bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resonance CARS line shape analysis for a concentration series of a dye solution—a practicable method for the evaluation of third‐order susceptibilities
Authors: Pfeiffer M. , Lau A. , Werncke W. 
Published: May 2005

AbstractAn extension of the Fleming and Johnson procedure is presented for determining the molecular third‐order susceptibility parameters from three characteristic intensities within a CARS line profile (Imax, Imin, Imid). For CARS excitation close to a molecular one‐photon resonance, these three intensity values taken from one spectrum do not suffice for the determination of all relevant parameters. A simple procedure is given for overcoming this by combining the information from all the spectra within a concentration series, keeping the frequency of the CARS pump laser fixed. Uncertainty in the measured Imid value is overcome by applying a least‐squares fit of the spectra.Results obtained from resonance CARS measurements for Rhodamine 6G in ethanol are given.
Photodissociation of Br2 and the electronic Raman spectra of Br under argon ion laser light
Authors: Chang Hua , Chen Shu‐Hui 
Published: May 2005

AbstractThe electronic Raman transitions of atomic bromine between the 2P1/2 and 2P3/2 states have been observed at 3685 cm−1 using excitation with 4880 Å radiation from an argon ion laser. The intensities of the Raman bands in the Stokes and anti‐Stokes sides were studied by varying the laser power and the pressure of Br2. A mechanism or photodissociation process for the production of these atoms by the intense laser radiation is proposed. The crossing between the potential curves of the B3π and 1π states could be important in reducing the population of Br* in the 2P1/2 excited state, and therefore the intensity of the observed Raman band at the anti‐Stokes side was only about 1% of the intensity of the Stokes band. This would be a good method for studying photodissociation by means of Raman scattering from the dissociation products excited by the same laser radiation.
Raman spectra of solid complexes of trihalides of antimony and bismuth with trihalides of aluminium and gallium
Authors: Shamir Jacob , Rafaeloff Rafael 
Published: May 2005

AbstractEquimolar quantities of the trihalides of antimony and bismuth were fused with trihalides of aluminium and gallium and the solid products were studied by Raman spectroscopy. The spectra were interpreted on the basis of ionic structures prevailing in all these compounds, with the general formula [M15X2]+[M13X4]− (M15=Sb and Bi; M13=Al and Ga; X=CI and Br).
Vibrational dephasing of the ν3 mode of liquid allene
Authors: Zyung Taehyoung , Henderson Don O. , Her Jhy‐Yuan , Wilde Richard E. 
Published: May 2005

AbstractThe Raman spectrum of the ν3 mode of allene has been studied as a function of temperature throughout the temperature range of the liquid. Analysis of the spectral band shape shows that the vibrational dephasing is a fast‐modulation process. Evidence is presented for a vibrational‐rotational coupling involving the tumbling reorientation of the molecule. Dilution studies in GeH4 indicated significant resonant vibrational energy transfer.
Wavelength‐selective resonance Raman spectroscopy of a finite polyene: Solid‐state all‐trans‐β‐carotene
Authors: Mattioli T. A. , Haley L. V. , Koningstein J. A. 
Published: May 2005

AbstractTwo samples of solid all‐trans‐β‐carotene which differed in their degrees of crystallinity were studied using visible absorption and resonance Raman spectroscopy.The absorption spectrum of a commercial crystalline β‐carotene sample revealed two bands at 18 450 and 20 040 cm−1 which were not present in the absorption spectrum of a prepared amorphous sample. Instead, the spectrum of the amorphous material showed a band at 19 268 cm−1 which is in a position approximately half way between the 18 450 and 20 040 cm−1 bands. From these observations these two latter bands are assigned to the Davydov components of the crystalline β‐carotene.The resonance Raman spectrum of crystalline all‐trans‐β‐carotene revealed several frequencies for the backbone CC stretching mode, νcc, as the laser excitation wavelength was varied. This frequency was observed to vary between 1516 and 1525 cm−1. The amorphous carotene sample also exhibited a wavelength‐dependent Raman spectrum where νcc ranged from 1516 to 1522 cm−1 initially. On further exposure to laser radiation (30–60 min) at 514.5 nm, the range increased to an upper limit of 1525 cm−1, which was attributed to a photochemical product formed in both the crystalline and amorphous samples. The wavelength‐dependent νcc frequency of these carotene samples is interpreted as being due to resonance‐enhanced Raman bands of β‐carotene molecules with different effective double bond chain lengths originating from separate micro‐domains in the solid samples.
Time‐resolved resonance Raman study of photochromic 4‐(2′, 4′‐dinitrobenzyl)pyridine
Authors: Suzuki Shinichi , Isaka Hiroaki , Ito Shinichi , Hirukawa Shigeru , Matsubara Shinya , Takahashi Hiroaki 
Published: May 2005

AbstractTwo transient species involved in the photochromism of 4‐(2′, 4′‐dinitrobenzyl)pyridine have been detected by time‐resolved resonance Raman spectroscopy. Comparison of the spectra of the shorter and longer lived transient species with those of the anion and the N‐CH3 derivative, respectively, revealed that the shorter lived species is identical with the anion and the longer lived species is the NH quinoid tautomer. It is shown that the photochromism of this compound can be interpreted in terms of the involvement of the anion as the intermediate to the NH quinoid which is the photo‐activated transient blue substance usually observed.
Temperature‐dependent intensities of Raman bands of di‐n‐butylamine
Authors: De Carvalho L. A. E. Batista , Da Costa A. M. Amorim , Teixeira‐Dias J. J. C. , Barbosa Ester F. G. , Lampreia Isabel M. S. 
Published: May 2005

AbstractRaman spectra of di‐n‐butylamine show bands whose temperature‐dependent intensities clearly suggest the occurrence of different conformers in simultaneous equilibria. In particular, the Raman spectrum of the solid phase is compared with that of n‐nonane in order to identify the more stable conformation. In addition, intensity rations vs temperature for pairs of Raman bands in the CH stretching region exhibit a smooth variation between the liquid and solid.
Single crystal Raman spectra of potassium peroxodisulphate. Assignment of the vibrations of the S2O ion
Authors: Eysel Hans H. , Rösinger Gerold 
Published: May 2005

AbstractRaman spectra of oriented single crystals of potassium peroxodisulphate have been measured and revised x‐ray structural data are briefly presented. An assignment of the internal modes of the S2O82− ion was possible on the basis of intensities under different orientations.
Raman study of odd‐numbered C11C23n‐alkanes in their high‐temperature solid phases
Authors: Maissara M. , Devaure J. 
Published: May 2005

AbstractThe Raman spectra of solid odd‐numbered n‐alkanes were analysed in the frequency ranges corresponding to the LAM‐1 and the methyl rocking modes, in order to specify the nature and the quantity of the gauche forms occurring in the high‐temperature phases. The evolution of the LAM‐1 frequency under different pressure and temperature conditions is discussed in connection with the interlamellar distances. In the high‐temperature phases, the relative quantity and the nature of the gauche forms located at the ends and near the ends of the chains was estimated as functions of the chain length and of temperature.
Ultraviolet resonance Raman bands of guanosine and adenosine residues useful for the determination of nucleic acid conformation
Authors: Nishimura Yoshifumi , Tsuboi Masamichi , Kubasek William L. , Bajdor Krzysztof , Peticolas Warner L. 
Published: May 2005

AbstractThe ultraviolet resonance Raman (UVRR) bands of several guanine‐ and adenine‐containing mononucleotides were measured, and were compared with the classical and UVRR spectra of 9‐ethylguanine, which contains no furanose ring, in order to assess the effect of sugar conformation on the UVRR spectrum. For several guanine mononucleotides containing different furanose rings some differences were found in the Raman bands normally attributed to the purine vibrations. A similar effect exists with different adenosine mononucleotides. The fact that these vibrations are allowed in the rigorous resonance Raman effect indicates that they are coupled to the electronic transitions of the base. Differences which are seen between cyclic nucleotides, ribonucleotides and deoxyribonucleotides probably arise from differences in the conformation of the attached furanose rings. This provides a method for the identification of conformationally sensitive vibrations of purine rings in nucleic acids.
The Raman spectrum of potassium metavanadate
Authors: Park Y. S. , Shurvell H. F. 
Published: May 2005

AbstractRaman spectra of polycrystalline KVO3 have been recorded at various temperatures. Splittings have been observed for most fundamentals and the external mode region contains at least eight bands. The spectra are interpreted in terms of a group theoretical analysis based on the molecular symmetry and the known crystal structure. The frequency versus temperature plots for external modes of KVO3 indicate that a single crystal structure exists between 10 and 300 K.
15N isotopic effects on the Raman spectra of tribromoacetonitrile
Authors: Suero M. I. , McNeil L. E. , Márquez F. 
Published: May 2005

Abstract[15N]Tribromoacetonitrile was synthesized with an isotopic content of 99.4% and its Raman spectrum was recorded in the range 4000–50 cm−1; depolarization ratios were also measured. The isotopic shifts arising from 15N were determined and interpreted. The fundamental vibrations of Br3CCN and also some overtones, combinations and difference bands were assigned. The molecular structure of tribromoacetonitrile was studied employing GAUSSIAN‐ 82 ab initio theoretical calculations and the Teller‐Redlich isotopic product rule was applied by assuming the following geometrical parameters: CN = 1.163 Å, CC = 1.479Å, BrC = 1.950Å, <BrCBr = 110.33° and <CCBr = 108.58°.
Raman and infrared spectra of solid tin tetrabromide
Authors: Zeng W. Y. , Anderson A. 
Published: May 2005

AbstractRaman and infrared spectra of crystalline tin tetrabromide at temperatures between 20 K and the melting point, 304 K, are reported. No evidence of any solid‐state phase transition was found. Splittings of the four molecular modes are discussed in terms of crystal field effects and isotopic species. All twelve Raman and five of the nine infrared‐active lattice modes, predicted on the basis of a group theoretical analysis, have been observed. Since these peaks lie within a relatively narrow frequency range, and since the molecules are located on general sites in the unit cell, mixing between modes is likely to be considerable.
Infrared and resonance Raman spectroscopic studies of 1‐hydroxy‐9,10‐anthraquinone and its metal complexes
Authors: Dutta Prabir K. , Hutt Julie A. 
Published: May 2005

AbstractInfrared and resonance Raman spectra of 1‐hydroxy‐9, 10‐anthraquinone, its deuteriated and deprotonated forms and its metal chelates with CuII, NiII and CoII ions are presented. Vibrational assignments of the carbonyl, hydroxyl and the chelating unit of this chromophore are emphasized. It is found that the different metal ions force delocalization of the electrons on the chelate rings to different extents. The intensities of the Raman bands under resonance conditions suggest that the electronic band in the visible region is mainly of a charge‐transfer type from the metal to the ligand.
Spectra and structure of organophosphorus compounds. XXXI—Raman and infrared spectra and conformational stability of ethylphonothioic dichloride
Authors: Durig J. R. , Hizer T. J. 
Published: May 2005

AbstractThe Raman (3500–10 cm−1) and infrared (3500–50 cm−1) spectra of solid ethylphosphonothioic dichloride, CH3CH2P(S)Cl2, and its deuteriated analog, CD3CH2P(S)Cl2, have been recorded. Additionally, the Raman spectrum of the liquid has been recorded and qualitative depolarization values have been obtained. From the fact that several distinct Raman lines disappear on going from the liquid phase to the solid state, it is concluded that the molecule exists as a mixture of the trans and gauche conformers in the liquid phase with the gauche conformer being the more stable form and the only one present in the solid Gtate. A variable temperature study of the Raman spectrum of the liquid did not yield an enthalpy difference between the conformers. Relying mainly on group frequencies and relative intensities of the infrared and Raman bands, a complete vibrational assignment is proposed for the gauche conformer. This assignment is supported by a normal coordinate calculation, which was carried out utilizing a modified valence force field to obtain the frequencies of the normal modes and the potential energy distribution. All of these results are compared with corresponding quantities for several other organophosphines.
Reorientational relaxation in liquid 1,4‐dioxane as studied by Raman spectroscopy
Authors: Fatima M. , Marques R. M. Ferreira , Da Costa A. M. Amorim 
Published: May 2005

AbstractThe anisotropic Raman spectra of liquid 1,4‐dioxane have been recorded at several temperatures and at different concentrations of aqueous and carbon tetrachloride solutions. The rotational dynamics of the 1,4‐dioxane molecules under these conditions is discussed in terms of appropriate correlation functions, reorientational relaxation times and second‐order rotational spectral moments.
Vibrational spectra, phase transitions and conformers of 1,4‐dichlorobut‐2‐yne
Authors: Karlsson A. , Klaeboe P. , Nielsen C. J. 
Published: May 2005

AbstractThe Raman and IR spectra of 1,4‐dichlorobut‐2‐yne (DCB) as a liquid at various temperatures and as an amorphous and as metastable and stable crystalline solids at low temperatures have been recorded in the 4000–20 cm−1 range. Additional IR and Raman spectra of a high‐pressure crystalline phase were obtained at ca 17 kbar pressure.The broad unsymmetrical bands of DCB in the liquid and in the amorphous solid below 500 cm−1 suggest nearly free rotation in these phases at all of the temperatures investigated. Below ca 190 K a crystal containing the anti and above 190 K a crystal containing the gauche conformer of DCB were formed; the latter crystal is believed to be thermodynamically more stable at all temperatures. Only one high‐pressure crystal with molecules in the anti conformation was formed at room temperature. A phase transition reported at 232 K in the liquid, involving a conversion to an anti conformer, was not detected.Complete vibrational assignments for both anti and gauche conformers are presented, supported by force constant calculations.
Conformational features of lipids and proteins in myelin membranes using Raman and infrared spectroscopy
Authors: Carmona P. , Ramos J. M. , De Cózar M. , Monreal J. 
Published: May 2005

AbstractMyelin membrane and its proteolipid protein (PLP) have been examined by infrared and Raman spectroscopy to provide information about the secondary structure of proteins and conformation of lipid chains. Splitting of the amide I modes in the vibrational spectra and locations of amide A, I, II, III and V bands indicate that the polypeptide arrangement in both membrane systems is mainly helical. The β‐form is also present, its amount being higher in PLP. Raman spectra in the CC and CH stretching regions show significant differences concerning intra‐ and inter‐chain lipid order, which is greater in PLP.
Theory of Fermi resonances in Raman and infrared spectra
Authors: Monecke J. 
Published: May 2005

AbstractFermi resonances are analysed in the literature either by degenerate first‐order perturbation theory or by the coupled oscillator model of Schwartz and Wang. Here the perturbation treatment is generalized, taking into account the coupling not only between a fundamental and an overtone, but also with other eigenstates, required by a proper treatment of the Bose character of vibrations. The resulting expressions for the frequency shifts differ from those of both other models. Numerical differences from the first‐order perturbation treatment are small in most cases. However, the results can be used to relate the empirical interaction constant of the coupled oscillator model to an actual anharmonicity constant.
Raman and infrared spectra of transition metal halide hexahydrates
Authors: Agulló‐Rueda F. , Calleja J. M. , Martini M. , Spinolo G. , Cariati F. 
Published: May 2005

AbstractThe Raman and infrared spectra of NiCl2·6H2O, NiCl2·6D2O, CoCl2·6H2O, CoCl2·6D2O and CoBr2·6H2O single crystals have been measured in the range 3600–30 cm−1 (Raman) and 3800–400 cm−1 (IR). The water internal modes have been best assigned for NiCl2·6H2O, including Fermi resonance effects. The corresponding Raman intensities have been interpreted in terms of the free molecule Raman tensors. Among the lattice vibrations, the metal halide and metal‐water stretchings, and also the librations of the MX2·4H2O octahedra, have been identified and assigned.
Assignment of the forbidden level of the Fermi doublet in the Raman spectrum of CH2Br2
Authors: Bertrán José Fernández , La Serna Torres Boris , Félix Denis Fernández , Lokshin Boris 
Published: May 2005

AbstractThe modified Winther method was used to analyse different assignments of the forbidden level νf in Fermi resonance with the symmetric CH2 stretch ν1 in CH2Br2. Of a set of five differnt combination levels, three were rejected and two plausible assignments are discussed.
Raman and infrared spectra of the all‐trans, 7‐cis, 9‐cis, 13‐cisand 15‐cisisomers of β‐carotene: Key bands distinguishing stretched or terminal‐bent configurations form central‐bent configurations
Authors: Koyama Yasushi , Takatsuka Ichiro , Nakata Munetaka , Tasumi Mitsuo 
Published: May 2005

AbstractRaman and infrared spectra in the region of 1800‐150 cm−1were recorded for a set ofcis‐transisomers of d̃‐carotene, i.e. the all‐trans, 7‐cis, 9‐cis, 13‐cisand 15‐cisisomers. Spectral comparison revealed Raman and infrared key bands which (1) distinguish stretched or terminal‐bent configurations (all‐trans, 7‐cisand 9‐cis) from central‐bent configurations (13‐cisand 15‐cis), and (2) distinguish unmethylated 7‐cisand 15‐cisconfiguratios. Keybands (1) include Raman bands at 1160 and 1140 cm−1and infrared bands at 825 and 775 cm−1(the intensity varies with the position of thecis‐bend) Key bands (2) include Raman bands at 1274 and 962 cm−1and an infrared band at 741 cm−1(characteristic of the 7‐cisconfiguration), and also a Raman band at 1247 cm−1and an infrared band at 775 cm−1(characteristic of the 15‐cisconfiguration). The normal modes for the key bands were determined by a set of normal coordinate calculations for the isomeric configurations of a simplified model of d̃‐carotene. The key bands were mainly related to the CH in‐plane bendings, coupled with the CC or CC stretching, or to the CH out‐of‐plane wagging vibrations, some of which coupled with the CC torsion.
Raman and far‐infrared spectra of solid carbon tetrabromide
Authors: Hird K. M. , Binbrek O. S. , Anderson A. , Torrie B. H. 
Published: May 2005

AbstractRaman and far‐infrared spectra of solid CBr4 at temperatures between 20 K and the melting point, 365 K, have been recorded. Low‐temperature results are compared with earlier data and with the predictions of a group theoretical analysis based on the known crystal structure. Isotopic and crystal field effects are distinguished. The number of Raman peaks, especially in the lattice and v3 regions, is compatible with a large unit cell. Certain features are interpreted with the help of recent spectra and calculations on solid SnBr4, Which has a similar unit cell.
Raman and far‐infrared study of the lattice vibrations of methanol
Authors: Anderson A. , Andrews B. , Meiering E. M. , Torrie B. H. 
Published: May 2005

AbstractRaman and far‐infrared spectra of the lattice vibrations of solid methanol in the ordered α‐phase at 20 K are presented and discussed in terms of the available crystallographic data. Spectra of the deuterated species, CH3OD and CD3OD, have also been recorded to facilitate the assignment of observed peaks. The spectroscopic data are compatible with a centrosymmetric monoclinic unit cell containing four molecules on general sites.
Raman study of a 4‐nitropyridine N‐oxide single crystal. 1—Lattice vibrations
Authors: Joyeux Marc , Jouan Michel , Dao Nguyen Quy 
Published: May 2005

AbstractHigh‐quality single crystals of 4‐nitropyridine Noxide (NPO) and 4‐nitropyridine‐d4 N‐oxide (NPO‐d4) of adequate size were prepared by slow recrystallization from an acetone solution. Low‐frequency polarized Raman spectra were recorded in the range 6–200 cm−1. The external vibrations were assigned using group theory and assuming that the libration frequencies are inversely proportional to the square root of the moments of inertia; in the spectra of NPO, the Ag‐B2g components appear at 37–43 cm−1 for Ry and at 51–61 cm−1 for both Tx and Tz, because pseudo‐degeneracy occurs; the B1g ‐B3g components appear at 51–35 cm−1 (Rx), 89–110 cm−1 (Rz) and 152–163 cm−1 (Ty). Two internal vibrations which appear below 200 cm−1 are also assigned: the NO2 twisting at 79 cm−1 and an out‐of plane bending vibration of the N‐oxide and NO2 groups at 121–145 cm−1. As expected, the NPO‐d4 spectra show little difference from that of NPO. The influence of the intermolecular bonds on the frequencies, splittings, widths and intensities of the lines is discussed.
Raman spectroscopic study of Bacillus subtilis extracellular levansucrase: Effect of iron (III) ions on the protein conformation
Authors: Gróf Pál , Aslanian Dimitrina , Chambert Regis 
Published: May 2005

AbstractVibrational Raman spectroscopy has been used to study the conformation of the extracellular enzyme levansucrase. Secondary structure analysis by the method of Williams shows 51% β‐sheets, 18% total α‐helical structure (from 7 to 16%) and modifies the environment of the Trp and Phe residues and also more of the CC, CN, CS and CH3 groups.
Spectres de Vibration de l'Acide Furanne 2,3‐Dicarboxylique et de ses Sels de Potassium en Solution Aqueuse
Authors: Cassanas G. , Fabrègue E. , Bardet L. 
Published: May 2005

AbstractLes spectres Raman et infrarouge de l'acide furanne 2,3‐dicarboxylique et de ses sels de potassium en solution aqueuse ont été étudiés de 100 à 4000 cm−1. Une attribution des fréquences de vibration est proposée. L'état de polarisation des raies Raman montre que le noyau furannique est plan. Les groupements carboxylates de l'ion neutre sont orthogonaux. La liaison H‐intramoléculaire présente dans l'acide et le sel acide à l'état cristallin est assez forte pour subsister en solution aqueuse, les pseudo‐cycles ainsi formés sont contenus dans le plan furannique.