bluuebunny/crossref_metadata_2025_split huggingface dataset:
Excitation profiles and depolarization ratios of some prominent Raman lines in oxyhaemoglobin and ferrocytochrome c in the pre‐resonant and resonant region of the Q‐band
Authors: Schweitzer‐Stenner R. , Dreybrodt W. 
Published: May 2005

AbstractThe depolarization ratio‐dispersion curves and the excitation profiles of oxyhaemoglobin (1375, 1583, 1638 cm−1) and ferrocytochrome c Raman lines have been measured in the pre‐resonant and resonant regions of the Q‐band, respectively. The experimental data are interpreted by fifth‐order Loudon theory of the polarizibility tensor, including symmetry lowering of the haem group and the creation and subsequent annihilation of a second phonon. The fitting constants needed to fit the experimental data are related to vibronic coupling matrix elements due to the Raman and the second phonon. They also contain distortions δQΓ, lowering the ideal D4h, symmetry of the functional haem group. These distortions can be classified due to the Raman‐allowed representations A1g, B1g, B2g and A2g in D4h symmetry. Thus, from the fitting procedure one obtains detailed information about the actual symmetry of the haem group.
The use of compacted metal discs to measure Raman spectra
Authors: Nimmo J. A. , Bovill A. J. , McConnell A. A. , Smith W. E. 
Published: May 2005

AbstractCompacted discs prepared from a mixture of finely divided particles of a compound diluted in a large excess of metal powder facilitate the measurement of Raman spectra for some compounds which give poor scattering by conventional techniques. The method is most useful with coloured compounds. The advantages include simplicity, increased signal‐to‐noise ratio by factors of up to 1000 and decreased or altered fluorescence. The effect appears to be caused mainly by small crevices in the compacted metal surface which act as internal mirrors to produce many small multiple‐reflection cells, but there is also evidence of an electronic interaction with the metal surface. Silver, aluminium and copper matrices were studied, silver being found to be the most advantageous, although aluminium under certain conditions may also be effective.
The resonance Raman spectra of some cyanine dyes
Authors: Yang J.‐P. , Callender R. H. 
Published: May 2005

AbstractThe resonance Raman spectra of a series of cyanine dyes, with various lengths of the methine chain, have been obtained. This series consists of the 1,1′‐diethyl‐2,2′‐quino group basic structure. Raman spectra of some dyes with closely related structures were also measured. The Raman bands are assigned to normal modes arising from particular molecular moieties. For comparison purposes, the IR spectra of these dyes are also presented.
Effect of the damping constant on Raman excitation profiles
Authors: Lee Soo‐Y. , Chow King‐Sum 
Published: May 2005

AbstractRaman scattering is treated using the displaced harmonic oscillator model. The time‐dependent approach to the Raman scattering tensor was adopted and the exact propagation of gaussians on harmonic surfaces was exploited. An insight into the effect of the damping constant on the Raman excitation profiles was thus obtained. It is shown that the dynamics of the wavepacket propagation on the excited state surface governs the difference between continuum resonance Raman scattering and discrete resonance Raman scattering.
Raman spectra of I4O9 formed by the reaction of iodine with ozone
Authors: Sunder S. , Wren J. C. , Vikis A. C. 
Published: May 2005

AbstractThe Raman spectrum of I4O9, formed by the gas‐phase reaction of I2 with O3, has been measured. Freshly prepared samples of I4O9 gave broad band spectra characteristic of an amorphous solid. Vibration bands at 780, 740, 620 and 450 cm−1 were observed. It was established conclusively that I4O9 is a distinct molecular species and not a mixture of I2O5 and I2O4.
Raman difference spectroscopy via backscattering from a spinning tube and from a low‐temperature tuning fork
Authors: Eng John F. , Czernuszewicz Roman S. , Spiro Thomas G. 
Published: May 2005

AbstractTwo novel devices for difference Raman spectroscopy are described. In one, an NMR tube is fltted with a PTFE divider to permit difference spectroscopy via the convenient spinning tube backscattering arrangement. The other device is a tuning fork, equipped with a pair of sample cups, attached to a cold finger, to permit acquisition of difference spectra on small samples of frozen solutions. This provides a particularly convenient method for low‐temperature difference spectroscopy.
Molecular reorientation of liquid trimethylchlorosilane from Raman band shape studies
Authors: Steiger Th. , Brzezinka K.‐W. , Reich P. 
Published: May 2005

AbstractMolecular reorientation of liquid trimethylchlorosilane (TMC) has been studied by means of Raman band shape analysis for the temperatures 298, 246 and 218 K. Experimental correlation times were compared with NMR relaxation time measurements and with diffusional and hydrodynamic models. Information theory was used to predict C(1)(t) given C(2)(t).
Raman spectra of the human lens in relation to pathology and the anticataract effect of drugs
Authors: Bertoluzza A. , Fagnano C. , Monti P. , Caramazza R. , Cellini M. 
Published: May 2005

AbstractRaman spectroscopy has been used for ophthalmological studies. Results obtained with traditional Raman instrumentation on animal and human lenses (normal and cataracted) and on the action of anticataract drugs are presented and discussed.
High‐resolution Raman investigation of the vibrational relaxation of two‐phonon bound states in solid CO2 at different temperatures
Authors: Ranson P. , Ouillon R. , Califano S. 
Published: May 2005

AbstractThe Raman spectra of the bound states Ω+ and Ω− of the Fermi diad ω1:2ω2 in crystalline CO2 have been measured at several temperatures under very high resolution. Band profiles have been determined for each of the two factor group components, one Ag and one Fg, of the two states.The evolution with temperature of the bandwidths has been interpreted in terms of four‐phonon decay processes. A single down‐process, involving a lattice phonon at 60 cm−1, is shown to be sufficient to reproduce the experimental data for the Ω+ state. In the same way, a single up‐process, involving the same lattice phonon, is sufficient to fit the experimental data for the Ω− state. The variation of the factor group splitting of the Ω− component as a function of temperature has also been determined.
Coherent Raman spectroscopy of glyoxal vapour
Authors: Duval A. B. , King D. A. , Haines R. , Isenor N. R. , Orr B. J. 
Published: May 2005

AbstractThe coherent Raman spectroscopic techniques CARS and PARS have been used to study glyoxal (C2H2O2) in the vapour phase. The following fundamental vibrational frequencies for trans‐glyoxal have been determined: ν1 = 2840 ± 2, ν2 = 1742.5 ± 0.5 and ν3 = 1353.5 ± 0.5 cm−1. Several hot and combination bands have also been identified. The rovibrational contour of the ν2 band is unexpectedly broad and structured and a variety of possible sources of this apparent anomaly are investigated. Novel experimental strategies include simultaneous recording of CARS and PARS spectra, major variations of pump and Stokes wavelengths to eliminate resonantly enhanced processes and rotationally resolved Raman–optical double resonance spectroscopy.
Vibrational spectra and structure of halogen‐substituted cyclopropanes. III—cis‐ and trans‐1, 2‐diiodocyclopropane
Authors: Schrumpf G. 
Published: May 2005

AbstractThe infrared spectra of liquid cis‐ and trans‐1, 2‐diiodocyclopropane were measured from 4000 to 200 cm−1. Raman spectra between 4000 and 50 cm−1 of the two compounds as liquids and of the solid cis isomer were also obtained. All of the 21 normal vibrations of the two molecules were convincingly assigned on the basis of Raman depolarization ratios and group frequency correlations. Comparisons are made with the normal modes of related compounds. There is excellent agreement with those assignments previously proposed for the two isomers of 1, 2‐dibromocyclopropane, cis‐1, 2‐dichlorocyclopropane and related modes of iodocyclopropane.
Intensity measurement of resonance Raman spectra of adsorbed dyes by the divided disc method
Authors: Tsukamoto Ikuko , Machida Katsunosuke 
Published: May 2005

AbstractThe divided disc method was utilized for the measurement of the resonance Raman intensities of adsorbed dyes. Only one band of crystal violet exhibits appreciable change in its relative intensity when adsorbed on silica gel. The spectral features of the adsorbed crystal violet are similar to those reported for the SERS spectrum of the dye adsorbed on a silver electrode. The resonance Raman spectrum of the adsorbed methyl orange resembles that of the protonated dye crystallized from acidic solution, but the intensities are considerably enhanced on adsorption. From the spectral pattern, the adsorbed methyl orange was proved to take the same azonium form as was reported as the SER scatterer. The Raman scattering coefficients of the CC stretching band of methyl orange excited at 488.0 and 514.5 nm were proved to be enhanced on adsorption of silica gel by factors of ca 50 and 100, respectively.
FT‐IR and micro‐Raman spectra of some group IVB and VIB organometallacyclo‐sulfanes and ‐selenanes
Authors: Butler Ian S. , Harvey Pierre D. , McCall James M. , Shaver Alan 
Published: May 2005

AbstractThe FT‐IR and micro‐Raman spectra of the solid Group IVB and VIB metallacyclo‐sulfanes and ‐selenanes, Cp2ME5 (Cp = η‐C5H5; M = Ti, Zr, Hf; E = S, Se), (η‐C5Me5)2MS3, Cp2MS4 (M = Mo, W) and Cp2MoS2 have been recorded and assignments are presented for the cyclopentadienyl ligand vibrations and some of the low‐energy modes associated with the metal‐chalcogen moieties. This is the first time that attempts have been made to identify the ZrS, HfS, TiSe, ZrSe, and HfSe stretching modes in such metal chelates. For the polysulfane complexes, the peaks attributed to the symmetric ν(SS) stretching modes decrease in energy with increasing size of the catenated metal‐sulfur ring and so it appears that vibrational spectroscopy can be used to distinguish between the four different ring sizes. For the polyselenanes, an empirical relationship (similar to that already known for S‐S vibrations) relating the wavenumber of the symmetric ν(SeSe) stretch and the Se‐Se bond length is proposed.
Infrared and Raman spectra of 2,3‐dimethylaniline
Authors: Shukla A. R. , Pathak C. M. , Dongre N. G. , Asthana B. P. , Shamir Jacob 
Published: May 2005

AbstractThe infrared spectra of 2,3‐dimethylaniline in different phases have been recorded in the region 4000–100 cm−1. In the solid phases at 223 and 123 K, however, the spectra were recorded in the region 4000–400 cm−1 only. Raman spectra with polarization measurements have been recorded and investigated for the first time. New frequency assignments are proposed, assuming the molecule to possess an approximate Cs symmetry; 52 out of a possible 54 normal modes in the molecule have been observed and assigned, including 25 hitherto unreported modes. The observed spectral changes give evidence of a solid‐solid phase transition in the molecule between 223 and 123 K and indicate the presence of intermolecular hydrogen bonding due to the presence of an amino group in the molecule.
Raman spectra of orthorhombic sulfur at 40 K
Authors: Harvey Pierre D. , Butler Ian S. 
Published: May 2005

AbstractHigh–quality Raman spectra of orthorhombic sulfur (S8) have been recorded at 40 K employing multiscanning conditions. Assignments are proposed for the many new features detected, especially binary and ternary overtones and combinations of the SS stretching and SSS bending vibrations. The anharmonicities of these particular modes are shown to be fairly small.
Incommensurate phase in tetramethylammonium tetrachlorozincate: Evidence from internal modes
Authors: Pal Mahendra , Agarwal Anshu , Khandelwal D. P. , Bist H. D. 
Published: May 2005

AbstractTemperature‐dependent vibrational Raman studies of tetramethylammonium tetrachlorozincate [(TMA)2ZnCl4] are reported together with the assignments of the observed bands in all the six polarization geometries at room temperature in phase I, which is orthorhombic with a space group D2h16 (Z=4). Existence of the well known incommensurate phase with wave vector κ = 2/5+δ in the temperature range 296.6–280.9 K is supported by the abnormal intensity behaviour of modes of species A1 (under the point group symmetry Td for TMA and ZnCl4 ions) in X(ZZ)Y and X(YZ)Y polarization geometries. The observed intensity behaviour could be explained on the assumption that the orientations of TMA and ZnCl4 ions are governed by the incommensurate modulation in the Z‐direction.
Analyse Vibrationnelle et Structurale en Série Aliphatique insaturée–Spectres de Vibration de l'Acide Acétylènedicarboxylique et de ses Sels Alcalins en Solution Aqueuse
Authors: Delarbre Jean Louis , Maury Luc , Bardet Lucette 
Published: May 2005

AbstractLes spectres Raman et infrarouge des acides acétylènedicarboxylique H2C4O4 D2C4O4 et de leurs sels alcalins KHC4O4, KDC4O4 et K2C4O4 ont été enregistrés de 3000 à 200 cm−1. L'analyse du facteur de dépolarisation nous a permis de conclure que I'acide, le sel acide et le sel neutre sont de symétries respectives C2h, CS et D2d. Une comparaison des conformations avec celles déterminées en série oxalique a été réalisée. Une attribution des vibrations fondamentales est proposée.
Fluorescence rejection in Raman spectroscopy using a gated intensified diode array detector
Authors: Everall N. , Jackson R. W. , Howard J. , Hutchinson K. 
Published: May 2005

AbstractA system consisting of a mode‐locked and cavity‐dumped picosecond laser and gated (5 ns) intensified diode array detector has been used to evaluate the potential of diode arrays as detectors in fluorescence rejection measurements of Raman spectra. Successful fluorescence rejection was observed, but both the level of rejection and the signal‐to‐noise improvement observed would be substantially improved if the operating characteristics of the laser system and of the array were different. It was demonstrated that the diode array opens several times, at intervals of ca 15.5 ns, for each trigger pulse supplied.
The pure rotation Raman spectrum of 17O18O
Authors: Edwards H. G. M. , Long D. A. , Najm K. A. B. 
Published: May 2005

AbstractThe pure rotation Raman spectrum of 17O18O has been recorded photographically using laser excitation and a spectrograph with a reciprocal linear dispersion of 1.4 cm−1 mm−1 at 488.0 nm. The following B0, D0 and r0 values were obtained; B0=1.31546±0.00002 cm−1, 106D0=3.50±0.05 cm−1 and r0=121.072±0.002 pm.
Raman and far‐infrared study of the lattice vibrations of methyl cyanide
Authors: Anderson A. , Zeng W. Y. 
Published: May 2005

AbstractLow‐frequency Raman and far‐infrared spectra of both solid phases of CH3CN and CD3CN at temperatures between 20 K and the melting point have been recorded. Assignment of the observed peaks as librations about the principal molecular axes or as translational modes is facilitated by finding the frequency ratios of corresponding peaks for CH3CN and CD3CN. The spectra are compared with group theoretical predictions, based on possible space groups for each of the two phases. It is found that a unit cell with point group C2h and four molecules on general sites is favoured for phase I. The lattice spectra do not appear to be compatible with the larger unit cell proposed for phase II.
Molecular interactions between electrophiles and nucleic acids. I—Raman spectroscopic study of the molecular reactivity of three typical methylating agents
Authors: Bertoluzza A. , Fagnano C. , Morelli M. A. , Tosi R. 
Published: May 2005

AbstractThree methylating agents with different carcinogenic powers, dimethyl sulphate [(CH3O)2SO2 (DMS)], methyl methanesulphonate [CH3SO2OCH3 (MMS)] and N‐methyl‐N‐methyl‐N‐nitrosourea [CH3N(NO)CONH2 (MNU)], were studied by Raman spectroscopy in order to identify the reactive species which are formed in buffered aqueous solution at neutral pH.In all cases, the formation of methanol was observed. By hydrolysis DMS produces CH3OSO3−, and H3O+ ions, and MMS produces CH3SO3− and H3O+ ions. In the case of MNU the reaction is more complex and proceeds with gaseous products to give methanol quantitatively.This investigation is a preliminary to the study of molecular interactions between the three methylating agents and nucleic acid components.
Resonance Raman investigation of iodine and bromine adsorbed on porous vycor glass
Authors: Favre Pierre , Jayasooriya Upali A. , Powell Donald B. 
Published: May 2005

AbstractResonance Raman spectra have been recorded for bromine and iodine supported on the surface of porous Vycor glass. They show that the halogens are mainly physisorbed on the Vycor glass. Other features indicate the presence of polyhalide species of type X3−. When the amount of polyhalide is large, we observe peaks which can be attributed to a halogen molecule coordinated to a Lewis base, which is probably X3−.
Use of time‐resolved Raman spectroscopy for measuring mixing times and concentrations
Authors: Cook B. W. , Louden J. D. , Lorriaux‐Rubbens A. , De Kerangue L. Nouël , Bridoux M. , Wallart F. 
Published: May 2005

AbstractTime‐resolved Raman spectroscopy (TRRS) is presented as a non‐invasive technique for measuring mixing/concentration profiles in a fully baffled disc turbine‐agitated tank.
Surface‐enhanced Raman scattering (SERS) of aromatic amino acids and their glycyl dipeptides in silver sol
Authors: Kim Sang Kyu , Kim Myung Soo , Suh Se Won 
Published: May 2005

AbstractThe surface‐enhanced Raman (SER) spectra of aromatic amino acids (L‐phenylalanine, L‐tyrosine and tryptophan) and their glycyl dipeptides (glycyl‐L‐phenylalanine, glycyl‐L‐tyrosine and glycyl‐L‐tryptophan) adsorbed on Ag colloidal particles have been obtained. The surface‐enhanced and ordinary Raman spectra show satisfactory correlations. The most prominent features in the SER spectra of all compounds are the strongly enhanced peaks at about 930 and 1390 cm−1 due to the CCOO− stretching and COO− symmetric stretching vibrational modes, respectively. This is interpreted as suggesting that the above compounds are adsorbed on the Ag surface through the carboxylate group. In the SER spectrum of glycyl‐L‐phenylalanine, the amide I and II bands are observed at about 1670 and 1520 cm−1, respectively.
Vibrational spectra of and phase transitions in caesium hydrogen sulphate
Authors: Pham‐Thi M. , Colomban Ph. , Novak A. , Blinc R. 
Published: May 2005

AbstractThe Raman and infrared spectra of the superionic protonic conductor CsHSO4(CsDSO4) were investigated in the 18–450 K range. Polarized single crystal Raman and infrared reflection spectra were also studied at room temperature. An assignment of bands due to internal and external vibrations is given in terms of symmetry species and approximate type of motion. The spectroscopic results, in particular the behaviour of the Raman bands as a function of temperature, are used to discuss the crystalline structures of various phases, hydrogen bonding, the type and degree of structural disorder, phase transitions and conductivity.
Resonance Raman studies of guanine derivatives
Authors: Chinsky L. , Jollès B. , Laigle A. , Turpin P. Y. 
Published: May 2005

AbstractUltraviolet resonance Raman spectra of some guanine derivatives in aqueous solutions are reported, viz. guanosine, N1 ‐methylguanosine, N2 ‐methylguanosine and N2, N2 ‐dimethylguanosine. The effects of deuteriation were also investigated. The vibrational patterns of guanosine and the derivatives are complicated, since they involve contributions from both the pyrimidine and imidazole rings. However, the understanding of the spectral features is of special interest since some bands are highly sensitive to the B to Z conformational transition of alternating dG‐dC sequences containing DNA. From these UV resonance Raman spectra, assignments of the principal modes of vibration are proposed and discussed in relation to the results of normal coordinate calculations previously performed by other workers.
Raman and far‐infrared spectra of crystalline methylene iodide
Authors: Torrie B. H. , Anderson A. , Andrews B. , Laurin D. G. , White J. K. , Zung W. W. E. 
Published: May 2005

AbstractThe lattice vibrations and internal modes of polycrystalline CH2I2 and CD2I2 have been studied as a function of temperature using Raman and far‐infrared spectroscopy. CH2I2 has two stable phases, one of which is metastable in the temperature range of the other, and a second metastable phase. CD2I2 has only one solid phase. Possible structures for the various phases are discussed.
Polarization measurements in Raman microspectroscopy. I—Isotropic samples
Authors: Brémard Claude , Laureyns Jacky , Merlin Jean‐Claude , Turrell George 
Published: May 2005

AbstractA quantitative analysis is made of the problem of obtaining accurate polarization measurements in Raman microspectroscopy. The introduction of experimentally determined correction factors arising from the optical properties of the beam splitter allows the depolarization by the microscope objective to be studied separately. Correction curves are calculated for the various parameters which characterize the light‐excitation path and the light‐collection path. These parameters are functions of both the numerical aperture of the objective and the refractive index of the (isotropic) sample. The introduction of these parameters into the expressions for the depolarization ratios of various Raman and resonance Raman bands accounts well for the differences noted between the results of the present microprobe measurements and those obtained with conventional instruments. The values determined here are, within experimental error, in agreement with the calculated results over a large range of depolarization ratios.
Spectroscopic evidence for resin‐reinforced dentine by a Raman microprobe technique
Authors: Suzuki Masako , Kato Hiromasa , Wakumoto Sadao , Katagiri Gen , Ishitani Akira 
Published: May 2005

AbstractA Raman microprobe technique was applied to analyse the chemical components at the interface layer between dental adhesive resins and dentine. Raman spectra from each spot (ca. 2 μm in diameter) on the flat surface perpendicular to the interface were measured individually. These spectra indicate the coexistence of the resin and dentine components in a thin layer (ca. 5 μm in depth) of the dentine side. This provides spectroscopic evidence for the formation of resin‐reinforced dentine.
Method for the automatic determination of laser beam polarization and intensity parameters for the measurement of Raman optical activity
Authors: Gunnia Uma , Davies Mark A. , Diem Max 
Published: May 2005

AbstractA method for the quantitative determination of the laser beam deflection on passage through an electro‐optic modulator is presented. The hardware used to determine simultaneously the beam polarization parameters and deflections is described, and a procedure for minimizing these deflections is outlined. Examples of artifacts caused by the motion of the laser beam in the observation of Raman optical activity are presented.
Laser Raman study of phase transitions in [N(CH3)4]2COCl4 single crystals
Authors: Rathore R. P. , Khatri S. S. , Chakraborty T. 
Published: May 2005

AbstractTemperature‐dependent Raman spectra of oriented single crystals of [N(CH3)4]2CoCl4 are reported. An assignment of the observed Raman bands has been made and it was found that the N(CH3)4+ and CoCl42− groups occupy sites of Cs symmetry in the lattice at room temperature. However, because of rapid reorientation, the CoCl42− groups retain an effective tetrahedral symmetry. The prototypic to incommensurate to commensurate phase transitions are associated with the orientational dynamics of the CoCl4 tetrahedra. The monoclinic to orthorhombic super lattice phase transition at 122 K in [N(CH3)4]2CoCl4 is triggered by the distortion of the N(CH3)4+ groups in the lattice.