bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature and pressure dependence of the ν1 band of water vapour by high‐resolution inverse Raman spectroscopy
Authors: Greenhalgh D. A. , Rahn L. A. 
Published: May 2005

AbstractThe Raman spectrum of the ν1 band of water vapour at pressures up to 300 τ and for five temperatures between 300 and 1200 K was measured using high‐resolution inverse Raman spectroscopy. Self‐broadening coefficients were determined for 59 distinct lines from J = 0 to J = 11. The temperature dependence of these coefficients was also determined for most of these lines and was compared with previously published calculations. Spectral regions where deviations have been previously observed between measured and calculated CARS spectra of the ν1 band were studied in detail. Corrections to line positions and relative intensities are suggested for improving the current water vapour spectral model.
Raman and IR spectra of Te(OH)6·2Na3P3O9·6H2O
Authors: Philip Daizy , Aruldhas G. , Mathew Xavier , Nayar V. U. , Boudjada N. , Lambert‐Andron B. 
Published: May 2005

AbstractRaman and IR spectra of Te(OH)6·2Na3P3O9·6H2O were recorded and analysed. The vibrational bands due to P3O, TeO6 octahedra and water molecules were identified. It was found that P3O has a ring structure in the compound. The TeO6 group and P3O were found to coexist independently in the crystal. Further, the water molecules are non‐equivalent in the unit cell.
Raman spectroscopic study of hexacarbonyl molybdenum(0) entrapped in zeolite cages
Authors: Brémard C. , Grousilliers H. Des 
Published: May 2005

AbstractRaman scattering studies of entrapped Mo(CO)6 in faujasite‐type zeolite cages, as a function of zeolite type and temperature, evidence the intracavity electrostatic field effect and the intermolecular interactions within the zeolite framework.
Continuum resonance Raman scattering in bromine: Comparison of time‐dependent calculations with time‐independent and experimental results
Authors: Hartke Bernd 
Published: May 2005

AbstractAn application of time‐dependent theory to continuum resonance Raman scattering in 79Br2 is described. Calculated profiles and spectra are compared with traditional time‐independent results and experimental spectra from the literature. Similarities and differences between the time‐dependent and time‐independent methods from their theoretical derivation through different stages of results up to their explanatory power are evaluated.
Description and performance of a highly sensitive confocal Raman microspectrometer
Authors: Puppels G. J. , Colier W. , Olminkhof J. H. F. , Otto C. , de Mul F. F. M. , Greve J. 
Published: May 2005

AbstractA confocal Raman microspectrometer was developed for the study of small biological objects such as single living cells and metaphase and polytene chromosomes. It employs a confocal detection scheme, well known from confocal fluorescence microscopes, in order to avoid signal contributions from the environment of the samples. The resolution is 0.45 ± 0.05 μm in the lateral direction and 1.3 ± 0.1 μm in the axial direction. The laser excitation wavelength is 660 nm. At this wavelength biological samples do not degrade in the laser radiation as was the case when laser radiation of 514.5 nm was used. The signal throughput from the sample position to the detector was optimized to the extent that in the spectral region around a 1000 cm−1 Raman shift 15% of the Raman scattered light collected by the microscope objective is detected. For signal detection a liquid nitrogen‐cooled slow‐scan CCD camera is used. Laser powers of 5–10 mW suffice to obtain high‐quality Raman spectra, with signal integration times of the order of minutes. As an example, spectra obtained from the nucleus and the cytoplasm of an intact human lymphocyte are shown.
Raman and infrared spectra of the solid chlorofluorocarbons. III–trichlorofluoromethane
Authors: LeBlanc L. M. , Anderson A. 
Published: May 2005

AbstractRaman and infrared spectra of crystalline trichlorofluoromethane at temperatures between 20 and 80 K were recorded in both the lattice and internal mode regions. The lattice spectra are shown to be compatible with a non‐centrosymmetric tetragonal unit cell containing four molecules on mirror plane sites, and plausible assignments are proposed. The internal mode splittings are interpreted in terms of isotopic, crystal field, Fermi resonance and LO‐TO effects.
Resonance Raman studies of the mechanism of photoreduction of iron protoporphyrin‐IX dimethyl ester in the presence of axial ligands
Authors: Verma A. L. , Chaudhury N. K. 
Published: May 2005

AbstractResonance Raman studies of iron protoporphyrin‐IX dimethyl ester chloride [FeIII(PPDME)Cl] in the presence of biologically relevant axial ligands such as 2‐methylimidazole (2‐MeIm) and 1,2‐dimethylimidazole (1,2‐Me2Im) revealed the occurrence of photoreduction even under aerobic conditions by excitation near the Soret absorption band. A comparison of the vibrational modes sensitive to the oxidation, spin and coordination states of the photoreduced and chemically reduced forms of FeIII(PPDME)Cl confirmed that the reduction of the central iron atom in the high‐spin state takes place without any reduction of the porphyrin ring. No photoreduction is observed in pure dichloromethane solvent but trace amounts of alcohols and also some other polar solvents, which facilitate the separation of ion pairs, catalyse the process of photoreduction. From the exponential dependence of the fraction of sample reduced on the rate of photoreduction and illumination time, the rate constant for photoreduction, k−1R = 10 min, is obtained and the action spectrum of photoreduction shows a maximum coinciding with the Soret absorption band. The electron transfer from the axially ligated 2‐MeIm to iron appears to be a primary step in photoreduction. From the dependence of photoreduction on the concentration of 2‐MeIm, the ligand‐free, intermediate spin FeII (PPDME) was identified as the intermediate species formed during photoreduction.
Raman spectrum of [MgCl(THF)5] [FeCl4] · THF
Authors: Shamir Jacob , Sobota Piotr 
Published: May 2005

AbstractThe Raman spectrum of [MgCl(THF)5] [FeCl4] · THF includes all four Raman‐activ vibrations of the [FeCl4]− anion, thus supporting the results obtained by x‐ray analysis. On the other hand, no vibration which could be assigned to the MgCl bond has been observed, which may indicate that this bond is more likely to be ionic.
Raman microprobe spectroscopy of icing on metal surfaces
Authors: Sonwalkar Nishikant , Sunder S. Shyam , Sharma S. K. 
Published: May 2005

AbstractA simple optical low‐temperature icing cell was fabricated to obtain the in situ Raman spectra of ice layers forming on metallic substrates. The icing cell is optically coupled to a micro Raman multi‐channel spectrometer. The Raman spectra of the initial ice layers show characteristics of a disordered phase resembling low‐density amorphous ice. The crystalline phase develops gradually as the thickness of the ice layer increases. The disorder in the initial ice layer may be caused primarily by the rapid thermal cooling, and appears to be independent of the type of metal substrate.
Determination of excited state potential functions from continuum resonance Raman scattering: Excitation of 79Br2 from the visible to the UV region
Authors: Strempel J. , Kiefer W. 
Published: May 2005

AbstractHigh‐resolution polarized and depolarized resonance Raman spectra of isotopically pure molecular bromine (79Br2) with Δν = 1–5 were recorded using the argon laser lines at 501.7, 496.5, 488.0, 476.5, 457.9, 363.8, 351.1 and 333.6 nm and the Kr laser line 413.1 nm. Using a high‐sensitive CCD camera, the experimentally obtained spectra have better signal‐to‐noise ratios than some of the spectra already published. All observed spectra were also calculated using second‐order perturbation theory. The high sensitivity of resonance Raman band shapes to changes in the position of excited potential curves gives the possibility of determining the potential functions of the excited states 1II1u and 3II0+u in the energy range between 20 000 and 30 000 cm−1 very accurately. These potentials allow a satisfactory description of all observed spectra, including those of the overtones, in contrast to earlier work.
Vibrational study on ferroelectric dipoles in rochelle salt
Authors: Kanesaka Isao , Kita Hayato 
Published: May 2005

AbstractComplete polarized Raman spectra in the region of OD stretchings in a partially deuterated Rochelle salt were observed at room temperature and 77 K. The spectra were analysed by comparison with calculated intensity variations, identifying some bands definitely and deducing a ferroelectric dipole with a two‐site structure, where the OD stretchings are 2520 and 2424 cm−1 at room temperature. The infrared spectra in the region of OD stretchings and also OH decoupled stretchings were observed in the temperature range 310‐20 K. One of two components in the ferroelectric dipole at 2507 cm−1 was observed even at 20 K, indicating a small energy difference between the two sites. On the other hand, no important spectral change at 2507 cm−1 was found on passing through the ferroelectric phase transition. An OH group with a two‐site structure with an energy difference of 2.4 kJ mol−1 was observed for the first time at 3536 and 3523 cm−1 at 240 K, although the corresponding OD stretching was not split. It is considered that this group is not responsible for ferroelectricity.
Barrier to asymmetric internal rotation, conformational stability, vibrational spectra and assignments, and Ab Initio calculations of n‐butane‐d0, d5 and d10
Authors: Durig J. R. , Wang Aiying , Beshir Wafaa , Little T. S. 
Published: May 2005

AbstractThe asymmetric torsional potential function of n‐butane has been redefined based on a combination of results obtained from experimental and theoretical calculations. From the vibrational spectra of gaseous n‐butane below 500 cm−1 the asymmetric torsional fundamentals of the more stable s‐trans and high‐energy gauche conformations of n‐butane have been assigned at 121.28 and 116.60 cm−1, respectively, each with excited states falling to lower frequencies. Additionally, from variable‐temperature studies of the Raman spectra for n‐butane‐d0 and d10, the conformational enthalpy difference has been determined to be 381 ± 41 cm−1 (1089 ± 117 cal mol−1) and 369 ± 72 cm−1 (1055 ± 206 cal mol−1), respectively. Optimized structural parameters, obtained from ab initio methods, for the s‐trans and gauche conformers have been used to allow for structural relaxation during the asymmetric internal rotation and to place constraints on the determined potential function. The resulting potential coefficients are V1 = 584 ± 7, V2 = ‐96 ± 7, V3 = 1165 ± 3, V4 = 45 ± 3, V5 = ‐3 ± 2 and V6 = ‐40 + 1 and the s‐trans to gauche, gauche to gauche and gauche to s‐trans barriers are determined to be 1274, 1370 and 891 cm−1, respectively, with an enthalpy difference between the conformers of 383 ± 17 cm−1 (1095 ± 49 cal mol−1). This potential function is consistent with a dihedral angle for the gauche conformer of 65.4°. Additionally, this potential has a ‘syn’ barrier, which is the energy difference between the s‐trans minimum and the gauche to gauche transition state, of 1753 cm−1 (5.01 kcal mol−1), which is in excellent agreement with the most recent value of 1836 cm−1 (5.25 kcal mol−1) obtained from a very high‐level ab initio calculation. In order to provide a more complete description of the normal vibrational modes of n‐butane, normal coordinate analyses have been completed for n‐butane‐d0, ‐d5 and ‐d10 based on force constants from ab initio calculations. The infrared (3500‐40 cm−1) and Raman (3500‐10 cm−1) spectra of n‐butane‐d5 and ‐d10 have been obtained and complete vibrational assignments are provided. The structural parameters, conformational stabilities, barriers to internal rotation and vibrational frequencies which have been determined experientally are compared with those obtained by ab initio methods.
Surface‐enhanced Raman scattering of adsorbates
Authors: Otto A. 
Published: May 2005

AbstractThis review concentrates on the electronic contribution to surface‐enhanced Raman scattering (SERS). This socalled ‘chemical effect’ is quantitatively separated from classical electromagnetic enhancement. It proceeds by increased electron‐photon coupling at an atomically rough surface and by temporary charge transfer to adsorbate orbitals. These concepts are supported by various experimental results. The model accounts for the chemical specificity and vibrational selectivity of SERS and (partly) for the ‘SERS specificity’ of various metals.
High‐sensitivity Raman spectroscopic study on surface‐pressure dependence of the structure in thin langmuir–blodgett films of dipalmitoylphosphatidylcholine
Authors: Okamura Emiko , Umemura Junzo , Takenaka Tohru 
Published: May 2005

AbstractBy combining a high‐sensitivity charge‐coupled device detector with the total reflection technique, Raman spectra in the CH stretching region were recorded for thin Langmuir‐Blodgett (LB) films of dipalmitoylphosphatidylcholine (DPPC) prepared at various surface pressures encompassing the plateau region of its surface pressure‐area isotherm. Surface‐pressure dependences of the lateral packing and the conformational order are discussed using the peak intensity ratio between the 2880 and 2850 cm−1 bands and that between the 2935 and 2850 cm−1 bands. The results indicate that at higher surface pressures above the plateau, the hydrocarbon chains of DPPC are tightly packed and highly oriented with the all‐trans conformation. Below the plateau, however, the chains are disordered because of the increased number of the gauche conformers. The loosely packed hydrocarbon chains observed for the LB films deposited at lower surface pressures are gradually reoriented with time to form stable and highly ordered aggregates.
Surface‐enhanced Raman scattering of the complexes of silver with adenine and dAMP
Authors: Otto C. , Hoeben F. P. , Greve J. 
Published: May 2005

AbstractThe behaviour of adenine and 2′‐deoxyadenosine‐5′‐monophosphate (dAMP) at positive surface potentials of a silver working electrode was investigated using surface‐enhanced Raman scattering (SERS). The use of positive potentials in the presence of adenine or dAMP leads to a rapid accumulation of an intense spectrum. It is proposed that complexes of adenine (dAMP) with silver generate the observed spectra. Adenine and dAMP can be distinguished spectroscopically due to various different complexes that can be formed for adenine and not for dAMP. The SERS spectra of the silver‐adenine complexes show broad, unresolved bands between 1200 and 1500 cm−1, while the spectra of complexes of silver with dAMP show clearly resolved bands. The formation of Ag+‐adenine complexes gives rise to a decrease in pH and must therefore be associated with deprotonation of the adenine ring system. The SERS spectra of adenine can be obtained in solutions with a pH of 3.0, 7.5 and 11.0 whereas the SERS spectra of dAMP can only be obtained at a pH of 7.5 and 11.0. The time dependence of the SERS spectra of dAMP suggests that at least two different complexes of silver with dAMP are involved. The observed spectra are completely different from the ‘classical’ SERS spectrum of adenine and dAMP. This spectrum is characterized by an intense band at 729 cm−1 (at –700 mV vs. SCE). At open loop potential, however, the spectra of the Ag‐dAMP complex change slowly to the ‘classical’ SERS spectrum of dAMP.
Resonance Raman and far‐infrared studies of n‐Bu4NI3 and n‐Bu4NBr3
Authors: Zambounis J. S. , Kamitsos E. I. , Patsis A. P. , Papavassiliou G. C. 
Published: May 2005

AbstractThe resonance Raman and far‐infrared spectra of n‐Bu4NI3 show the coexistence of symmetrical (C2ν) and unsymmetrical (Cs) I3 − species, which are clearly distinguished by varying the wavelength of the excitation line. Only a slight deviation from D∞h symmetry has been deduced for the Br3 − ions in n‐Bu4NB3.
Resonance CARS spectroscopy on diacetylene single crystals
Authors: Materny A. , Leuchs M. , Michelis T. , Schaschek K. , Kiefer W. 
Published: May 2005

AbstractAn experimental CARS set‐up for resonant solid‐state coherent spectroscopy is described. Resonance CARS spectra of one unsymmetrically (TS/FBS) and two symmetrically (TS6, FBS) substituted diacetylene monomer single crystals, with a low content of polymer, were obtained with this apparatus. Particularly, spectra of the CC and the CC stretching vibrations of the polymer chains, recorded for different pump laser frequencies, were investigated. The occurrence of broad spectral CARS features which are non‐resonant and Stokes shifted relative to other observed CARS lines is discussed.
Polarized Raman spectra of single‐crystal barium nitroprusside trihydrate, Ba[Fe(CN)5NO]·3H2O
Authors: Güida J. A. , Piro O. E. , Aymonino P. J. , Sala O. 
Published: May 2005

AbstractThe room‐temperature polarized Raman scattering of single‐crystal Ba [Fe(CN)5NO] · 3H2O, space group Pbcm (D, No. 57), in the 2200–10 cm−1 spectral range, and a factor group analysis of the nitroprusside anion vibrational modes are presented. The near parallelism between the anion NCFeNO axis and a crystallographic axis facilitates the interpretation of the spectra. The data obtained complement already existing IR studies and the two series of results together provide reference information for the understanding of the vibrational behaviour of the recently reported electronically excited metastable states of the anion. The Raman data confirm the existence of a relatively large correlation (Davydov) splitting between NO stretching modes due to vibrational coupling between neighbouring nitrosyl groups in the lattice.
Fourier transform Raman spectrum of polycrystalline pyrazole, vibrational assignment and ab initio calculations
Authors: Durig J. R. , Bergana M. Mamula , Zunic W. M. 
Published: May 2005

AbstractThe Fourier transform Raman spectrum from 100 to 3300 cm−1 of liquid and polycrystalline pyrazole, magnified image was recorded. The frequencies for several of the fundamentals are significantly different from those obtained from the Raman spectra of solutions. The data are interpreted in detail. The previous assignment of one of the out‐of‐plane fundamentals (A") for the isolated molecule is questiond. The structural parameters, fundamental vibrational frequencies and values for the force constant were obtained from ab initio Hartree–Fock gradient calculations utilizing the 3–21G basis set. These results are compared with the values of some of these physical quantities previously reported.
Raman and far‐infrared spectra of cyanamide at 20 and 90 K: Atom‐atom potentials and lattice frequencies
Authors: Torrie B. H. 
Published: May 2005

AbstractThe Raman and infrared spectra of cyanamide have been remeasured at lower temperatures (20 K) and higher laser powers (for the Raman). The recently obtained structure of cyanamide was used as a basis for calculations of the lattice dynamics. Standard models using atom‐atom potentials of the exp ‐ 6 form, an exponentially decaying attractive potential for the hydrogen bond and distributed dipoles on the atoms, gave good fits to the structural parameters and, with scaling, gave moderately good values for the lattice frequencies provided that it was assumed that the modes associated with librations about the long axis of the molecule were not observed.
Infrared, Raman and pre‐resonance Raman spectra of vanadyl(IV) tetraphenylporphyrin
Authors: Baran E. J. , Jubert A. H. , Ferrer E. G. 
Published: May 2005

AbstractThe infrared and Raman spectra of vanadyl(IV) tetraphenylporphyrin were recorded between 1600 and 200 cm−1. Assignment of most of the vibrational modes was done by comparison with other related compounds. The VN and VO metal—ligand vibrations could be clearly identified. Pre‐resonance experiments were performed, using different radiation from an argon ion laser, in the energy range between the main electronic transitions of the complex [the Soret band and the (α + β) doublet]. Analysis of the excitation profiles suggests that all the enhanced bands contribute to both the A and B terms of Albrecht's equation.
Analyse Vibrationnelle des Acides gem‐Dimethylglutarique en Solution Aqueuse. I—Acide 2,2‐Dimethylglutarique et Ses Sels de Potassium
Authors: Yolou S. , Delarbre J. L. , Maury L. 
Published: May 2005

AbstractLes spectres Ramon et infrarouge de l'acide 2,2‐diméthylglutarique et de ses sels de potassium ont été analysés. Les résultats obtenus nous permettent de proposer une attribution des modes fondamentaux et de déterminer le groupe de symétrie de chaque ion ou molécule.
IR and Raman spectra of AgNO3 at low temperatures
Authors: Shen Z. X. , Sherman W. F. , Kuok M. H. , Tang S. H. 
Published: May 2005

AbstractThe IR spectra of AgNO3 were recorded using single‐crystal samples and polarized radiation. More detailed information was obtained than that reported in previous studies using polycrystalline samples. The very strong IR absorption bands of the ν3 and ν2 modes were studied by polarized reflection measurements. Raman spectra of AgNO3 were also recorded and used to provide supplementary data. Better assignments for the components of the fundamental modes were obtained using the polarized spectra, and some isotope and combination bands were also observed and assigned. The present data allow a better understanding of the splittings of the fundamental modes. The low‐temperature phase showed a softening of the ν3 and ν4 modes as the crystals were cooled below the transition temperature (140 K), and this suggests a limited (P, T) range of stability for this phase.
Vibrational study on phase transition in ammonium Rochelle salt
Authors: Kanesaka Isao , Kita Hayato 
Published: May 2005

AbstractPolarized Raman spectra of partially deuterated ammonium Rochelle salt in the region of O—D stretchings were observed at room temperature. The O—D stretchings were assigned by reference to intensity variations in polarized spectra. The O—D stretchings and also the decoupled N—D stretchings in the infrared spectrum split into many bands below Tc. Some bands split abruptly and others gradually. The abrupt splitting is ascribed to a displacive structural change of water molecules in relation to tartrate ions which accompanies ordering at one of two NX4 + sites (X = H or D). The gradual splitting is ascribed to gradual freezing of reorientational motions at the other NX4 + site. The mechanism of the phase transition is discussed in terms of these structural changes.
Resonance Raman spectra of tris(violurate)ruthenium(II) and of mixed (violurate)bis(2,2′‐bipyridine)ruthenium(II) complexes
Authors: Constantino V. R. L. , Toma H. E. , de Oliveira L. F. C. , Santos P. S. 
Published: May 2005

AbstractThe existence of two independent chromophores in [Ru(bipy)2(H2V)]+, where H2V− = violurate anion and bipy = 2,2′bipyridine, was demonstrated by comparing its resonance Raman spectra with those displayed by the [Ru(H2V)3]− analogue. In the former, the electronic band at 478 nm was assigned to the Ru → H2V MLCT transition, whereas the band at 415 nm was assigned to the Ru → bipy MLCT transition. In both species a tentative assignment is proposed for the enhanced modes based on comparison with related examples from the literature.