bluuebunny/crossref_metadata_2025_split huggingface dataset:
Concentration dependence of Raman linewidth of isopropanol in aqueous solution
Authors: Tanabe Kazutoshi 
Published: May 2005

AbstractThe isotropic Raman linewidth of isopropanol at 818 cm−1 assigned to the CO stretching vibrational mode has been measured at a variety of concentrations in aqueous solution and in nonpolar tetrachloroethylene solution. On the basis of the concentration dependence of the linewidths observed in tetrachloroethylene solution, the isotropic Raman linewidth of the observed line is found to reflect the molarity of the hydrogen bonds of isopropanol. The unusual concentration dependence of the linewidths observed in aqueous solution, which shows a prominent maximum at a low concentration of isopropanol, has been examined in the light of these considerations. As a result, it is concluded that the concentration dependence of the linewidth is well explained in terms of the change in the partial molar volume of isopropanol, reflecting the change in the hydration structure in aqueous solution, and that the isotropic Raman linewidth of isopropanol is determined essentially by hydrogen bonding as an inhomogeneous broadening mechanism, other factors such as the vibrational dephasing being of less significance.
Potential of time‐resolved picosecond interferometry for Raman‐fluorescence discrimination
Authors: Delhaye M. , Deffontaine A. , Chapput A. , Bridoux M. 
Published: May 2005

AbstractPreliminary experiments using Perot‐Fabry interferometers demonstrated the possibility of filtering selectively the fluorescence background from Rayleigh scattering excited by 25 ps pulses. Experiments aimed at extending the technique to spontaneous, Raman scattering are in progress. This technique is compatible with either single‐channel or multi‐channel detection of Raman spectra excited by mode‐locked ion, dye or solid‐state lasers.
Raman lineshape study of the A1 skeletal modes in tert‐butyl chloride
Authors: Friedman B. Ri. , Schwartz M. 
Published: May 2005

AbstractThe polarized and depolarized Raman spectra of the ν6 (CC3 stretch), ν7 (CCl stretch) and ν8 (CC3 bend) modes of tert‐butyl chloride have been studied as a function of temperature in the liquid phase. Isotropic correlation times for the bending mode were found to be 3–4 times longer than values obtained for the two stretching vibrations. An analysis of the isotropic correlation functions using the Kubo lineshape formalism revealed that the less efficient vibrational relaxation of the deformation arises primarily from the lower second monents of this mode. Reorientational times calculated from the two stretching vibrations were almost three times shorter than the earlier reported dipolar relaxation time, indicating that the tumbling motion of tert‐ butyl chloride is close to the small‐step diffusion limit.
Structural study of surface tungstate in WO3Al2O3: Effects of Hydration and 18O Exchange
Authors: Stencel John M. , Makovsky Leo E. , Diehl J. Rodney , Sarkus Tom A. 
Published: May 2005

AbstractThe Raman spectra of a series of WO3AI2O3 catalysts containing 1‐30 wt‐% of WO3 were investigated with respect to the effect of O2 calcination and H2OD2O exposure. These studies showed that the frequencies of bands due to surface tungstate species can be shifted reversibly by as much as 6% of their values during alternate O2 calcination and H2O exposure cycles. The exchange of 18O for l6O in the surface tungstate was also investigated with Raman spectroscopy and ion‐scattering spectrometry. The results were used to assign Raman bands to fundamental vibrations of the surface tungstate and to propose a mechanism of interaction between H2O and the surface tungstate that hitherto has not been addressed for WO3AI2O3.
Vibrational spectra and normal coordinate calculations for some dimethyl sulfide complexes of gold(I) and gold(III)
Authors: Butler Ian S. , Neppel Anton , Plowman Keith R. , Shaw C. Frank 
Published: May 2005

AbstractInfrared and Raman spectra have been recorded at various temperatures for the solld gold (I) and gold (III) coordination compounds (CH3)2 SAuX (X = Cl, Br), (CH3)2 SAuCl3 and their perdeuteriated derlvatives. Vibrational assignments are proposed for the observed bands on the basis of modified Urey‐Bradley force field calculations. The primary force constants, K(Au‐X) and K(Au‐S), are essentially independent of the oxidation state of the gold atom. The data also show that (CH3)2S and (CH3)3P have similar trans‐directing influences in the ground state. The signs of the interaction constants in the square‐planar species, together with the slightly larger trans‐to‐sulfur Au‐Cl stretching force constant in comparison with the corresponding cis value, suggest that the trans‐to‐sulfur Au‐Cl bond is stabilized relative to the cis Au‐Cl bonds by the presence of the (CH3)2S ligand.
Resonance Raman spectra and excitation profiles of tetradesmethyl‐β‐Carotene
Authors: Okamoto Hiromi , Saito Shigeki , Hamaguchi Hiro‐O , Tasumi Mitsuo , Eugster Conrad H. 
Published: May 2005

AbstractResonance Raman spectra of tetradesmethyl‐β‐carotene were recorded using nine laser lines in the visible region. In a KBr disk at 77 K, two strong fundamental bands (1523 and 1133 cm−1) and their overtone and combination bands were observed to the fifth overtone region. Excitation profiles of nine Raman bands, including overtone and combination bands, were measured in isopentane solutions at 185 K. These were simulated by a simple two‐dimensional model based on Albrecht's A‐term, and a reliable set of parameters corresponding to the structure differences between the excited and ground electronic states was determined. The agreement between the observed and calculated excitation profiles was excellent, showing the adequacy of the model adopted.
Brillouin study of the hexagonal—orthorhombic phase transition in LiKSO4
Authors: Young P. W. , Katiyar R. S. , Scott J. F. 
Published: May 2005

AbstractBrillouin spectra of lithium potassium sulfate have been obtained in its hexagonal phase from room temperature to the orthorhombic phase transition temperature at 435°C. The ν11 longitudinal sound velocity corresponding to the C11 elastic coefficient undergoes a smooth decrease with increasing temperature; the maximum decrease is 6.0% at T0=435°C and the temperature dependence of ν11 satisfies an expression of form

with B=(1.13±0.04) × 10−4K−1, C = (0.9±0.1) K and Tc = (467±6)°C=(740±6)K.
Raman spectra of Pb2MoO5 single crystal
Authors: Li‐ji Liao , Qi‐nian Zhang , Peng‐xiang Zhang , Yu‐lung Liu , An Tu 
Published: May 2005

AbstractIn accordance with the crystal structure proposed by Binnie, the principal vibrations of a Pb2MoO5 crystal have been analysed. The symmetry types of all characteristic modes were calculated and the symmetry types of the internal and external vibration modes of the MoO42− and other ions were further calculated by means of factor group analysis. The experimental results are compared with those of the group‐theoretical calculations, and with the Raman lines of PbMoO4 and other Scheelite‐type crystals. The distribution of the spectral lines and their symmetry show the effect of the internal vibrations of the MoO42− ion in a Pb2MoO5 crystal.
Fermi resonance and Raman intensities of carbon disulphide
Authors: Montero S. , Domingo C. , Wetzel F. , Finsterhölzl H. , Schrötter H. W. 
Published: May 2005

AbstractThe gas‐phase Raman spectrum of CS2 has been recorded and analysed in the region of the ν1 : 2ν2 Fermi resonance. The absolute differential Raman scattering cross‐sections and depolarization ratios of the observed vibrational transitions are satisfactorily interpreted in terms of three bond polarizability parameters and the cubic force constant k122.
Raman spectra and vibrational assignments of the molecular adducts PhnPH3–n GaCl3 (n = 1–3)
Authors: Taylor Michael J. , Bohle D. Scott , Riethmiller Stephen 
Published: May 2005

AbstractThe title compounds were prepared and their Raman spectra were measured, assigned and compared with that of PH3GaCl3. The frequencies of the pyramidal GaCl3 unit are sensitive to the basicity of the phosphine ligand. Modes ν(Gap), appreciably coupled to Ph‐P stretching vibrations, are located at 316, 260 and 182 cm−1 as medium to weak bands in the spectra of PhPH2GaCl3, Ph2 PHGaCl3 and Ph3PGaCl3, respectively. The PH stretching and bending modes give rise to medium to strong Raman bands, and these frequencies increase on coordination.
An adaptive detection system for Raman spectral peaks at low signal‐to‐noise ratios
Authors: Dyer Stephen A. , Hardin David S. , Bradley Eugene B. 
Published: May 2005

AbstractRaman spectroscopic techniques have made it possible to study adsorbed species on single metal crystals at submonolayer coverages. However, as the amount of coverage decreases, the signal‐to‐noise ratio (SNR) deteriorates. This paper describes an adaptive peak detector (APD), a data analysis system capable of detecting peaks at low SNRs. The basic APD consists of anadaptive linear predictor (ALP) followed by a variance estimator. This detector is robust in that its performance does not rely on a priori knowledge of the exact signal and noise statistics. An experiment was performed in which single Lorentzian peaks embedded in white Gaussian noise at low SNRs were presented to the APD. A dramatic improvement in the detectability of the peaks is demonstrated; the experimental results indicate that the APD is useful at SNRs as low as 0.3. ALP convergence is shown to be a function of the input variance and the length of the predictor. Practical APD implementation considerations are given, and implications for future studies of adsorbed species are discussed.
Raman and infrared spectra of crystalline methyl iodide
Authors: Binbrek O. S. , Anderson A. , Andrews B. , Torrie B. H. 
Published: May 2005

AbstractRaman and infrared spectra of polycrystalline samples of CH3I and CD3I were recorded at temperatures between 20 K and the melting point, 209 K. No evidence for a solid‐state phase transition was found. New splittings of the internal modes and more complete lattice spectra were observed at lower temperatures. An assignment of all principal bands is proposed, based on the known molecular and crystal structures.
Electronic and vibrational spectra of N‐heterocyclic molecules of biological interest and effect of solvents
Authors: Goel R. K. , Gupta (Km.) C. 
Published: May 2005

AbstractThe infrared and Raman spectra of liquid 2, 4‐dimethoxypyrimidine and solid 6‐chloro‐2,4‐dimethoxypyrimidine and the near ultraviolet spectra of their vapours are reported. An assignment of fundamentals is proposed. Spectra in polar solvents in the UV region are also reported and the effect of solvents is discussed.
Effect of dimerization on Raman intensities: An SCF ab initio study of (HCl)2
Authors: Silvi B. , Allavena M. 
Published: May 2005

AbstractThe intensities of the Raman lines corresponding to the intramolecular stretching modes of (HCl)2 have been calculated from an SCF wavefunction. It is found that the derivatives of the mean polarizability and of the polarizability anisotropy of the proton donor unit are enhanced, while the corresponding properties of the proton acceptor unit remain unaffected. The theoretical intensity ratio is calculated to be 1.69 in qualitative agreement with experiment.
Raman study of the symmetric ν1 vibrational mode of N3− and NO3− in aqueous solutions
Authors: Dean K. J. , Wilkinson G. R. 
Published: May 2005

AbstractThe totally symmetric ν1 vibrational modes of the anions N3− and NO3− have been studied in aqueous solution with very high precision. The effect of different alkali metal cations (Li+, Na+, K+, Rb+ and Cs+) has been systematically recorded as a function of the solution concentration. The experimental results show that the anion ν1 mode frequencies are dependent on both the cation present and on the solution concentration. Extrapolation of the experimental data yielded precise values of the anion ν1 frequencies in the limit of infinite dilution. These frequencies are 1342.7 ± 0.1 cm−1 for N3− and 1047.4 ± 0.1 cm−1 for NO3−. When Li+ or Na+ was present in solution with the azide anion, the ν1 frequency was shifted to a higher value than the infinite dilution frequency, with both cations having approximately the same effect, whereas when K+, Rb+ or Cs+ was present the ν1 frequency was decreased, the largest decrease being caused by Cs+, followed by Rb+, with the smallest decrease being caused by K+. In the case of the nitrate anion, the cations Na+, K+, Li+ and Rb+ were all responsible for an increase in the NO3− ν1 frequency with respect to the infinite dilution value, with the magnitude of the perturbation decreasing from Na+ to Rb+. When Cs+ was present the NO3− ν1 frequency was observed to decrease by a very small amount. It is suggested that for the vibrationally excited azide anion, the cation perturbation occurs through a form of polarizability interaction. However, the cation‐nitrate anion interaction is thought to occur through the effect that the hydrated cation has on the vibrationally excited nitrate anion cosphere of hydration.
Analysis of the resonance Raman spectra of 13C‐and 2H‐substituted carotenoids
Authors: Hayashi Hidenori , Saito Shigeki , Tasumi Mitsuo 
Published: May 2005

AbstractThe resonance Raman spectra of 13C‐ and 2H‐substituted carotenoids were observed from photosynthetic bacteria cultured in 13C‐and 2H‐substituted media, respectively. The observed Raman bands of 13C‐ and 2H‐substituted carotenoids could be reasonably assigned on the basis of the normal coordinate analysis of a model molecule. This gave substantial support to the previous assignments of the Raman and infrared bands of β‐carotene.
Etude par Microspectrometrie Raman de Composes Graphitiques Inseres Par SO3
Authors: Ladjadj M. , Dhamelincourt M. C. , Dhamelincourt P. , Vast P. 
Published: May 2005

AbstractGraphite intercalation compounds are of considerable scientific interest for both applied and fundametal reasons (structural ordering). Micro Raman spectroscopy has been used to investigate graphites intercalated with sulphur trioxide. In these compounds, the E2g2 vibrational layer mode of the graphite lattice shows the known linear frequency dependence with the inverse of the step as observed for many acceptor‐type intercalates. The frequency behaviour of this mode is also indicative of a difference between intercalated graphites prepared with either liquid or gaseous SO3. A study of the Raman spectra as a function of time allowed information on the intercalation kinetics and the ageing of these materials to be obtained.
Infrared, Raman and inelastic neutron scattering study of phase transitions in trimethyloxosulphonium iodide, (CH3)3SOI
Authors: Sourisseau C. , Bee M. , Dworkin A. , Jobic H. 
Published: May 2005

AbstractCalorimetric (DTA), infrared, Raman and inelastic neutron scattering (INS) measurements have been performed for the trimethyloxosulphonium iodide compounds (CH3)3SOI and (CD3)SOI over the range 10–450 K. Two solid‐solid phase transitions were found at about 200 and 250 K and the vibrational study showed that only the low‐temperature crystalline form (III) is completely ordered. From a temperature dependence study of the optical and INS spectra it is concluded that methyl group reorintations are mainly involved in the phase (III)⟷phase (II) transition, while the whole molecule reorientations about the three‐fold axis, partly involved in the phase (II)⟷phase (I) transformation, must be much slower than and decoupled from methyl motions. Finally, the potential barrier height against methyl rotations has been estimated to 13.3 kJ mol−1 from the observed torsional frequencies and compares favourably with the activation energies derived from previous NMR experiments (10.9 kJ mol−1) and from quasi‐elastic neutron scattering results (10.6 kJ mol−1).
Raman and infrared spectra of tetramethylcyclobutane‐1, 3‐dithione and the fully deuteriated derivative
Authors: Shurvell H. F. , Gordon R. D. , Girling R. B. 
Published: May 2005

AbstractRaman and infrared spectra of tetramethylcyclobutane‐1, 3‐dithione (TMCBDT) and the fully deuteriated derivative (TMCBDT‐d12) have been recorded. A reasonably complete set of vibrational frequencies and assignments are presented for the two molecules. The symmetric CS stretching mode was observed at 1328 cm−1 for TMCBDT and at 1352 cm−1 for TMCBDT‐d12. The antisymmetric CS stretching mode occurs at lower frequencies of 1167 cm−1 for TMCBDT and 1158 cm−1 for the deuteriated molecule. This is consistent with previous observations for tetramethylcyclobutanedione. Ground‐state vibrational frequencies of several modes involved in progressions in the n→ π* electronic absorption spectra have been located.
Raman polarizabilities of the ν2, ν5 bands of CD3Cl
Authors: Escribano R. , García Hernández M. , Mejías M. , Brodersen S. 
Published: May 2005

AbstractThe Raman spectrum of the Coriolis interacting ν2, ν5 bands of CD3Cl was recorded with a resolution of ca 0.6 cm−1. Using the vibrational‐rotational parameters of Yamada and Hirota, a computer simulation of the Raman contour was performed, yielding relative values of Raman polarizability derivatives for these bands. By comparison with the absolute intensity measurement of Orza et al., absolute values of the Raman polarizabilities were obtained. The sign of the Raman intensity perturbation was found to be negative.
Electronic, Infrared, Raman and Resonance Raman Spectra of some Hexahalodi(aquo)dimolybdate(II) Anions, Mo2X6(H2O)22−, with Quadruple Molybdenum‐Molybdenum Bonds
Authors: Ceylan V. K. , Sourisseau C. , Brencic J. V. 
Published: May 2005

AbstractThe electronic (800‐400 nm), infrared, ordinary Raman (400‐20 cm−1) and resonance Raman spectra (3000‐20 cm−1) of several hexahalodi(aquo)dimolybdate(II)anions, Mo2X6(H2O)22−, with X = Cl, Br, I, containing quadruple metalmetal bonds were investigated. The electronic spectra of the solid compounds at various temperatures (25, 100 and 300 K) show intense and sometimes structured bands in the visible region (510‐580 nm) assigned to the expected δ → δ* transitions; energy values of the 0 → 0 transition, of the excited‐state metal‐metal stretching vibrational frequency and of the damping factors were thus determined. From the infrared and Raman spectra, the skeletal stretching modes in these binuclear anions have been localized, and from resonance Raman results the ground‐state harmonic frequencies, anharmonic constants, force constants and dissociation energies of the Mo‐Mo bonds have been estimated.Finally, within the Franck‐Condon model for resonance Raman scattering, theoretical and experimental excitation profiles of the metal‐metal fundamental and its first overtone have been compared in order to obtain accurate values of the displacement parameters (Ble ≈︁ 2.78‐2.53) and of the shift in equilibrium positions (Δr1 = 0.13‐0.12 Å); these magnitudes are consistent with other observations and these data represent one of the first quantitative estimates in such systems.
Structure Moléculaire des Dérivés Nitres Aromatiques 5–Spectres de Vibration et Analyse par Coordonnées Normales du 1,3,5‐Triamino‐2,4,6‐trinitrobenzène
Authors: Vergoten G. , Fleury G. , Blain M. , Odiot S. 
Published: May 2005

AbstractLes spectres IR et Raman de 1,3,5‐triamino‐2,4,6‐trinitrobenzène ont été mesurés sur toute la gamme spectrale (10 à 4000 cm−1). Une analyse par coordonnées normales utilisant un champ de force Urey‐Bradley modifié et tenant compte des redondances cycliques permet l'attribution. Les seuls modes purs sont: la torsion CNO2 à 101 cm−1, la torsion CNH2 à 606 cm−1, la déformation angulaire hors du plan NH2 à 1030 cm−1, la déformation angulaire dans le plan NH2 à 1212 cm−1 et les deux déformations de valence NH2 à 3208 et 3308 cm−1.
Phase transition in manganese and zinc fluorotitanate hexahydrate and hexadeuterate systems observed by Raman spectroscopy
Authors: Choudhury P. , Ghosh B. , Patel M. B. , Bist H. D. 
Published: May 2005

AbstractRaman spectra of MnTiF6·6H2O, MnTiF6·6D2O, ZnTiF6·6H2O and ZnTiF6·6D2O single crystals were studied in different polarizations between 300 and 77 K and the observed bands were assigned to the various modes of vibrations of these systems. Phase transition in these systems was observed by studying the intensity of νs(TiF6) mode and νs(H2O/D2O) mode with temperature. The mechanism of the phase transition is discussed.
Orientation of Ru(pyridine)6(BF4)2 at silver electrodes
Authors: Chambers Jeffrey A. , Buck Richard P. 
Published: May 2005

AbstractComparison of Raman spectra of octahedral Ru(pyridine)6(BF4)2 with those of Ru(bipyridine)(pyridine)4(ClO4)2 provides an opportunity to analyse the orientation of Ru(pyridine)6 at silver over a wide potential range. At the more positive potentials, the Ru(pyridine)6 appears to be bonded through two pyridine ligands, while at more negative potentials, the orientation is probably C4ν, indicating bonding through one pyridine. Previously reported potential dependences of Raman scattering intensities show mobility of the complex on the electrode surface and probable conversion between these two orientations. Possibilities for further orientation changes at more positive and more negative potentials are obscured by electrode oxidation and complex desorption, respectively.
Raman and far infrared spectra of solid methyl fluoride, CH3F and CD3F
Authors: Binbrek O. S. , Anderson A. , Torrie B. H. 
Published: May 2005

AbstractFar infrared and Raman spectra of solid CH3F and CD3F have been recorded at 80 and 20 K. The lattice spectra of CD3F and the lattice Raman spectrum of CH3F are reported for the first time. Additional peaks have also been observed in the far infrared spectrum of solid CH3F. New splittings for the internal mode fundamentals for ν3, ν5 and ν6 are reported for both compounds, and also for ν2 (CH3F) and ν4 (CD3F). An assignment of the observed bands is proposed. The crystal structure has not been determined directly, but the spectroscopic evidence suggests that it is centrosymmetric with at least eight molecules in the primitive unit cell.
Surface‐Enhanced Raman scattering spectra of aqueous silver borohydride sols of pyridine and deuterium‐containing pyridines
Authors: Stidham Howard D. , Harris Scott M. 
Published: May 2005

AbstractSurface‐enhanced Raman scattering spectra of aqueous silver horohydride sols of pyridine, pyridine‐4‐d, pyridine‐2,6‐d2 and pyridine‐3,5‐d2 are reported. Depolarization ratios are given as a function of pyridine concentration for a number of pyridine bands over a substantial range of concentrations. Evidence is presented of multiple site adsorption and a new interpretation of these Raman spectra is proposed. The evidence indicates that the surface enhancement derives essentially from the presence of long linear segments of chains of silver spheres in the aggregating sols. The concentration dependence of the depolarization ratios and of the average silver sol particle size show that the depolarization ratio characterizes the extent of dendritic growth of sol aggregates and is thus the same for every Raman band in a given preparation at the same time in the history of its evolution, independent of the rotational characteristics of the sol particles or of the adsorbed pyridine molecules.
Resonance Raman scattering in dyes derived from azobenzene
Authors: Cataliotti R. S. , Murgia S. M. , Paliani G. , Poletti A. , Zgierski M. Z. 
Published: May 2005

AbstractResonance Raman spectra and excitation profiles are reported for six azo dyes in CCl4 solutions through the visible absorption spectrum region. The excitation profiles observed for the five most intense fundamentals in each dye indicate interference between two overlapping electronic manifolds.