurence A. , Burow Duane F. 
Published: May 2005

AbstractThe atom dipole interaction model for Raman optical activity is utilized to evaluate certain chirality parameters for 1‐chloro‐2‐methylbutane. The necessary normal coordinates and the associated vibrational frequencies for the CCl stretching motion of all nine conformers of this molecule are evaluated. The Raman optical activity spectrum as well as the ordinary Raman spectrum pertaining to CCl stretching vibrations are simulated and compared with the corresponding experimental spectra. Favorable agreement between the calculated and experimental results is obtained except for the overall strength of the ROA spectra where the calculated results are more than an order of magnitude smaller.
Vibrational spectra and normal coordinate analysis of difluorophosphine‐d0 and ‐d1
Authors: During J. R. , Zozulin A. J. , Odom J. D. , Streusand B. J. 
Published: May 2005

AbstractThe Raman and infrared spectra of difluorophosphine and difluorophosphine‐d1 in the gaseous and solid phases from 100 to 3000 cm−1 have been recorded. The six fundamental frequencies have been assigned on the basis of group frequencies, depolarization ratios, band types and isotopic shifts. A normal coordinate analysis was carried out. Very little mixing was found to occur between the normal modes. Thermodynamic functions were calculated from the observed frequencies and previously reported moments of inertia.
A Raman spectroscopic study of methyl ammonium chloride. II—the hydrogen stretching vibrations
Authors: Meinander N. , Bergström G. , Forss S. , Stenman F. 
Published: May 2005

AbstractThe Raman spectra of the three crystalline modifications of eight isotopic species of methyl ammonium chloride and their isotopic solid solutions have been recorded in the temperature range 70–300 K. The CH3 and NH bands in the hydrogen stretching region of the spectra have been identified and an assignment of the CH3 bands is proposed. The large number of methyl bands in the CH stretching region is explained as the result of strong coupling of the symmetric hydrogen stretching fundamental and overtones of the CH3 bending fundamentals. Correlation and crystal field splittings of the bands are also discussed.