bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectroscopic study of single crystal of β‐naphthol low‐frequency vibrations oriented gas model and lattice dynamics
Authors: Szostak M. M. , Sanquer M. , Meinnel J. 
Published: May 2005

AbstractThe polarized Raman and FIR spectra of a β‐naphthol single crystal have been recorded in the 10–200 cm−1 region. The spectra have been interpreted on the basis of an oriented gas model associated with lattice dynamic calculations assuming a ‘6‐exp.’ potential between non‐bonded atoms and a simple harmonic force constant between oxygen atoms linked by hydrogen bonds.
Etude Vibrationnelle de trans‐Dicyano‐4,5 Cyclohèxenes: 2—Spectres Raman et IR de Tertiobutyl‐3 Dicyano‐4,5 Cyclohexènes D0, D3 (‐3,6,6) et D5 (‐3,4,5,6,6) à Conformations Bloquées
Authors: Davidovics G. , Gedoux B. , Aycard J. P. , Pourcin J. 
Published: May 2005

AbstractRaman and infrared spectroscopic investigation of 3r, 4t, 5c and 3r, 4c, 5t diastereoisomers of d0, ‐3,6,6 d3 and ‐3,4,5,6,6 d5, ‐3 tertiobutyl, ‐4,5 dicyano cyclohexenes in the solid and dissolved states is performed. From conformational and Teller Redlich product rule considerations, the whole fundamental vibrations are assigned. Specific vibrations relative to (XCCN)2 (X = H or D) groups with diequatorial or diaxial nitriles are outlined.
The infrared and Raman spectra of isoelectronic potassium imidosulphonate, K2NH(SO3)2 and potassium methylenedisulphonate, K2 CH2 (SO3)2
Authors: Hall John R. , Johnson Robert A. 
Published: May 2005

AbstractThe polycrystalline IR and Raman spectra (4000–50 cm−1) of isoelectronic K2NH(SO3)2 and K2CH2(SO3)2 have been recorded at 77 K. These salts are isomorphous at ambient temperature (space group C2/c (C2h6)) but K2NH(SO3)2 undergoes a phase change on cooling to 77 K. Possible low‐temperature structures for the latter are proposed and their predicted spectra are compared with the observed spectra. The phase change appears to be limited to an ordering of hydrogen atoms to give a structure with space symmetry P1(C11) with Z = 4. To assist with the band assignment, spectra of the 2H analogues of both salts and the 15N analogue of K2NH(SO3)2 have been recorded. Aqueous solution spectra, including qualitative Raman polarization data have also been obtained for the highly soluble salts (NH4)2NH(SO3)2 and Na2CH2(SO3)2·2.5H2O and their 2H analogues. For NH(SO3)22−, the skeletal modes are assigned frequencies of 858 cm−1 (νasymNS), 842 cm−1 (νsymNS) and c. 180 cm−1 (δNS2). The corresponding CH2(SO3)22− frequencies are 800 cm−1 (νasymCS), 776 cm−1 (νsymCS) and c. 180 cm−1 (δCS2). The SO3 groups show their characteristic frequencies which are very similar for both species.
Analyse Vibrationnelle et Structurale en Série Aliphatique Saturée 3—Spectres de Vibration de l'Acide Méthylmalonique et de ses Sels Alcalins en Solution Aqueuse
Authors: Delarbre Jean Louis , Bardet Lucette , Maury Luc 
Published: May 2005

AbstractRaman and infrared spectra of méthylmalonic acid CH3CH (COOH)2, CH3CD(COOD)2 and its alkaline salts CH3CH(COOH)(COOD)2, CH3CD(COOD)(COOK) and CH3CH(COOK)2, CH3CD(COOK)2 in aqueous solution have been investigated from 3500 to 200 cm−1; an assignment of the fundamental vibrations is proposed. The analysis of the polarization ratio lead us to conclude that neutral salt belongs to point group Cs. The acid salt and the acid itself belong to point group C1 and cannot exhibit intramolecular hydrogen bonding.
Raman spectra of liquid cyclopropyl cyanide
Authors: Maillols Jacques , Tabacik Vlado , Sportouch Serge 
Published: May 2005

AbstractThe Raman spectra of liquid cyclopropyl cyanide (range 50–4000 cm−1) are reported and found considerably different from those published by Daly and Wiberley.1 A new assignment is given based on the study of both Raman and IR spectra (liquid and gas) and on a model NC treatment permitting to correlate them with the spectra of cyclopropane and acetonitrile.
Infrared excited resonance Raman spectra of lobster shell pigments in situ
Authors: Nelson W. H. , Carey P. R. 
Published: May 2005

AbstractResonance Raman spectra, obtained with 676.4 and 752.5 nm excitation, are reported for the carotenoid molecule astaxanthin in situ in the shell of a lobster. The spectra show unusual frequency shifts and absolute intensity behaviour in the case of 676.4 and 752.5 nm excitation, respectively, and support the hypothesis that the shell contains astaxanthin bearing pigments which have not yet been isolated and characterized.
Raman dispersion spectroscopy (RADIS): 1—Phenomenology
Authors: Mortensen O. Sonnich 
Published: May 2005

AbstractRADIS is a novel spectroscopic technique for the investigation of vibronic states. It differs from the common alternative absorption spectroscopy in two significant ways: (a) there is a distinct RADIS spectrum for every band in the Raman spectrum versus just one absorption spectrum; (b) the observables in RADIS are determined by a tensor quantity, and so polarization measurements are useful and significant also for isotropic systems like molecules in solution. In this paper the phenomenology of RADIS is discussed, with special emphasis on molecules in solution. There are three different RADIS spectra for isotropic systems, namely (i) an intensity spectrum, (ii) a linear polarization spectrum and (iii) a circular polarization spectrum. From these one may obtain three different intensity spectra, one for each tensor invariant. A parametrization of these spectra is given. It is shown that the spectra have the form of a simple superposition of Lorentzians, with resonance frequencies determined by the energies of the adiabatic molecular states. Inhomogeneous broadening is treated by means of simple spectral convolution. It is shown that when the inhomogeneous lineshape is Lorentzian, the RADIS intensity retains its Lorentzian form, while a Gaussian lineshape leads to RADIS spectra described by the complex error function.
Raman scattering in optical fibers
Authors: Lan Guey‐Liou , Banerjee P. K. , Mitra S. S. 
Published: May 2005

AbstractIn this paper we review the light scattering spectra of optical fibers and present new data on Raman spectra of optical fibers. The results include Raman spectra of fused silica fibers and effects of dopants and irradiation‐Large scattering volumes available in optical fibers afford one to detect low dopant concentrations and relatively weak second order spectra. Low frequency Raman spectra of optical fibers shows the expected non‐Debye type anomaly.
Temperature and pressure Raman study of molecular motions in liquid CH2Cl2
Authors: Hacura Andrzej , Żerda Tadeusz W. , Kaczmarski Marceli 
Published: May 2005

AbstractThe Raman line shapes of three symmetric modes ν1, ν3 and ν4 have been measured in liquid dichloromethane as a function of pressure from 1 bar to 3 kbar and of temperature from 183 to 363 K. The reorientation relaxation times are found to increase with higher pressures and to decrease with increasing temperatures. The isotropic half‐width of the ν4 band behaves untypically, varying only insignificantly throughout the temperature and pressure range studied. The differences in frequency between the polarized and depolarized bands are also determined. The dipolar coupling mechanism is applied to interpret the effects observed.
On the role of exciton‐phonon interaction in the interpretation of the relative intensities in the Raman lattice spectrum of crystalline p‐chloroaniline
Authors: Szostak M. M. , Sanquer M. , Girard A. 
Published: May 2005

AbstractThe relative intensities of bands in a polarized Raman Lattice spectrum of p‐chloroaniline are interpreted in terms of the oriented gas model. Among different reasons for deviations from this model the vibronic intensity enhancement of B1g and B3g lattice bands has been found to be the most important one.
Raman spectroscopic study of MoO3/γ‐Al2O3 and CoO(or NiO)‐MoO3/γ‐Al2O3 oxide catalysts prepared by different methods
Authors: Agudo A. López , Gil F. J. , Calleja J. M. , Fernández V. 
Published: May 2005

AbstractRaman spectroscopy has been used to characterize various MoO3/γ‐Al2O3 and CoO (or NiO)‐MoO3/γ‐Al2O3 catalysts containing 12 wt% MoO3 and 3 wt% CoO (or NiO) prepared by different methods. No significant differences between samples prepared by the wet impregnation and the pore volume method could be observed in molybdena‐supported catalysts; in these samples the majority of Mo is present as isolated distorted MoO42− tetrahedra due probably to a low coverage of the alumina surface (SBET=240 m2 g−1). Addition of NiO to the molybdena‐supported catalysts seems to cause only a slight increase in the distortion and interaction between MoO42− species. In contrast, CoO addition to the molybdena‐supported catalysts changes considerably the spectra features, suggesting that the Mo species are highly distorted, presumably in different surroundings on the alumina surface, due to the strong interaction of Co with Mo species. However, simultaneous impregnation of both MoO3 and CoO or NiO results in a more regular arrangement of Mo species and an increase in formation of polymeric Mo species, particularly with Co‐containing catalyst, where a relative higher degree of polymeric aggregation may occur.
Spectra and structure of gallium compounds: 8—Vibrational studies of trimethylgallane‐dimethylether and trimethylgallane‐dimethylether‐d6
Authors: Odom J. D. , Wasacz F. M. , Sullivan J. F. , Durig J. R. 
Published: May 2005

AbstractThe infrared (4000–80 cm−1) and Raman (3500–10 cm−1) spectra of (CH3)3GaO(CH3)2 and (CH3)3GaO(CD3)2 have been recorded for the solid state at 77 K. The Raman spectra of the liquids have also been recorded and depolarization values measured. The spectra have been interpreted in detail on the basis of Cs molecular symmetry. The valence force field model has been utilized in calculating the frequencies and potential energy distribution for the heavy atom skeleton. Considerable coupling has been observed among the OC2 bending motions and the GaC3 bending modes. The GaO stretch could not be assigned to a particular low frequency band, but this motion contributed significantly to four different bands ranging in frequency from 279 to 148 cm−1. The calculated force constants for the adducts are compared to those previously reported for the Lewis base moiety and the differences are shown to be consistent with structural changes expected upon adduct formation.
Kinetics of hydrogen‐deuterium exchange and kinetic isotope effects in inosine‐5′‐ monophosphate and inosine‐3′5′‐ monophosphate determined by laser Raman spectroscopy
Authors: Ferreira Susan A. , Thomas G. J. 
Published: May 2005

AbstractThe rates (kH) of deuterium exchange of 8‐CH groups, as well as the rates (kD) of protium exchange of 8‐CD groups in 5′‐IMP and cIMP, were measured by laser Raman spectrophotometry over the temperature range 30–80°C. The kH, or ‘forward’ rates, were determined from exchange in D2O solutions, while the kD, or ‘reverse’ rates, were determined from exchange in H2O solutions of the nucleotides. The hypoxanthine nucleotides were found to exchange with rates intermediate between those of corresponding adenine and guanine nucleotides, reported previously. The values obtained for the rate constants as a function of temperature (k=A exp (‐Ea/RT)) yield the following Arrhenius activation energies and frequency factors. For 5′‐IMP: EaH=25.5±0.6 kcal mol−1, AH=2.61×1015h−1; EaD=24.9±0.6 kcal mol−1, AD=4.32×1014h−1. For cIMP: EaH=22.2±0.6 kcal mol−1, AH=2.52×1013h−1; EaD=21.4±0.6 kcal mol−1, AD=3.93×1012h−1. The lower activation energy for cIMP accounts for its more rapid exchange vis‐à‐vis 5′‐IMP, confirming the trend observed also for adenine and guanine nucleotides. Moreover, as in the cases of adenine and guanine isomers, the differential exchange between cyclic and 5′‐nucleotides of hypoxanthine is large at lower temperatures and small at higher temperatures. These results confirm that exchange at 8‐C is influenced by the ribosyl phosphate group. The present data also provide evidence of small kinetic isotope effects in the 8‐C exchange reactions. For 5′‐IMP, kH/kD≈2.5, and for cIMP, kH/kD≈1.7. The isotope effects of 5′‐IMP and cIMP are close to the values observed for guanine nucleotides. Finally, Raman vibrational spectra of four isotopic modifications of the hypoxanthine nucleotides are compared to provide specific assignments of the Raman bands to vibrations of the purine skeleton and its exocyclic substituents.
Raman studies of reorientational relaxation of cyclohexane in the liquid state
Authors: Bien T. , Döge G. 
Published: May 2005

AbstractReorientational correlation functions have been obtained from the analysis of the totally symmetric vibrations ν4, ν5 and ν2 of liquid cyclohexane. For the interpretation of the data, the Kubo line shape theory was assumed to be valid. The most reliable results were obtained from the ν4 vibration and indicated that reorientational relaxation occurs close to the Debye limit of rotational diffusion. The data are compared with NMR results given in the literature. The effects of rotational‐vibrational coupling are discussed.
Raman spectral investigation of the cadmium thiocyanate complexes in solutions and solid
Authors: Antié‐Jovanovié A. , Jeremié M. , Long D. A. 
Published: May 2005

AbstractRaman intensity measurements have been made of cadmium thiocyanate aqueous solutions containing various ratios of total cadmium to total thioeyanate. Both Job and mole‐ratio methods indicated existence of a distinct complex species with a cadmium to thiocyanate ratio from 1 to 4. All average ligand number values obtained from three different series of experiments lie on the same curve, meaning that only mononuclear species are formed. Four overall stability constants have been calculated. The spectra are consistent with mononuclear complexes in solution, some having SCN− attached to the metal through the sulphur, others through the nitrogen. A band observed at 2132 cm−1 was assigned to the Cd(SCN)+ complex while bands observed at 2102 and 784 cm−1 were attributed to higher members of the stepwise Cd(NCS)n2−n series. The spectra of solid Cd(SCN)2 were in accord with a bridged thiocyanate structure. Assignments were supported by x‐ray structural studies.
Characteristic Raman bands for Azo and hydrazone structures
Authors: Jacques P. 
Published: May 2005

AbstractRaman spectra of two hydroxy azoic model compounds: 3,5‐dimethoxy‐4‐hydroxyazobenzene and 2,6‐dimethoxy‐4‐hydroxyazobenzene are compared. These compounds exist as the pure azo and pure hydrazone forms respectively, thus allowing the assignment of numerous Raman Bands characteristic of each tautomer. The usefulness of Raman spectroscopy for investigating azo‐hydrazone tautomerism is illustrated by a study of 2‐hydroxy‐5‐methyl‐azobenzene which is clearly proved to exist entirely in the azo form.
Vibrational analysis of peptides, polypeptides and proteins. XII—fermi resonance analysis of the unperturbed ND stretching fundamental in polypeptides
Authors: Krimm S. , Dwivedi Anil M. 
Published: May 2005

AbstractWe have obtained the spectrum of β‐poly(L‐alanine‐ND), and find three bands in the ND stretching region. By comparison with Fermi resonance analyses of deuterated derivatives of polyglycine I as well as with α‐poly(L‐alanine‐ND), we conclude that a three‐level Fermi resonance is involved in the β polypeptide, and that the unperturbed ND stretch fundamental occurs near 2428 cm−1.
Raman studies of L‐histidine and related compounds in aqueous solutions
Authors: Tasumi Mitsuo , Harada Issei , Takamatsu Tadahisa , Takahashi Seizo 
Published: May 2005

AbstractThe Raman spectra of L‐histidine, L‐histidine‐ 13C (labelled at C2 of the imidazole ring) and related compounds, namely, imidazole, 4‐methylimidazole, N‐acetyl‐L‐histidine methylamide, were observed in H2O and D2O solutions at various pH and pD values. A strong Raman band at around 1410 cm−1 was found for these compounds in acidic D2O solutions, and it was assigned to a mode characteristic of the N‐deuterated imidazolium ring (Im+) in which the N1C2N3 symmetric stretching and ND bending vibrations are mixed. It is concluded that this band would be useful as a probe for studying the ionization states of histidine residues in proteins.
Alkene‐halogen complexes studied by matrix isolation vibrational spectroscopy
Authors: Holroyd S. , Barnes A. J. , Suzuki S. , Orville‐Thomas W. J. 
Published: May 2005

AbstractVibrational spectra of mixtures of chlorine, bromine or iodine with ethene or 2,3‐dimethylbut‐2‐ene (tetramethyl‐ethene) in low‐temperature argon or nitrogen matrices are reported. The shifts observed for the halogen and CC stretching modes of the 1:1 alkene‐halogen complexes are related to the structure of the complexes.
A polarized infrared and Raman spectroscopic study of the electrooptic crystal m‐nitroaniline. 2—lattice vibrations
Authors: Szostak M. M. 
Published: May 2005

AbstractThe polarized Raman spectra of meta‐nitroaniline single crystals in the 10–150 cm−1 region as well as the far‐infrared spectra of the (010) platelets in the 20–200 cm−1 region have been measured and assignments of all expected bands have been proposed on the basis of the observed polarizations. To estimate the influence of the electrooptical properties of the crystal on the lattice spectra, the relative intensities of librational bands have been calculated from the oriented gas model, and observed discrepancies have been discussed. Comparisons with the spectra of the isomeric crystal p‐nitroaniline and of a similar non‐centrosymmetric crystal m‐chloronitrobenzene have been made.
The effect of inhomogeneous broadening on the absorption spectra and excitation profiles of resonance Raman and coherent anti‐stokes Raman scattering of polyatomic molecules
Authors: Lukashin A. V. , Frank‐Kamenetskii M. D. 
Published: May 2005

AbstractA uniform treatment of the effect of inhomogeneous broadening on the absorption spectra and the excitation profiles of resonance Raman scattering and coherent anti‐Stokes Raman scattering is presented. For the case of Gaussian distribution of molecular energy values general expressions are obtained which are valid for arbitrary values of homogeneous and inhomogeneous broadening parameters. Just as for resonance Raman scattering excitation profiles, the coherent anti‐Stokes Raman scattering excitation profiles are quite sensitive to the mechanism of vibronic line broadening. The simple relation between resonance Raman scattering and coherent anti‐Stokes Raman scattering excitation profiles is shown to be valid only if the effect of inhomogeneous broadening is negligible. We suggest that this fact should be used for experimental estimation of the impact of inhomogeneous broadening. We discuss the possibility of using absorption data as well as resonance Raman scattering and coherent anti‐Stokes Raman scattering excitation profiles for testing the adequacy of the original model of vibronic theory.
Magnetic resonance‐Raman optical activity of ferrocytochrome c theory and experiment
Authors: Barron L. D. , Meehan C. , Vrbancich J. 
Published: May 2005

AbstractThe theory of magnetic resonance Raman optical activity in metal porphyrins is developed. Irreducible tensor methods are used to calculate the transition polarizabilities (involving both symmetric and antisymmetric contributions) which are formulated in terms of a vibronic development of the Raman transition tensors. The circular intensity difference for the vibrations of symmetry species A1, A2, B1 and B2 is explicitly evaluated for excitation within the 0–0 and 0–1 visible absorption bands. Polarized, depolarized and unpolarized magnetic resonance Raman optical activity spectra of ferrocytochrome c within the 0–0 and 0–1 bands are presented. Good qualitative agreement is found between theory and experiment.
A Raman spectroscopic temperature study of NH3+ torsional motion as related to hydrogen bonding in the L‐alanine crystal
Authors: Forss S. 
Published: May 2005

AbstractA Raman study of the NH3+ torsional mode in the amino acid L‐alanine has been performed. The temperature dependence of this mode has been followed in the temperature region 110–350 K. The activation energy for NH3+ reorientation obtained from a linewidth vs temperature investigation, Ea = 3100±400 cm−1, is in excellent agreement with corresponding NMR results, thus demonstrating that Raman spectroscopy can serve as a complementary method to NMR in obtaining torsional barrier heights. Based on an X‐ray investigation, crystal and hydrogen bond parameters have been calculated as a function of temperature. The increase of the NH3+ torsional barrier on going to lower temperatures is essentially attributed to the shortening of one specific hydrogen bond. The detection of the NH3+ torsional hot transition is important for the determination of the shape of the lower portion of the NH3+ torsional potential. The sixfold term V6 of the potential used, three‐plus sixfold, is thus very sensitive to the frequency difference between the NH3+ torsional fundamental and hot band. The optimum frequency fit gives, however, too large a value for the barrier height V3. The reason for this is interpreted as arising from the severe distortion of the hydrogen bonds at large torsional angles. The results presented here support recent findings that a revision of the dynamic picture of the hydrogen bonds in L‐alanine crystal, as reported in two earlier papers, is needed.
Laser Raman and infrared spectra of di‐potassium tartrate hemi‐hydrate
Authors: Srivastava G. P. , Mohan S. , Jain Y. S. 
Published: May 2005

AbstractAn analysis of the Raman and infrared spectra of di‐potassium tartrate hemi‐hydrate (DKT), K2C4H4O6·½H2O, is reported. It has been inferred that the C4H4O ion and H2O molecule in a DKT crystal occupy points of C1 site symmetry. Various units of C4H4O ion/(H2O molecule) located at crystallographically distinguishable positions in this crystal do not appear to be different in their structure or the force fields governing their vibrational dynamics.
Raman spectrum of NH4ReO4 at high pressure
Authors: Klug D. D. , Sim P. G. , Brown R. J. C. 
Published: May 2005

AbstractThe pressure dependences at room temperature of the translational lattice modes and of the ν2 and ν4 internal bending modes of the ReO ion in solid NH4ReO4 are reported. There is no evidence of any phase transition up to a pressure of 15 kilobar. The pressure coefficients of the translational modes are 2.0 cm−1 GPa−1 and 3.0 cm−1 GPa−1 for the Bg and Eg modes respectively. The pressure coefficients of the bending modes are 1.0 cm−1 GPa−1 and 5.4 cm−1 GPa−1 for the Bg and Ag components of ν2, and 4.1 cm−1 for the overlapped Bg and Eg components of ν4.The symmetry assignments of the low frequency lines in the spectrum were checked by means of polarized Raman spectra of a single crystal. The previous assignments are correct.
Activité Raman et Infrarouge des Cristaux Piezo Electriques BeSO4·4 H2O et BeSO4·4 D2O. 1–Vibrations Principales et Structure
Authors: Pigenet Claude 
Published: May 2005

AbstractLes cristaux piezo‐élecriques BeSO4·4H2O ont été étudiés par diffusion Raman (4000 à 4 cm1) et spectroscopie infrarouge (4000 à 30 cm−1). Les modes normaux (sans les modes longitudinaux) ont été observés et attribués. Les modes relatifs aux groupements tétraédriques Be(H2O)4, ce qui est démontré par la substitution du deutérium, nous ont permis de calculer des constantes de force F,(BeOH) = 3.21 modyn A−1 et F α/r2(H2O−BeOH2) = 0.285 modyn A−1. Les modes internes des molécules d'eau et les modes de basse fréquence ont été reliés à la structure qui comporte deux liaisons hydrogène.