bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accurate spectroscopic constants of nitrogen determined from stimulated Raman spectra of the fundamental and first hot bands
Authors: Tabyaoui A. , Lavorel B. , Millot G. , Saint‐Loup R. , Chaux R. , Berger H. 
Published: May 2005

AbstractNitrogen spectra of the Q‐branch of the fundamental and the first hot bands were recorde with a high‐resolution stimulated Raman spectrometer at atmospheric pressure and ca. 1300 K. The absolute frequencies of the Raman lines were measured with high accuracy, leading to a refinement of spectroscopic constants. A temperature estimation was also performed from the Raman intensities.
Comparison of different phase conjugate and backscattering arrangements in non‐linear Raman spectroscopy
Authors: Pfeiffer M. , Lau A. , Werncke W. 
Published: May 2005

AbstractA theoretical and experimental comparison of coherent anti‐Stokes Raman scattering (CARS) and Raman‐induced phase conjugation (RIPC) techniques has been carried out. In most cases the RIPC techniques are much more sensitive than CARS to deviations from the phase‐matching conditions, from which it follows that for RIPC much higher accuracy of the alignment and optical homogeneity are necessary. In practice, only one RIPC variant with nearly copropagating pump waves and contrapropagating Stokes waves is applicable to obtain complete spectra. A CARS reflection technique is discussed for the investigation of highly absorbing samples.
Excitation profile study of the resonance CARS spectrum of pyrene in the S1 state for elucidating vibronic coupling
Authors: Akamatsu Naotoshi , Kamisuki Toshio , Adachi Yukio , Hirose Chiaki , Maeda Shiro 
Published: May 2005

AbstractResonance CARS excitation profiles of b3g vibrations of pyrene‐h10 and pyrene‐d10 in the lowest excited singlet (S1) state were obtained in the S10, S11 ← S1 transition absorption region. Analysis of the results showed that the vibrational mode at 1433 cm−1 is the major participant in the vibronic coupling between the higher resonant states S10(Ag) and S11(B3g) (B term), while the vibronic coupling of the lower S1(B2u) and S2(B1u) states (C term) makes a significant contribution to the resonance of the mode at 1553 cm−1. The electronic configurations of the higher excited states are discussed on those bases.
High‐precision femtosecond CARS of simple liquids
Authors: Fickenscher M. , Laubereau A. 
Published: May 2005

AbstractA novel non‐degenerate CARS spectrometer is described with an 80‐fs time resolution, improved measuring accuracy of ca. 1% for the vibrational dephasing time and adjustable frequency positions of the input pulses. Experimental data are reported for CH stretching vibrations of acetone, acetonitrile and bromoform. Negligible inhomogeneous broadening (<4%) is deduced from the observed exponential decay for the vibrational transitions. The effect of orientational motion on the dephasing observations is discussed.
Vibrational studies and molecular motions in tetramethylammonium perchlorate
Authors: Mylrajan M. , Srinivasan T. K. K. 
Published: May 2005

AbstractInfrared and single‐crystal Raman spectra (20–5000 cm−1) of (CH3)4NClO4 were studied in the temperature range 90–320 K. Low‐temperature vibrational studies at 90 K indicated freezing out of the disorder of the anions with an increased number of molecules.
Polarized Raman and infrared spectra of OH stretching vibrations in the sucrose crystal
Authors: Giermańska J. , Szostak M. M. 
Published: May 2005

AbstractThe bands corresponding to the eight OH stretching vibrations of the sucrose molecule in the crystal were identified using polarized IR and Raman spectra. They were assigned to the individual vibrations on the basis of the dichroic ratio calculations and evaluation of force constants by the Lippincott‐Schroeder model for seven hydrogen‐bonded OH groups. An explanation of the Raman activity of OH vibrations is proposed. A relationship between the anharmonicity of two OH oscillators and the gyrotropy of the crystal is suggested.
Raman and infrared spectra, barriers to internal rotation, vibrational assignments and ab initio calculations on 2‐fluoropropane
Authors: Durig J. R. , Nanaie H. , Guirgis G. A. 
Published: May 2005

AbstractThe Raman (3500‐20 cm−1) and infrared (3500‐50 cm−1) spectra of gaseous and solid 2‐fluoropropane, (CH3)2CFH, the corresponding trideuterated molecule, (CH3)(CD3)CFH, and heptadeuterated species, (CD3)2CFD, were recorded. Additionally, the Raman spectra of the pure liquids were recorded and qualitative depolarization values were obtained. All 27 of the normal vibrational modes were assigned for all three isotopic species based on infrared band contours, depolarization values, isotopic shifts and group frequencies. The vibrational assignment is supported by an ab initio calculation utilizing the 3‐21G basis set to obtain the force constants and potential energy distribution. Additionally, ab initio calculations were carried out utilizing the 6‐31G* basis set to obtain structural parameters and barriers to internal rotation. All of these results are compared with the experimentally determined values and with the corresponding results for some related molecules.
Vibrational spectroscopic study of L‐arginine phosphate monohydrate (LAP), a new organic non‐linear crystal
Authors: Dhanaraj G. , Srinivasan M. R. , Bhat H. L. 
Published: May 2005

AbstractL‐Arginine phosphate monohydrate (LAP) is a recently discovered organic non‐linear crystal which has the potential to replace a conventional crystal such as potassium dihydrogen phosphate. The polarized Raman and infrared spectra of a single crystal of LAP have been recorded to determine the symmetries of the molecular vibrations. The lattice lines are fairly strong compared with the others and show pronounced intensity variations with the orientation of the crystal. The high‐frequency lines are assigned to the vibrations of the various molecular groups such as NH3+, NH2+, NH2, CH2, CH, COO−, H2O and H2PO4− present in the crystal.
Dinucleotide binding to RNase probed with UV resonance Raman spectroscopy
Authors: Molina Marina , Wang Y. , Purrello R. , Spiro Thomas G. 
Published: May 2005

AbstractRaman spectra are reported for ribonuclease and its complexes with the dideoxynucleotides dCpdC, dCpdA and dCpdG, using 240–250‐nm excitation to enhance the purine and pyrimidine modes, as well as tyrosine and phenylalanine modes of the protein. Spectral perturbations associated with binding were examined via difference spectroscopy. Consistent with the crystal structure of CpA* bound to RNase, the 3′‐cytidine was inferred to be hydrogen bonded to a protein donor via the N‐3 ring atom, but not via the carbonyl O atom, since the 1526 cm−1 band shifts up on binding, as it does when aqueous CMP is protonated, and the CO stretch shifts from 1655 to 1670 cm−1, an effect attributable to polarization via the N‐3 hydrogen bond. The effect of binding on the spectra of the 5′‐purine rings is limited to intensity changes, an augmentation of the adenine 1578 cm−1 band and a diminution of the guanine 1330 cm−1 band, consistent with only weak interactions with the protein. Binding of dCpdC intensifies the 1615 cm−1 protein band, suggesting environmental changes for tyrosine or phenylalanine residues. No spectral perturbation was observed on mixing RNase with dGpdC or dGpdG, consistent with weak or non‐specific binding of dinucleotides lacking a pyrimidine in the 3′‐position.
Effect of doping on the Raman modes in MgO‐doped lithium niobate crystals
Authors: Hu L. J. , Chang Y. H. , Hu M. L. , Chang M. W. , Tse W. S. 
Published: May 2005

AbstractRaman spectra of a series of MgO‐doped congruent LiNbO3 crystals were obtained with MgO concentrations up to 30 mol.%. Single crystals were successfully grown and no precipitates were discovered. The intensity, frequency and line width of the Raman phonons were studied as a function of doping percentage. An abrupt change was observed near the composition of 7.5 mol.% of MgO‐doped LiNbO3 crystal. From the spectral changes it is proposed that Mg2+ replaces the mis‐sited Nb5+ cation at Li sites first. When these mis‐sited Nb5+ cations have been completely replaced, the Mg2+ cation then replaces the Li+ cation and creates vacancies at Li+ sites.
Raman scattering investigations of KY3F10
Authors: Mortier M. , Gesland J. Y. , Rousseau M. , Pimenta M. A. , Ladeira L. O. , Da Silva J. C. Machado , Barbosa G. A. 
Published: May 2005

AbstractSingle crystals of the fluoride compound KY3F10 (Oh5) were studied by Raman scattering from 40 to 950 K. Group theory analysis predicts 3A1g + 4Eg + 6F2g Raman‐active modes, but the experimental spectra show two F2g modes missing. Over the whole temperature range the frequency shifts are negligible whereas the line widths show a strong increase with temperature. Both reversible and irreversible line width behaviour are exhibited for different temperature runs, indicating a complex microscopic phenomenon underlying the creation of defects responsible for these line widths and their interaction with the different phonon modes. An approximate activation energy for defect creation of ΔE ≈︁ 0.3 eV can be obtained from the temperature behaviour of the line widths. This activation energy may be connected with the high‐temperature ionic conduction mentioned previously for this crystal.
Raman and infrared spectra of NH4H2(IO3)3 and KH2(IO3)3
Authors: Santha N. , Isaac M. , Nayar V. U. , Keresztury G. 
Published: May 2005

AbstractRaman and infrared spectra of NH4H2(IO3)3 and KH2(IO3)3 were recorded and analysed. The observed splittings of the stretching modes of IO3− are due to the distortion of the IO6 octahedra. In NH4H2(IO3)3, the ammonium ion can rotate freely and the NH4+ group forms only weak hydrogen bonds with the oxygen atom. Owing to Fermi resonance, three stretching bands are observed for the OH vibration in both compounds. The hydrogen bonds are slightly shorter in KH2(IO3)3 than in NH4H2(IO3)3.
Raman and IR spectra of β‐alanine and sarcosine monophosphates
Authors: Joe I. Hubert , Philip Daizy , Aruldhas G. , Botto I. L. 
Published: May 2005

AbstractThe IR and Raman spectra of the monophosphates of β‐alanine and sarcosine were recorded and analysed. The carboxylic group is found to exist as COO− and the orthophosphate as H3PO4 in β‐alanine monophosphate. In sarcosine monophosphate these groups seem to exist as COOH and H2PO4−, respectively.
Resonance Raman spectral studies on the vibrational frequencies of some azo dyes in the solid state and in alkaline solution
Authors: Chattopadhyay S. , Kastha G. S. , Brahma S. K. 
Published: May 2005

AbstractResonance Raman spectra of two azo dyes, 2‐hydroxy‐2′‐carboxy‐5‐methylazobenzene and 2‐hdroxy‐2′‐carboxy‐5‐methoxyazobenzene, in the solid state and in 0.1 M NaOH solution were investigated. For comparison, their infrared absorption spectra were also recorded in the solid state and in solution in chloroform. Characterization of the Bands in the Raman spectra of the alkaline solution and their assignments to different hybridized modes were made on the basis of the deprotonated azo and quinonoid molecular forms (in resonance) in alkaline solution.
CARS vibration‐rotation Q‐branch spectrum of hydrogen chloride
Authors: Edwards H. G. M. , Greenhalgh D. A. , Long D. A. , Sherwood G. 
Published: May 2005

AbstractThe self‐broadening of the Q‐branch vibration‐rotational lines in the CARS spectrum of HCl was studied over the pressure range 0.002‐1.000 bar and the temperature range 298‐1048 K. The broadening coefficients, σp, are dependent on J at 298 and 550 K but are independent of J at higher temperatures; the σp value of 1048 K is only about 25% of its value for Jmax at 298 K.
Near‐infrared fiber‐optic sample cell: Applications to fourier transform Raman and near‐infrared absorption and reflectance spectroscopies
Authors: Lewis E. Neil , Kalasinsky V. F. , Levin Ira W. 
Published: May 2005

AbstractA fiber‐optic sample cell designed for use in the near‐infrared region is described. For Fourier transform (FT) Raman spectroscopy, Nd:YAG laser radiation is transmitted to the sample through one fiber bundle, while a second fiber bundle collects and transfers the scattered light to the source compartment of an infrared interferometer equipped with a CaF2 beam splitter and an InGaAs detector. Because the two fiber bundles are mounted in the aluminum body of the cell, virtually no optical alignment is required. In addition to its utility in FT‐Raman spectroscopy, the cell may be used for obtaining near‐infrared absorption spectra of liquids and reflectance spectra of solids without changing its configuration. Examples of the many uses of the cell are provided, and modifications which would potentially improve its efficiency and expand its capabilities are discussed.
Raman spectroscopy at the University of São Paulo: Past, present and perspectives
Authors: Santos P. S. 
Published: May 2005

AbstractWe (J. R. Durig and T. S. Little, Department of Chemistry, University of South Carolina, Columbia, SC, USA) recently had an opportunity to visit the Molecular Spectroscopy Laboratory housed in the Institute of Chemistry at the University of São Paulo. This laboratory, directed and maintained by Professor O. Sala, is steeped in the history of Raman spectroscopy. The presence of the original Raman spectrograph, hand tooled by Professor Hans Stammreich in the 1940s, with the helium lamps still intact and located near the most modern of Raman equipment, created an unforgettable air of nostalgia. We kindly requested one of Professor Sala's close co‐workers (P. S. Santos) to provide the present article on the historical perspectives and significance of Raman spectroscopy at the University of São Paulo. We are pleased to present this overview to the readership of the Journal of Raman Spectroscopy.
Polarized Raman spectra of KIO4 and RbIO4 and high‐pressure Raman studies on KIO4
Authors: Al Dhahir T. A. , Bhat H. L. , Narayanan P. S. , Jayaraman A. 
Published: May 2005

AbstractPolarized Raman spectra of single crystals of KIO4 and RbIO4 were obtained. The observed fundamental modes satisfy the selection rules valid for the scheelite structure. The pressure dependence of the Raman spectra of KIO4, which was investigated up to 12 Gpa, reveals a structural phase transition in the crystal near 6.5 GPa, where new peaks are observed. Above 9.8 GPa only the peaks belonging to the high‐pressure phase exist.
Fourier transform Raman spectroscopy of superconducting YBa2Cu3O7‐δ films on strontium titanate and magnesium oxide substrates
Authors: Bist H. D. , Datta T. , Little T. S. , Thigpen J. C. , Durig J. R. , Broussard P. R. , Berkley D. D. 
Published: May 2005

AbstractThin sputtered films of the high‐Tc material YBa2Cu3O7‐Δ were investigated using 180° back‐scattering geometry with Fourier transform (FT) Raman spectroscopy. It is established that the main bands in the spectra of a YBa2Cu3O7‐Δ film on strontium titanate substrate exhibit similarity with those obtained for oriented untwinned crystallites of the superconductor having their c‐axis perpendicular to the surface of the substrate. No degradation or excessive heating of the film was observed with 1.064 μm excitation for low laser powers. The film on a magnesium oxide substrate gives unique evidence of the isolated strong, featureless, almost flat continuum, producing a broad maximum near the region of the antiphase axial bending O(2)Cu(2)O(3) motions of planar oxygens at very low excitation energy. This appears to be the first application of FT‐Raman spectroscopy using near‐infrared excitation (1.064 μm) to the field of high‐temperature superconducting films and their detailed characterization.
Raman spectroscopic determination of the dissociation constants of an acetonitrile–zinc complex in aqueous solution and the enthalpy and entropy of complex dissociation
Authors: Edwards H. G. M. , Hoskins A. R. , Johnson A. F. , Lewis I. R. 
Published: May 2005

AbstractThe dissociation constants for an acetonitrile‐zinc complex, (CH3CN)Zn2+, were measured in aqueous solutions containing zinc salts (40‐80%, w/w) and acetonitrile by Raman spectroscopy. Quantitative measurements of the intensity of the free and complexed ν(CN) Raman bands at 2264 and 2320 cm−1, respectively, were used to determine the average enthalpy and entropy of the complex dissociation to free acetonitrile in the temperature range 293‐343 K for a 70% (w/w) solution of zinc chloride (0.052 mol) in an aqueous solution containing acetonitrile (0.024 mol); δH° and δS° values of 8.4 ± 0.5 kJ mol−1, respectively, were determined.
Conformational properties of carbonylsulphenyl compounds: Vibrational study of bis(chlorocarbonyl) disulphide, ClC(O)SSC(O)Cl
Authors: Ulic S. E. , Aymonino P. J. , Védova C. O. Della 
Published: May 2005

AbstractIR data for vapour, liquid and matrix‐isolated bis(chlorocarbonyl) disulphide and Raman data for the liquid were obtained. The observed features agree with the existence of one conformer with C2 symmetry in both the liquid and vapour phases. The 13C NMR spectrum was measured and the results were compared with those for related molecules. Some stretching force constants were derived for this conformer from semi‐empirical calculations.
Raman spectra of the permanganate ion in the solid state with excitation in the near infrared
Authors: Engert C. , Kiefer W. 
Published: May 2005

AbstractBy means of a conventional Raman spectrometer that had been carefully designed for near‐infrared Raman excitation, it was possible to record highly resolved Raman spectra of solid polycrystalline potassium and barium permanganate. The spectra of these deeply coloured materials are of high quality and comparable to those reported hitherto, obtained using Fourier transform Raman techniques and near‐infrared excitation. Full site symmetry splitting and partial factor group splitting of the bands of the permanganate ion could be observed.
Surface‐enhanced resonance Raman scattering study on the hemicyanine dye 4‐ [2‐(4‐dimethylaminophenyl)ethenyl]‐1‐methylpyridinium iodide adsorbed on a silver electrode surface
Authors: Shibasaki Koichi , Itoh Koichi 
Published: May 2005

AbstractSurface‐enhanced resonance Raman scattering (SERRS) spectra were measured at O V (vs Ag/AgCl) for a hemicyanine dye and its protonated form (HC and HCH+) adsorbed on a silver electrode surface. The surface spectrum of HC shows a characteristic feature due to a trans conformation, a band mainly due to a stretching frequency (νcc) at 1580 cm−1, which is appreciably lower than the corresponding frequency for HC in water (1592 cm−1); this result indicates that, on adsorption on the electrode surface, the resonance balance of HC between the quinoid and benzenoid forms shifts to the former. An adsorbate on a silver electrode surface from HCH+ solution at pH 1.0 takes either a protonated form, HCH+, or a deprotonated form, HC, depending on the anodization conditions of granular structures assumes the deprotonated form, whereas the adsorbate on a surface containing smooth parts retains the protonated form; hence the surface morphology is related to the chemical properties of the silver electrode surfaces. It was also found that the adsorbate in the protonated state gives a prominent SERRS band at 885 cm−1 assignable to an out‐of plane bending vibration of the central olefinic group, indicating that the adsorbate assumes a flat orientation on the silver electrode surface.
Molecular recognition using surface‐enhanced Raman scattering from citrate‐reduced silver colloids in non‐aqueous solvents
Authors: Clarkson J. , Campbell C. , Rospendowski B. N. , Smith W. E. 
Published: May 2005

AbstractSurface‐enhanced Raman scattering (SERS) from citrate‐coated colloidal particles suspended in organic solvents is used to study surface reactions in an organic phase. Stable colloids which gave good SERS were produced from ethanol and acetonitrile. SERS was easily discriminated from the bulk solvent Raman scattering. Compounds which are sparingly soluble in water including 2,2′‐bipyridine and benzene‐1,2,4,5‐tetracarboxylic acid dianhydride produced good SERS in ethanol. In the latter case, no SERS was observed from an aqueous colloid. Therefore, some form of solvent‐dependent molecular recognition may operate. The formation of a bipyridine complex with copper(II) at the surface in a solvent system in which the ligand and complex are both soluble was observed. The solvent altered surface reactions. In the ethanol colloid, in contrast to the result in aqueous colloid, pyridine does not replace citrate readily. This work demonstrates the potential for the expansion of the use of colloidal SERS into the field of surface reactions in contact with an organic phase and is related to metal liquid‐like films.
Vibrational modes of CO adsorbed on disordered copper films
Authors: Akemann W. , Otto A. 
Published: May 2005

AbstractThe Raman spectrum of CO adsorbed on copper films featuring atomic‐scale roughness reveals four vibrational modes: a CO stretching mode at 2102 cm−1, a restricted rotation at 282 cm−1 and restricted translations normal and parallel to the local surface at 355 and 24 cm−1. The spectrum originates from a minority of CO molecules adsorbed at surface defect sites via a single coordination bond. The bond strength is increased compared with adsorption at facet sites, presumably owing to increased σ‐donation promoted by a local depletion of conduction electron density. A splitting of the translational mode into two separate frequencies, expected for adsorption sites with rotational symmetry less than C3v, is not observed. The intensities and line shapes of the SERS bands are sensitive to a thermally induced rearrangement of the molecules within the adsorbate layer. Spectra from annealed substrate films indicate dominant excitation of the rotational mode on surfaces with a lesser degree of atomic‐scale roughness. This is explained by the relevance of Herzberg‐Teller contributions to the inelastic scattering of photoexcited electrons by the surface molecules.
Surface‐enhanced Raman spectroscopy of silver etched by CrO3H2SO4: Study of adsorbed sulphate
Authors: Pagannone M. , Quagliano L. G. , Mattioli L. , Mattei G. 
Published: May 2005

AbstractThe surface‐enhanced Raman (SER) spectra of sulphate adsorbed on silver were obtained by treating it with a sulphochromic mixture, CrO3H2SO4. When nitrate or pyridine are added to the etching solution, there is evidence that both species can co‐adsorb with sulphate. The analysis of SER bands obtained under different conditions indicates that in some cases sulphate is perhaps physically adsorbed on the surface, preserving its free ion Td symmetry, whereas in others it is chemisorbed, presumably in the form of a bidentate complex having C2ν symmetry. The antisymmetric stretching vibrational mode ν3 of sulphate is very sensitive to the presence of species co‐adsorbed on the surface.