bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laser Raman scattering and preresonance in Co(III)‐ATP complexes
Authors: Yu Nai‐Teng , Lanir A. , Werber M. M. 
Published: May 2005

AbstractInteractions of cobalt(III) ion with adenosine‐5′‐triphosphate in the presence of 1,10‐phenanthroline and superoxide were studied by laser Raman spectroscopy. Striking intensity enhancement of two adenine ring vibrations at 734 and 1430 cm−1was observed upon formation of the complex Co(III)‐(phen)‐ATP‐O2−. The effect could be abolished by addition of cyanide ion to replace the superoxide ion. The spectral features were interpreted as indicating a direct binding of Co(III) to the C6‐NH2group of adenine. The interaction between Co(III) and 1,10‐phenanthroline was manifested in the frequency and intensity changes near 436 and 1064 cm−1. Raman intensities at 734, 1312, 1055 and 1430 cm−1were measured as a function of laser exciting wavelength. The gradual changes in Raman excitation profiles of ATP lines from 647.1 nm to 457.9 nm indicated the preresonance effect with a charge transfer transition between adenine and Co(III), which may lie between 300 and 400 nm as evidenced by the more dramatic enhancement of these lines with 406.7 nm excitation.
Spectra and structure of gallium compounds: V—Infrared and Raman spectra of gaseous, liquid and solid trimethylgallium
Authors: Durig J. R. , Chatterjee K. K. 
Published: May 2005

AbstractThe Raman spectra (50–3500 cm−1) have been recorded for gaseous, liquid and solid trimethylgallium. The infrared spectra (40–4000 cm−1) have also been recorded for trimethylgallium in the vapor and crystalline states. A complete vibrational assignment is proposed and the out‐of‐plane, GaC3 deformation is assigned to an infrared band observed at 150 cm−1 in the spectrum of the vapor. The vibrational spectrum of the solid is very simple which indicates that the molecule remains monomeric. Only one lattice mode was observed in the far infrared spectrum and none in the Raman spectrum. The spectrum of the solid can best be interpreted on the basis of C3 site symmetry with either one or two molecules per unit cell. Normal coordinate calculations for the skeletal modes have been carried out utilizing a four atom approximation.
Preresonance Raman spectroscopy of the rhodium hexabromide anion
Authors: Spoonhower John P. 
Published: May 2005

AbstractRaman spectroscopy was used in structural studies of solution‐phase RhBr63− anions. The observed spectra are consistent with an octahedral ground‐state structure. Polarization measurements of the ν1(A1g) and ν2(Eg) vibrational modes support the contention of cubic symmetry. The degree of polarization of these lines is independent of laser wavelength, not unlike observations of other d6 hexahalide complexes. No resonance enhancement is observed with either T1g or T2g electronic transitions in the visible spectral region. Rather it is believed that the Raman transitions obtain intensity by way of virtual excitation of the allowed T1u electronic transition in the near‐ultraviolet portion of the spectrum.
Low frequency Raman spectra of C2H5NH+Br− as a function of pressure up to 10 kilobars
Authors: Ratcliffe C. I. , Sherman W. F. , Wilkinson G. R. 
Published: May 2005

AbstractRaman spectra of a single crystal of C2H5NH3Br have been obtained at several pressures up to 10 kbar, to observe, in particular, the behaviour of the two torsional modes. Several bands show dramatic pressure shifts. The CH3 torsion shows the largest shift of all (1.918±0.039 cm−1 kbar−1), in striking contrast to the NH3+ torsion which does not shift with pressure. Threefold barriers to rotation, and their pressure dependence, have been calculated from the torsional frequencies. An explanation of the observed behaviour has been sought in terms of hard and soft regions in the lattice structure.
Raman and IR spectra of tetrachloro phosphonium salts of some tetrachlorate (MCI4−) anions
Authors: Shamir Jacob , van der Veken Benjamin J. , Herman Medard A. , Rafaeloff Rafael 
Published: May 2005

AbstractComplete Raman and IR spectra were recorded for the tetrachloro phosphonium salts of tetrachloro‐aluminate, gallate, indate and ferrate. The spectra are interpreted on the basis of these complexes being of ionic structure of the general formula: PCL4+MCI4−. All the accordingly expected fundamentals have been observed and assigned.
Polarized Raman and infrared spectra of a multilayer KY (MoO4)2 crystal
Authors: Hanuza J. , Łabuda L. 
Published: May 2005

AbstractPolarized Raman and IR spectra of a single KY(MoO4)2 crystal were measured in the 10–4000 cm−1 region and discussed in relation to the molecular and crystal structures. Spectroscopic data enabled us to reveal additional intermolecular interactions due to pair coupling of the molybdate tetrahedra verifying information on the crystal layer structure of double molybdates from the KLn(MoO4)2 family.
Etude par Spectrométrie Raman du Matériau Obtenu par Insertion de l'acide Sulfurique dans le Graphite
Authors: Iskander Bachir , Vast Pierre 
Published: May 2005

AbstractLaser Raman spectroscopy permits the study of black graphitic materials. Intercalated compound of first stage obtained with H2SO4 will be appear to contain the ion S2O72−. The frequencies of Raman active mode E2g2 of graphite network are in good agreement with this result. The interaction between graphitic plane and this intercalated molecule is weaker than in material obtained by action of HSO3F on graphite.
Raman study of hydrogen bonding in α and β‐oxalic acid dihydrate
Authors: Ebisuzaki Y. , Angel S. M. 
Published: May 2005

AbstractThe effects of different hydrogen bonding configurations upon the Raman spectrum of α‐(COOH)2·2H2O, α‐(COOD)2·2D2O, β‐(COOD)2·2D2O and (COOK)2·H2O and the temperature stability of β‐ (COOD)2·2D2O are reported. The OH stretch frequencies correlate well to the changes in the hydrogen bond length and the bond angle. The band width of the stretch frequencies, however, is not related to the hydrogen bond strength. The α phase of oxalic acid dihydrate is the more stable, low temperature form and the β crystals were observed to transform to the α phase.
Raman spectra of Br3− and I3− adsorbed on zeolites
Authors: Rubim J. C. , Sala O. 
Published: May 2005

AbstractThe Raman spectra of Br3− and I3− adsorbed on several zeolites were investigated in order to verify a previous assignment of bands, observed in the spectra of bromine and iodine adsorbed on zeolites, to the trihalide ions formed in the zeolites.
Raman spectroscopic studies of S16O2 and S18O2 in the gas phase: Hot band assignment
Authors: Brooker M. H. , Eysel H. H. 
Published: May 2005

AbstractRaman spectra have been obtained for the fundamental modes of S16O2 and S18O2 in the gaseous phase: S16O2, ν1=1151.3, ν2=518.2, ν3=1361.5; 18O2, ν1=1100.8, ν3=1318.0 cm−1. Band shapes for the isotopically different molecules are essentially identical and conform to expectations for a nearly prolate symmetric top molecule. Accurate isotopic shifts for a number of naturally abundant isotopically different molecules are reported. A weak peak shifted −3.1 cm−1 from the ν1 peaks of S16O2 and S18O2 has been assigned to the hot band transition 010→110. This assignment has been confirmed by temperature variation studies of S16O2 in CCl4 liquid.
Intensities of rotation and vibration‐rotation Raman transitions in asymmetric top molecules
Authors: Murphy William F. 
Published: May 2005

AbstractThe derivation of the intensities of rotation and rotation‐vibration Raman transitions for asymmetric top molecules is given, based on irreducible spherical tensor formalism. A computer program package written to calculate such intensities is described. Its use is demonstrated by reproducing the observed contours of the pure rotational band and the asymmetric stretching vibrational band in the Raman spectrum of the SO2 molecule. The polarizability tensor component ratio required to simulate the pure rotational contour is combined with literature values for mean polarizability and depolarization ratio to obtain the principal values of the SO2 polarizability tensor. A correlation of the polarizability tensor component ratio with band types is discussed for totally symmetric bands which have been reproduced using our program and those of others.
Totally symmetric progressions in resonance Raman spectra and excitation profiles
Authors: Samoc̀ Marek , Siebrand Willem , Williams Digby F. , Woolgar Eric G. , Zgierski Marek Z. 
Published: May 2005

AbstractThe intensity distribution in totally symmetric progressions in resonance Raman spectra and excitation profiles is re‐examined with the aim of removing remaining discrepancies between theory and experiment. New low‐temperature intensity data are reported on the permanganate ion in a perchlorate pellet. New calculations are reported on this ion as well as on β‐carotene in carbon disulfide solution. The main conclusion is that a careful consideration of lineshapes and line broadening mechanisms is required and that intensities in resonance Raman spectra must not automatically be equated in peak heights. It is shown that the remaining discrepancies in MnO4− are due to the neglect of the nontotally symmetric modes which are Jahn‐Teller active and affect the totally symmetric excitation profiles through a breakdown of the Condon approximation. The theoretical model used to analyze β‐carotene is improved by the introduction of Gaussian lineshapes associated with inhomogeneous line broadening.
Raman spectrum and torsional potential function for isoprene conformational enthalpy difference for 2‐cyclopropylpropene
Authors: Towns T. G. , Carreira L. A. , Irwin R. M. 
Published: May 2005

AbstractA polarized band at 223.7 cm−1 in the vapor phase Raman spectrum of isoprene has been observed and assigned to the 2‐0 transition of the vinyl torsion originating in the s‐cis conformation. This observation has been complemented with previously reported data to afford the determination of the vinyl torsional potential function in the formmagnified imageThe potential constants are (cm−1±2σ): V1=112±18; V2=2742±34; V3=294±18; and V4=−150±16. Modifications to a standard Spex model 1401 Raman spectrophotometer to allow digitization of spectra and automated operation are described in detail. The modifications have facilitated a precise deduction of the conformational enthalpy difference in both the liquid and the vapor states of 2‐cyclopropylpropene; they are, respectively, (cm−1±2σ)246±6 and 280±40. The results are discussed in terms of different mechanisms for resonance stabilization, particularly in light of a cyclopropyl group as one of the ‘conjugated’ moieties. The effect of a methine methyl‐substitution on the torsional potential function is discussed in terms of the hyperconjugation concept.
A cation dependent low frequency vibrational band in aqueous solutions of 5′‐guanosine monophosphate
Authors: Nielsen O. Faurskov , Lund P.‐A. , Petersen Steffen B. 
Published: May 2005

AbstractLow frequency Raman scattering of aqueous solutions of disodium‐5′‐guanosine monophosphate (GMP), dipotassium‐5′‐GMP, NaCl and KCl are studied by construction of a quantity R(ν). A band with a maximum at 115 cm−1 is assigned to a mode from mononucleotides, associated in a manner different from normal base stacking.
Experimental detection of the missing B1 mode in CuInS2 single crystal
Authors: Joshi N. V. 
Published: May 2005

AbstractThe missing low frequency B1 mode in a single crystal of CuInS2 has been experimentally detected for the first time. This mode is only Raman active; however, it was activated for infrared absorption process by introducing Fe impurity. The missing mode was investigated using Fourier transform spectroscopy. The experimentally observed value (110 cm−1) is in accordance with the theoretically predicted value.
Infrared, Raman and resonance Raman investigations of methylviologen and its radical cation
Authors: Forster M. , Girling R. B. , Hester R. E. 
Published: May 2005

AbstractThe infrared and Raman spectra of methylviologen (1,1′‐dimethyl‐4,4′‐bipyridine dication, MV2+) have been measured from both the solid dichloride and aqueous solutions. The preresonance behaviour of MV2+ Raman bands showed that the absorption at ˜196 nm is mainly responsible for the resonance scattering process in MV2+. In the region below 1700 cm−1, nine polarized (p˜1/3) resonance Raman bands of the methylviologen radical cation, MV+, were assigned to in‐plane ring modes. Arguments are given that the chromophore of MV+ may also partially include the methyl groups. The excitation profiles of the MV+fundamentals, measured with laser wavelengths covering the range 350.6–676.4 nm, reveal three main groups of modes, each behaving differently for the excitation in this range. Modes containing largely ν(CC) ring contributions are mainly coupled with electronic transitions at ˜395, ˜605 and ˜720 nm and yield simple excitation profiles. Modes involving principally the vibrations of the N+CH3 group show complicated interference peaks in the whole range of the excitation profiles. γ(CCC) is mainly coupled with the absorption at ˜620 nm. Resonance Raman bands of the (MV+)2 dimer have been characterized through studies of the concentration dependence of the spectra.
The 2ν4 isotropic and anisotropic Raman bands of CH4
Authors: Lolck Jens‐Erik , Brodersen Svend , Robiette Alan G. 
Published: May 2005

AbstractThe Raman spectrum of the very weak 2ν4 band of CH4 has been recorded in the region 2460–2675 cm−1 with a spectral resolution of about 0.30 cm−1 and with two different orientations of the linearly polarized exciting light relative to the direction of observation. The two exposures are used to obtain the purely isotropic and the purely anisotropic Raman spectrum of the band. The two spectra are interpreted in terms of a model which takes explicitly into account vibrational and rotation‐vibrational interactions with other vibrational states. Using molecular constants determined primarily from infrared spectroscopy, theoretical contours are calculated which agree very satisfactorily with the experimental ones. For the isotropic spectrum it is found that two different values of the ratio between the 2ν4(A1) and the ν1 transition moment matrix elements reproduce the spectrum equally well. It is shown that the major part of the intensity in the isotropic and anisotropic Raman spectrum is borrowed from the ν1(A1) and the ν3(F2) fundamentals, respectively, through Fermi‐type interactions, and it is also shown that the 2ν4 isotropic Raman band would have been 4–6 times more intense, if the 2ν4(A1) transition moment matrix element had been negligible.
Enhanced Raman scattering from molecular‐dye films on silver
Authors: Aroca Ricardo , Loutfy Rafik O. 
Published: May 2005

AbstractSurface enhanced Raman scattering has been observed for phthalocyanine films deposited on silver. Surface roughness or 'metal islands' seems to be crucial for large enhancement factors. Metal enhanced Raman spectra appear to show specific changes in the relative intensities of vibrations associated with the inner part of the macrocycle.
Analyse Vibrationnelle et Structurale en Série Aliphatique Saturée 4—Spectres de Vibration de I'Acide Diméthylmalonique et de ses Sels Alcalins en Solution Aqueuse
Authors: Delarbre J. L. , Maury L. , Bardet L. 
Published: May 2005

AbstractLes spectres de vibration (Raman et infrarouge) de l'acide dimétyhlmalonique et de ses sels alcalins en solution aqueuse (H2O et D2O) ont été anregistrés de 250 à 4000 cm−1. L' ananlyse de l'état de polaristion des raies Raman observées permet de conclure que l'acide diméthylmalonique et le sel neutre appartiennent au groupe C2 tandis que le sel acide répond au groupoe Cs, le plan de symétrie étant bissectrur du groupe COO−. Une attribution des raies observées aux vibrations fondamentales est proposée.
The resonance Raman spectrum of the 18O‐enriched MnO ion
Authors: Jubert A. H. , Varetti E. L. 
Published: May 2005

AbstractThe resonance Raman spectrum of the MnO ion enriched in 18O and dispersed in a RbBr matrix was obtained. The symmetric stretching fundamental band and its first three overtones were measured for the five possible isotopomers, allowing an estimation of the corresponding harmonic frequencies and anharmonicity constants. An explanation for the observed trend in these constants is proposed.
The Raman spectra of BH and BD isolated in alkali halides at 80 K
Authors: Memon M. I. , Sherman W. F. , Wilkinson G. R. 
Published: May 2005

AbstractRaman spectra of BH and BD ions isolated in alkali halides are presented. Effects produced by changing the supporting lattice and by 10B to 11B and H to D isotopic substitution are discussed. The need for a careful analysis of the Fermi resonance that is an important feature of these spectra is explained.
An investigation of the lattice and interlayer water vibrational spectral regions of muscovite and vermiculite using Raman microscopy. A Raman microscopic study of layer silicates
Authors: Haley L. V. , Wylie I. W. , Koningstein J. A. 
Published: May 2005

AbstractThe micro Raman spectrum of ∼100fg of the clay materials Muscovite and Vermiculite in the region of 600 cm−1 −3300 cm−1 is reported. An attempt has been made to assign the observed Raman shifts in particular those of H‐bonded OH−, which may have significance to an understanding of the role which clay plays in the absorption of soil water.
The vibrational spectra and normal co‐ordinate analysis of NaOX (X = H or D)
Authors: Kanesaka Isao , Tsuchida Masaaki , Kawai Kiyoyasu 
Published: May 2005

AbstractThe vibrational spectra of NaOX (X = H or D) at room temperature and 77 K are reported. A normal co‐ordinate analysis has been carried out to assign the observed bands on the basis of the valence force field. The force constants were adjusted by considering a bond distance and reproduce well the observed frequencies. In the dispersion relations on k2 and kx the librational modes were found to be insensitive to k, whereas the translational modes except for the A1g and B1u modes vary considerably with k. Some bands were assigned to the combination band between a fundamental and an acoustic mode.
Temperature dependence of Raman active modes in triethylenediamine
Authors: Sauvajol J. L. 
Published: May 2005

AbstractThe temperature dependence of Raman active modes in monocrystalline Triethylenediamine has been studied by Raman spectroscopy. The linewidths and frequencies of these modes have been measured in the temperature range 110‐330 K (that is the low temperature phase for which T < Tc = 351 K). A strong broadening is observed at higher temperatures in this range for the A2 and E1g librons. This can be related to the activation of disorder in the low temperature phase.
On the nature of the lowest excited states of styrene: Calculation of the resonance Raman spectrum and pre‐resonance profiles
Authors: Marconi G. 
Published: May 2005

AbstractThe nature of the low‐lying excited single states of styrene has been investigated through calculation of the resonance Raman spectrum and pre‐resonance Raman profiles of the three modes of CC stretching nature. A reasonable agreement with experiment is found and an analysis of the main contributions to the intensity is provided in terms of vibronic matrix elements. The possibility of destructive interference of diagonal and off‐diagonal terms is analysed for the three modes examined.
Plasmon‐phonon coupling effects in picosecond Raman scattering of nonequilibrium semiconductor plasma
Authors: Vasconcellos A. R. , Luzzi R. 
Published: May 2005

AbstractThe ultra‐fast time‐resolved Raman spectra of a highly photoexcited semiconductor plasma is calculated. Information is provided on the time‐evolution of irreversible relaxation processes that develop in the system. It is described how plasmon‐phonon interference effects in the Raman spectra are affected in the far‐from‐equillbrium state of the system. We used a theoretical method, based on a generalization of Gibbs algorithm to nonequilibrium situations, and a numerical analysis appropriate for the case of GaAs samples is presented.
Magnetic electronic Raman optical activity of osmium (IV) hexabromide, iridium (IV) hexachloride and uranocene
Authors: Barron L. D. , Vrbancich J. 
Published: May 2005

AbstractMagnetic optical activity is reported in electronic resonance Raman transitions of OsBr, IrCl and U(C8H8)2 in solution. All the effects are observed in the form of couplets which originate in separate Raman transitions between magnetic components of the initial and final levels. These can give detailed information about the magnetic structure of the ground and low‐lying electronic states, particularly the sign of the g‐factor and the ordering of magnetic sub‐states in general. For example, effects in the 466 cm−1 electronic Raman band of U(C8H8)2 confirm that the MJ = ±4 level lies below the MJ = ±3 level. We also use the magnetic Raman optical activity to identify a very weak U(C8H8)2 Raman band at 675 cm−1 with a vibrational‐electronic combination transition.
Absence of surface enhanced Raman scattering (SERS) by pyridine on cleaned roughened silver electrodes
Authors: Mernagh Terrence P. , Cooney Ralph P. 
Published: May 2005

AbstractAnodically roughened silver electrode surfaces which have been cathodically cleaned exhibit virtually no pyridine surface spectrum i.e. no surface enhanced Raman scattering (SERS) effect. Scanning electron microscopy (SEM) reveals no detectable change in the surface roughness features as a result of the cathodic surface cleaning. The absence of SERS has been confirmed for cathodically‐cleaned flat (unanodized), roughened (anodized) and massively roughened (repetitively anodized) silver surfaces. These findings appear to rule out flat‐surface or roughened‐surface (metal‐particle) enhancement of the pyridine spectrum itself. Other evidence confirms that the intensely scattering SERS phase is [carbon‐pyridine] and not pyridine itself. The carbon and pyridine SERS intensities are shown to coincide on the potential scale and to exhibit a stoichiometric interdependence. These results rule out coadsorption and argue strongly in favour of internal trapping rather than external adsorption of pyridine on carbon. The insensitivity of pyridine SERS to the presence of a radical scavenger confirms the absence of radical ion resonance enhancement. These results are consistent with parallel Auger studies which reveal that localized laser damage (producing a zone of pure carbon in the case of pyridine) is probably the primary factor in SERS from silver electrodes. The implications of these and other results for a reduced silver‐generated enhancement factor are considered.
Comments on the use of BOXCARS for gas‐phase CARS spectroscopy
Authors: Greenhalgh Douglas A. 
Published: May 2005

AbstractCalculations of integrated intensity and 90% interaction length have been performed for planar and folded BOXCARS phase matching schemes for gas‐phase Coherent Anti‐Stokes Raman Scattering (CARS). These results show that, in general, for a half crossing angle of the pump laser beams of less than 20 degrees there is no difference between folded and planar BOXCARS. Further, the calculations indicate that the optimum Stokes beam diameter is 2/3 of the pump beam diameter; this result is also true for colinear CARS. The calculations also show that the interaction length can be accurately estimated from a simple geometric formula. The adaptation of planar and folded BOXCARS for ‘single‐ended’ operation (input and signal beams transmitted through the same observation window) is outlined and discussed.