bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman study on para nitroaniline single crystal. II: Internal Vibrations
Authors: Harrand M. 
Published: May 2005

AbstractThe assignment of the Raman frequencies from 200 to 1800 cm−1 has been made taking into account the values calculated by Brandmüller et al. for a planar molecule since only the H atoms of NH2 are out of the plane. In the crystal the V line is unusually weak and the 1276–1284 cm−1 broad band is extremely strong: its complexity is explained by a Fermi resonance whose development can be followed with temperature variations. On the other hand the line of the deuterated pNA is always sharp because the resonant combination is related to a NH2 vibration. The observation of this Fermi resonance confirms the non‐planar structure of the molecule in the crystal.
Resonance Raman effect in matrix isolated photolytically produced monomeric iodine: An investigation of the excitation profiles of the overtones
Authors: Grzybowski Joseph M. , Andrews Lester 
Published: May 2005

AbstractHigh intensity resonance Raman overtone progressions out to ν = 3, 14, 23, 24, 25, 17, and 3 have been observed with 457.9 nm, 476.5 nm, 488.0 nm, 514.5 nm, 530.9 nm, 568.2 nm, and 647.1 nm excitation respectively, for monomeric iodine isolated in an argon matrix. The normalised intensities have been determined and plotted as excitation profiles for the overtones. There is substantial evidence indicating a resonance coupling not only with the 3∏Ou+ electronic state of I2, but also with the 1∏1u state. The following spectroscopic constants for matrix‐isolated iodine have been calculated from the wavenumber data: ωe = (213.70±0.22) cm−1, ωeXe = (0.60±0.01) cm−1, and ωeYe = (−0.019±0.002) cm−1.
Indirect coupling of the soft optic phonon in KH2PO4
Authors: Mazzacurati V. , Signorelli G. , Sampoli M. 
Published: May 2005

AbstractThe shape of the low frequency first‐order Raman spectrum of KDP single crystals in the x(y, x)y configuration is discussed. Two and three coupled oscillators models are used to explain the spectral region up to 270 cm−1. The inadequacy of such models in describing the experimentl data is analyzed, and a model in which two optic phonons are coupled via their decay into two acoustic phonons is proposed. The spectra in the para‐electric phase are thus well accounted for by a soft optic phonon interacting via the two‐phonon continuum with a temperature‐independent lattice mode. This picture is found to be consistent with a quite reasonable shape of the joint‐density of states for the acoustic phonons. Finally the proton‐phonon interaction hypothesis is briefly reconsidered from this point of view.
Observation of the accordion band in the Raman spectra of the alkylbenzenes
Authors: Behroozi F. , Priest R. G. , Schnur J. M. 
Published: May 2005

AbstractA study of the Raman spectra of solid and liquid alkylbenzenes was made. The band associated with the accordion mode of the alkyl chain tail was identified in the spectrum of each member of the series studied. A successful model for the dependence of the accordion band frequency on alkyl chain length was developed. Bands associated with kinked alkyl chain conformations were also observed.
The conformational analysis of cis‐3,4‐Dimethylcyclopentanone. I: the vibrational spectra
Authors: Sablayrolles C. , Granger R. , Bardet L. 
Published: May 2005

AbstractThe study of vibrational spectra of cis‐3,4‐dimethylcyclopentanone shows that this molecule belongs to the C1 symmetry group, with a half‐chair conformation.
A method for background light rejection in multiplexed rotational Raman spectroscopy with Fabry–Perot interferometers
Authors: King Robert A. , Smith Wm. Hayden 
Published: May 2005

AbstractThe feasibility of using Fabry–Perot interferometers in the remote sensing of gaseous pollutants via their rotational Raman spectra depends upon the development of a method of rejecting back‐scattered light arising from Mie scattering from dust, Rayleigh, and Raman scattering from the abundant gases in the region being observed. We present measurements of the rejection of Rayleigh and rotational Raman light using Fabry–Perot interferometers in reflection to demonstrate a method of reducing background interference by more than two orders‐of‐magnitude.
Ramanspektren im nahen Infrarot: Ein Vergleich dreier Detektorsysteme
Authors: Nippus Michael 
Published: May 2005

AbstractRaman spectra of various samples, excited by an YAG:Nd‐Laser at 1,06 μm, were recorded by three detection systems. A comparison was made of the detectivity of the infrared‐Raman system against a visible Raman system working at 0,6471 μm.
The polarized Raman and infrared spectra of K2[RuCl5NO]
Authors: Tosi Lucia 
Published: May 2005

AbstractPolarized infrared and Raman spectra of K2[RuCl5NO] and (NH4)2[RuCl5NO] have been obtained and a precise assignment of the four RuCl stretching modes has been made. The lower frequency vibration is unambiguously assigned to the axial RuCl stretch in agreement with previous findings based on substitution of the axial (trans to the NO group) halogen ligand. The results are discussed in terms of Mössbauer data and population analysis.
Raman spectra of gases. XIX–The low frequency gaseous phase Raman spectra and the barriers to internal rotation of the 1,1,1‐trifluoroethyl halides
Authors: Lopata A. D. , Durig J. R. 
Published: May 2005

AbstractThe gaseous phase Raman spectra of CF3CH2I, CF3CH2Br, CF3CH2CI and CF3CH2F have been investigated and the barriers to internal rotation determined. The torsional fundamentals were observed to be unusually strong, depolarized bands, and several Δν = 2 torsional transitions were measured for all compounds. Torsional transitions originating from excited states of the skeletal bend were also observed for CF3CH2CI and CF3CH2F. The torsional barriers found were: CF3CH2I, 4.16 ± 0.11; CF3CH2Br, 4.39 ± 0.07; CF3CH2CI, 4.88 ± 0.03 and CF3CH2F, 3.58 ± 0.14 kcal mol−1.
A computer‐controlled photometer for measuring Raman spectra recorded on photographic plates
Authors: Brodersen Svend , Rasmussen Finn , Bendtsen Jørgen 
Published: May 2005

AbstractThe construction and the operation of a photometer for measuring photographic plates is described. It works fully automatically, controlled by a computer, assigns the comparison spectrum and delivers a microphotometer trace on a linear frequency scale. All the information present on the photographic plate is extracted without the addition of noise to the data. The precision in the determination of the line positions is 0.4 μm.
Single crystal Raman spectra and lattice vibrations of purine
Authors: Bougeard D. , Lautié A. , Novak A. 
Published: May 2005

AbstractThe Raman spectra of a purine single crystal have been studied in the 200 to 5 cm−1 region. Far infrared spectra of oriented needles have been recorded for comparison in the 250 to 15 cm−1 range. Sixteen of the twenty‐one expected lattice vibrations have been observed and asigned to their symmetry species. Normal coordinate calculations for the purine crystal have been carried out, the atom‐atom intermolecular potentials being identical with those of 1,2,4‐triazole with the exception of the H…︁N interaction.
The temperature dependence of the raman effect in some wurtzite type crystals
Authors: Mead D. G. , Wilkinson G. R. 
Published: May 2005

AbstractThe temperature dependence of the one phonon Raman spectra of ZnS (hex.), ZnO and a‐Sic crystals is studied over the temperature range 15 to 1000 K. For ZnS frequency shifts are calculated by Griineisen theory and the k = 0 longitudinal and transverse optic phonon Griineisen parameters determined. The results are compa, indicating that the principal interactions are the cubic anharmonicities. Various calculated properties include the area, second moment, and simulated Raman bands to illustrate the anharmonic behaviour in the solids.
Spectroscopic study of [Me(NH3)6]X2 compounds. I‐Raman study of phase transitions in [Ni(NH3)6](ClO4)2 and [Ni(ND3)6](ClO4)2
Authors: Janik J. A. , Sarga T. , Janik J. M. , Pytasz G. , Sokotowski J. 
Published: May 2005

AbstractTemperature dependence of Raman spectra was measured for polycrystalline [Ni(NH3)6](ClO4)2 and [Ni(ND3)6](ClO4)2. Spectroscopic evidence for the phase transition at 173 K was obtained. The phase transition is evident in the splitting of some bands corresponding to the internal ClOion vibrations and in charactreistic intensity dependences of the bands. Some bands also showed a characteristic broadening with increasing temperature, which we interpret as being connected with stochastic reorientations of NH3 groups and ClOions. Two bands which were not resolved from the others at the room temperature study1 were now evidenced at low temperatures.
Absolute Raman intensities of lattice modes‐investigation of intermolecular interactions in molecular crystals
Authors: D'Orazio M. 
Published: May 2005

AbstractAn investigation has been carried out on the correlation between intermolecular interactions and absolute Raman intensities of lattice modes. The analysis was performed by comparing absolute Raman intensities (measured using crystalline powders) with it could be shown that, in geoerd, the oriented‐gas model is inadequate for the description of the properties of molecular crystals. Large discrepancies in the model could be revealed for modes with both librational and translational character. The discrepancies depend strongly on the intermolecular interactions.
Temperature‐dependent Raman study of H‐bonds and possible phase‐transition in LiHCOO·H2O
Authors: Galzerani José Claudio , Srivastava R. , Katiyar R. S. , Porto S. P. S. 
Published: May 2005

AbstractPolarized Raman spectra of single crystals of lithium formate monohydrate (LiHCOO·H2O) have been measured from 4.2 K to 320 K. In the high‐frequency region, the observed modes have been assigned and the water molecule vibrations identified. The crystallographic distances between the two oxygens involved in the two hydrogen bonds have been obtained from the frequencies of the stretching OH vibrations, and the corresponding O…︁O vibration frequencies have been predicted and identified in the low‐frequency region. Although the crystal is thought to be potentially ferroelectric, we have observed no evidence of any structural change or presence of a ‘soft’ phonon in the crystal in the temperature range studied. Our measurements in various configurations do not indicate the presence of any LOTO splittings or any hydrogen disorder in the crystal.
Spectroscopy study of [Me(NH3)6]X2 compounds. II—Low frequency infrared and Raman spectra at various temperatures
Authors: Zabińaska K. , Janik J. M. , Janik J. A. 
Published: May 2005

AbstractInfrared and Raman spectra of [Ni(NH3)6]X2 compounds were measured at temperatures from 80 K to 300 K in the frequency range below c. 400 cm−1. Besides the simple bands previously reported additional ones were seen, especially at lower temperatures. The broad band which appeared between the lattice vibration and the δ(NNiN) deformation vibration was interpreted as partly representing the phonon density distribution from the whole Brillouin zone. Its appearance is induced by crystal imperfections connected with NH3 vacancies. Additíonal bands between δ(NNiN) deformation vibration and ν(NiN) stretching, and those above the ν(NiN) stretching were interpreted as combination bands in which the lattice vibration combines with the deformation in the former case and with the stretching mode in the latter. A satellite band close to the ν(NiN) stretching was interpreted as a combination of the stretching and libration mode of the whole [Ni(NH3)6]2+ ion. A model correlation function describing the librations was fitted to the experimental correlation function obtained from the i.r. spectra.
Rotation‐vibrational bands of gaseous allene‐d4
Authors: Andersen Helge Blom , Hegelund Flemming , Zangenberg Nina Rothe , Winther Flemming 
Published: May 2005

AbstractMany of the fundamental bands of allene‐d4 have been analysed to yield a number of molecular constants, including the ground state constants Ao — Bo = 2.1832 ± 0.0004 cm−1 and Dko = (2.8 ± 0.2) × 10−5 cm−1. A reassignment of the perpendicular bands ν8 and ν11 is proposed.
Raman spectra of gases. XXI—bis(trifluoromethyl)peroxide
Authors: Durig J. R. , Bucy W. E. , Natter W. J. 
Published: May 2005

AbstractThe Raman spectra of gaseous and solid bis(trifluoromethyl)peroxide, (CF3)2O2, have been recorded from 20 to 1300 cm−1. The infrared spectrum of the solid has been investigated from 35 to 1300 cm−1. The far infrared spectrum of the gaseous phase was recorded from 20 to 250 cm−1. A reassignment of the low frequency fundamentals has been made. Both CF3 torsional modes have been observed in the solid and at least one in the gaseous phase. The barrier to internal rotation of the CF3 top has been calculated to have a value of 0.73 kcal mol−1 in the gaseous phase.
Étude par Spectroscopie Raman du Mouvement Orientationnel des Molécules de Chlore à l'État Liquide
Authors: Viossat Gérard , Cavagnat Raymond , Lascombe Jean 
Published: May 2005

AbstractLes spectres Raman isotrope et anisotrope du chlore liquide ont été enregistrés à différentes températures. On montre que la convolution du profil isotrope par un profil lorentzien de largeur convenable permet de retrouver avec une très bonne approximation le profil anisotrope expérimental. Selon la théorie de Bratos et de ses coll., ce profil lorentzien est dǔ aux mouvements de réorientation des molécules de chlore dans le liquide; on en déduit le temps de corrélation et la constante de diffusion rotationnelle. Ces résultats sont comparés aux résultats antérieurs obtenus par résonance magnétique nucléaire et la dynamique rotationnelle des molécules de chlore est discutée.
Solid state studies. XII—the vibrational spectra of mixed crystals of (C6H5)3PMxM′1‐x(CO)5 where M, M′ = Cr, Mo, W
Authors: Kariuki David N. , Kettle Sidney F. A. 
Published: May 2005

AbstractThe high molecular symmetry (C4ν) and single crystal structure (P1,, Z = 2) of the title compounds permit an analysis of their vibrational spectra in the 2000 cm−1 region in terms of modal behaviour. This analysis is confirmed by spectral measurements on mixed crystals.
Temperature dependence of the Raman spectra of NaClO4 in relation to the 581 K phase transition
Authors: Toupry‐Krauzman N. , Poulet H. 
Published: May 2005

AbstractThe evolution of the internal and external modes in the Raman spectra of NaClO4 has been studied in the neighbourhood of the transition temperature, at 581 K. Large changes in the frequencies of the external modes with temperature have been observed. These changes can be explained in terms of a model based on the reorientation of the perchlorate ions.
Raman intensities of charge transfer complexes of benzene and halogen molecules
Authors: Abe H. , Ito M. 
Published: May 2005

AbstractThe Raman spectra of solid complexes formed between halogens as electron donors and benzene and methylated benzenes as electron acceptors were measured at 77 K. Great increase in intensity was observed for the Raman lines ν10(e1g), ν16(e2u) and ν17(e2u) of benzene on complex formation. The great intensity enhancement of these out‐of‐plane bending modes is reasonably explained as the result of mixing of the 1A2u (σπ*) state of benzene and the charge transfer state. The observed spectra are consistent with the crystal structure of factor group C3ν, having one halogen molecule and one benzene molecule in a unit cell, which was proposed by Person et al. from the infrared spectra. It was found that the Raman spectra of the complexes provide a good test for the Raman intensity mechanism proposed for benzene and also give important information about electronic excited states which are not identifiable by other means.
On the Raman spectrum of a single crystal of K2SeO4: Corrections to earlier spectra and assignments
Authors: Caville C. , Fawcett V. , Long D. A. 
Published: May 2005

AbstractImproved room temperature Raman spectra obtained from oriented single crystals of K2SeO4 of high quality are reported and discussed. The new results show that some of the earlier spectra contained spurious bands and that some genuine bands were incorrectly assigned.
Etude par spectroscopie Raman de l'influence de la pression sur l'association de l'ion thiocyanate avec divers cations metalliques en solution aqueuse
Authors: Manouvrier E. , Devaure J. 
Published: May 2005

AbstractUsing Raman spectroscopy we have investigated the effect of pressure on the association between the thiocyanate ion and some metallic cations: Zn2 +, Mn2 +, Al3 +, In3 +, Th4 +, Hg2 +. The ν(CS) stretching vibration of the anion has been analysed because of its sensitivity to the complexation; new ν(CS) lines appear at frequencies well distinct from that of the free ν(CS). The quantity of free SCN− has been determined from the intensity of the free ν(CS) line and has been used to calculate the formation constants for the equilibria Mx + + nSCN−⇄M(SCN). Values have been obtained at normal pressure and at 3000 atmospheres. Finally, the mean value of the change of the partial molal volume Δ V for the complexation reaction between the two extreme pressures has been calculated. The dissociation of the complexes is generally favoured by an increase of the pressure, and the Δ V values are positive. We think that the largest measured values of Δ V are due to a change of the coordination number of the cation on complexation.
Polarization properties of coherent anti‐stokes Raman spectra (CARS) in isotropic liquids
Authors: Nestor J. R. 
Published: May 2005

AbstractLinearly polarized excitation has been used to obtain CARS and CSRS spectra of some simple liquids and of cytochrome C in dilute solution. The data are described in terms of the depolarization ratio of conventional Raman spectroscopy. The symmetry properties of the third‐order susceptibility are shown to be maintained under conditions of electronic resonance.
Etude par spectroscopie Raman Du Chlorure Tetraammine Platine(II) et Dérivé Deutérie
Authors: Manfait M. , Alix A. J. P. , Bernard L. , Theophanides T. 
Published: May 2005

AbstractThe Raman spectra of the platinum complex [Pt(NH3)4]Cl2 and [Pt(ND3)4]Cl2 in the solid state and in aqueous solution and of [Pt(NH3)4]Cl2·H2O in the solid state have been obtained and discussed. All the ligand vibrations in the deformation and rocking regions have been studied and some show interesting changes on hydration. The polarization data and high quality spectra obtained in this study allow a more complete assignment of the vibrational modes of the complex.
Effects of hydrogen bonding on the Raman intensities of methanol, ethanol and water
Authors: Abe Naomichi , Ito Mitsuo 
Published: May 2005

AbstractThe absolute Raman intensities of methanol, ethanol and water in the gas and liquid phases have been measured using 514.5 and 337.1 nm excitation. Large intensity changes were observed for the Raman lines of the OH stretching vibrations in changing from gas to liquid. The observed intensity changes are interpreted as due to the additional contribution of the charge transfer electronic excited state arising from hydrogen bond formation. The Raman intensities of methanol, ethanol and water in alkali halide solutions were also studied. The observed effects of halide ions on the intensities and their excitation wavelength dependences were found to be well correlated with the known charge transfer states resulting from electron transfer from the halide ion to the surrounding solvent molecules.
Vibrational spectra of 1,5‐cyclooctadiene, di‐μ‐chlorobis[(1,5‐cyclooctadiene)rhodium(I)], di‐μ‐chlorobis[(1,5‐cyclooctadiene)copper(I)] and bis(1,5‐cyclooctadiene)copper(I) perchlorate
Authors: Barna Gabriel G. , Butler Ian S. 
Published: May 2005

AbstractThe vibrational spectra of 1,5‐cyclooctadiene (C8H12, COD) and the rhodium(I) and copper(I) complexes, [(COD)RhCl]2, [(COD)CuCl]2 and (COD)2CuClO4, have been investigated. In the liquid state, COD exists in a C2ν ‘tub’ configuration; the same structure is apparently also preserved in the solid at −196°C. The spectra of the dimeric complexes are in accord with the known D2h molecular symmetries and assignments for the ν(CC), ν(MCl) and ν(M—olefin) vibrations are proposed accordingly. The spectra of (COD)2CuClO4 indicate the presence of a non‐bonded olefinic group and a three‐coordinate structure is proposed for the (COD)2Cu+ ion.
Etude de la Dynamique Orientationnelle des Molécules d'Allène a l'Etat Liquide par Spectrométrie Raman
Authors: Bouachir M. , Lascombe J. 
Published: May 2005

AbstractThe orientational dynamics of liquid allene has been studied by means of the analysis of the isotropic and anisotropic profiles of the symmetrical A1 band at 1074 cm−1 and of the anisotropic profile of an E band at 3067 cm−1. These profiles have been studied in the temperature range from 300 to 150 K and for pressures ranging from 100 to 3000 atm.Using the hypothesis of a diffusional rotation, the analysis of the former band allows the determination of the principal component D⊥ of the diffusion tensor, as well as of the associated activation energy and activation volume. The comparison of the observed orientational correlation times with the free‐rotation times and the shape of the correlation functions are not in too bad agreement with this hypothesis. The second band of E symmetry, which corresponds to a vibration whose Coriolis constant is very small, allows the evaluation of the diffusional Constant D∥ associated to the rotation of the molecule about its axis. A strong anisotropy in the rotations of the allene molecule in the liquid state is evidenced: D∥/D⊥ ≃ 7. Furthermore, the rotational motion about the axis seems to digress from a diffusional motion more than the reorientation of the axis itself. Finally, the paper discusses those conditions in which the evaluation of the rotational diffusion constant from the Raman profile of a depolarized band is valid.
Systematic interpretation of Raman spectra of organic compounds. IV—nitrogen compounds
Authors: Visser T. , Van Der Maas J. H. 
Published: May 2005

AbstractThe Raman spectra of 79 nitrogen containing organic compounds have been recorded. The frequencies of amines, pyridines, cyanides, amides and nitro‐compounds are reported and correlations with the structure have been established by means of computer searching. The collected data have been incorporated into an interpretation system for C, H and O compounds, and difficulties in the interpretation of the data are reviewed. A further extension of the system is discussed.
Characterization of a few Raman lines of tryptophan
Authors: Hirakawa Akiko Y. , Nishimura Yoshifumi , Matsumoto Tadashi , Nakanishi Mamoru , Tsuboi Masamichi 
Published: May 2005

AbstractThe Raman spectrum of tryptophan has been observed in its neutral aqueous solution with 514.5, 488.0, 457.9, 363.8, and 257.3 nm excitation. The effects of N‐deuteration and 15N‐substitution of the indole ring on the Raman spectrum have been examined. A preliminary normal coordinate treatment of the indole ring has also been made. On the basis of these data, the vibrational mode and a possible origin of the Raman scattering intensity has been discussed for each of the 1623, 1555, 1436, 1344, 1016, 882, and 762 cm−1 Raman lines of tryptophan. The resonance enhanced line at 1623 cm−1 has been assigned to a vibration of the indole ring which is related to the b3g ring stretching vibration of naphthalene at 1636 cm−1. Its intensity is considered to come almost solely from the B̃ ← X̃ (La) electronic transition at 273 nm. It is therefore probable that the geometrical structure of the molecule is distorted along this vibrational coordinate on going from the ground (X̃) to the B̃ electronic excited state.