bluuebunny/crossref_metadata_2025_split huggingface dataset:
The hyper‐Raman effect in molecular gases
Authors: Altmann K. , Strey G. 
Published: May 2005

AbstractThe theory of the hyper‐Raman effect in molecular gases is reviewed. In order to calculate relative intensities of vibration‐rotation lines in hyper‐Raman spectra, line strengths are introduced and these are calculated using the method of irreducible spherical tensors. It transpires that the hyper‐Raman effect caused by scattering of a quasi‐monochromatic light beam can be fully described by five independent line strength expressions. Rotational and vibrational selection rules as well as depolarization ratios for linearly, circularly and naturally polarized incident light are derived and discussed. The angular dependence of the scattered intensity is also given in the form of polar diagrams. To some extent the paper presented here parallels that published by Placzek and Teller54 in 1933 on the rotational structure of vibrational bands in conventional Raman spectra caused by a spontaneous two‐photon scattering process.
Resonance Raman spectra of 9,9′‐bifluorenylidene
Authors: Angeloni L. , Panerai S. , Sbrana G. 
Published: May 2005

AbstractThe resonance Raman spectra of 9,9′‐bifluorenylidene have been measured in the 450–510 nm region either in solution or in the solid state by using six lines of the Ar+ laser. The analysis of the excitation profiles allowed inferences to be drawn concerning the vibronic structure of the lowest electronic excited state. The different behaviour shown by the profiles relative to the solid and the solution has been interpreted as due to different Franck‐Condon overlap integrals between the ground and the excited electronic states. A vibrational assignment of the g modes is proposed on the basis of a polarized Raman spectrum in solution taken with the 632.8 nm line of a He‐Ne laser. Electronic spectra of NaCl pellets and of oriented polycrystalline samples were also measured.
Vibrational spectra and conformations of (bromomethyl)cyclopropane and epibromohydrin
Authors: Wurrey C. J. , Krishnamoorthi R. , Pechsiri S. , Kalasinsky V. F. 
Published: May 2005

AbstractInfrared and Raman spectra of (bromomethyl)cyclopropane and epibromohydrin have been recorded. Reversible spectral changes which accompany changes in temperature indicate the existence of an equilibrium mixture of gauche and cis conformers for (bromomethyl)cyclopropane. The gauche form is more stable, and from the variable temperature studies an enthalpy difference of 2.0±0.2 kcal mol−1 has been obtained for the liquid phase. For epibromohydrin, two non‐equivalent gauche conformers have been identified, and the gauche‐1 form is more stable than the gauche‐2 by 0.80±0.20 kcal mol−1 in the liquid phase. Additionally there is evidence for a third conformer, presumably the cis form, but characterization of this conformer has been limited by the complexity of the spectra associated with the gauche‐1 and gauche‐2 forms. Consequently, only a lower limit can be given for the ΔH separating the cis and gauche‐1 conformers. The results are consistent with previous observations for similar molecules.
Raman spectra of mercury (II) chloride in aqueous solutions of strong acids
Authors: Waters D. N. , Kantarci Z. 
Published: May 2005

AbstractThe frequency of the symmetric stretching vibration ν5 of HgCl2 in aqueous solutions of HClO4 or HNO3 shows a strong dependence on acid concentration. This is attributed primarily to a weakening of oxygen‐tomercury electron pair donation as the acid concentration increases, although, for HNO3 solutions at high concentrations, the formation of nitrato‐complexes might also be implicated.
Effects of membrane bilayer reorganizations on the 2103 cm−1 Raman spectral CD stretching mode linewidths in dimyristoyl phosphatidylcholine‐d54 (DMPC‐d54) liposomes
Authors: Bryant Gail J. , Lavialle Francoise , Levin Ira W. 
Published: May 2005

AbstractThe sensitivity of the bandwidths of the 2103 cm−1 symmetric methylene CD2 stretching modes to lateral chain‐chain interactions and to intrachain rotamer formation is demonstrated for membrane bilayer systems composed of deuterated phospholipids. Temperature profiles, constructed from three separate linewidth parameters, illustrate the effects of bilayer rearrangements both in pure DMPC‐d54 liposomes and in DMPC‐d54 multilayers containing melittin in a lipid:polypeptide mole ratio of 14:1. Evidence is presented for a class of immobilized deuterated boundary lipids surrounding the polypeptide.
Polarized Raman spectra of oriented monodomains of phospholipid multilayers
Authors: Peticolas W. L. , Harrand M. , Dupeyrat R. 
Published: May 2005

AbstractA method is described for preparing oriented monodomains of phospholipids multilayers from which polarized Raman spectra can be obtained. Typical polarized Raman spectra are shown and the band intensity changes are briefly discussed.
Deuteration kinetics of N‐methylacetamide by means of a stopped‐flow multi‐detector Raman spectrophotometry
Authors: Nishimura Yoshifumi , Tsuboi Masamichi 
Published: May 2005

AbstractN‐methylacetamide dissolved in 1H2O was rapidly mixed with 2H2O by the use of a stopped‐flow device, and Raman spectra of the mixed solution were observed at various times in the course of the deuteration reaction by the use of a multi‐detector system. With continuous wave excitation (Ar+ laser), the time‐resolution reached by our present setup was about 50 ms. The molecular association of N‐methylacetamide in H2O was found to cause a low‐frequency shift of the amide III Raman band at 1317 cm−1 by 9 cm−1. The effect of this association upon the deuteration rate, however, was not found to be appreciable. At 25°C, the rate constants were determined to be 0.067, 0.14, 0.20, 0.41, and 0.63 s−1 at pH = 6.43, 6.87, 7.15, 7.39, and 7.43, respectively.
Effet de la Temperature sur les Modes Externes de Vibration du Monocristal. La2(SO4)3·9(H,D)2O
Authors: Rull F. , Pastor J. M. , de Saja J. A. , Long D. A. 
Published: May 2005

AbstractThe polarized Raman spectra in the region 0–400 cm−1 of oriented single crystals of La2(SO4)3.9H2O and La2(SO4)3. 9D2O have been recorded between 14 and 297 K. The behaviour of the external modes is analysed in order to elucidate the role of the hydrogen‐bonds and the lanthanum‐oxygen interactions in the order‐disorder transition observed at approximately 170 K. Large changes in the shape and intensities of the external bands with temperature (not detected in the region of internal vibration of the spectrum) have been observed.
Resonance Raman spectra of reaction intermediates formed from 1,1‐ diphenylethylene adsorbed on porous vycor glass and on a catalyst
Authors: Yamamoto Yoichiro , Yamada Haruka 
Published: May 2005

AbstractResonance Raman spectra of three types of reaction intermediates, blue, green and yellow species, formed from 1,1‐diphenylethylene adsorbed on porous Vycor glass were measured by means of an improved experimental technique and with suitable excitations. The blue species, which is the least stable intermediate, is found to be a cation radical, , and the characteristic Raman bands of and 2 stretching vibrations are clearly observed. For the green and yellow species more detailed spectra were obtained than in previous experiments. The coverages of the three intermediates are θ≈︂10−3 for each, being in agreement with the values expected from the numbers of Lewis and Brönsted acid sites on porous Vycor glass. Resonance Raman spectrum of the blue species on silica‐alumina, a catalyst, was also obtained by using the rotating sample technique.
Temperature dependent width of γ(NH) mode in hydrogen bonded solid amides
Authors: Zerbi G. , Delleplane G. 
Published: May 2005

AbstractThe temperature dependence of νi, Δν and the integrated band area for a few solid amides are studied for the γ(NH) mode in the infra‐red. A general theoretical discussion of these structureless broad γ(NH) bands is presented. The bands are accounted for in terms of coupling of the γ(NH) mode with longitudinal as well as transversal low‐frequency phonons.
The effects of intermolecular potentials on the vibrational spectra of condensed systems
Authors: Fujiyama Tsunetake 
Published: May 2005

AbstractThe effects of the Intermolecular interaction potential on the vibrational spectra of liquids or solutions are discussed for the cases where the molecular field can be treated as a time or space‐averaged quantity. It is shown that the introduction of an appropriate molecular field can yield information about molecular properties or about molecular arrangements of component molecules in the liquid and solution phases. Certain spectral characteristics, for instance absorption intensity in infra‐red spectra and scattering cross‐section and depolarization ratio in Raman spectra, are discussed.
Improved rotational constants for fluorine 19F2 using coherent anti‐stokes Raman spectroscopy of the vibrational Q branch
Authors: Gilson T. R. , Purnell M. R. 
Published: May 2005

AbstractA coherent anti‐Stokes Raman spectroscopy spectrum of the resolved Q branch of the fundamental ν =0–1 vibration for fluorine, 19F2, has been obtained. The Q branch spectroscopic constants are found to be (‐αo) =−0.012972±0.00007 cm−1 and (±βo) = −(8±1)×10−8 cm−1. These are used to derive new values for the equilibrium and the ν = 1 rotational constants, and lead to an improved estimate for re = 1.41426±0.00004 Å.
Normal coordinate analysis of the Raman and infrared vibrations of the alpha phases of RE2O3 (RELa, Pr, Nd) and RE2O2S (RELa and Yb)
Authors: Gopinath C. R. , Brown I. D. 
Published: May 2005

AbstractA normal coordinate analysis of the spectra of the title compounds shows that they can be matched with a 6 force field. Metal‐O(S) force constants correlate approximately with bond length and range from 0.2 to 1.8 mdynes Å−1. OO(S) force constants are less than 0.1 mdynes Å−1 but for a satisfactory fit a metal‐metal force constant of 0.5 mdynes Å−1 must be introduced. The infrared spectrum of Pr2O3 is reported for the first time.
Raman excitation profiles of trans‐ azobenzene in the 361 to 494 nm wavelength range by means of a pulsed dye laser source
Authors: Houben Julien L. , Masetti Giorgio , Campani Enzo , Gorini Giampaolo 
Published: May 2005

AbstractSeveral Raman excitation profiles of trans‐ azobenzene in carbon tetrachloride have been obtained in the wavelength range 361–494 nm. By using 21 different exciting wavelengths from a tunable pulsed dye laser the eight most intense Ramanlines occurring in the 1000–1600 cm−1 shift range were investigated and the effective absorption wavelengths λeff were located. The results indicate that in the investigated range of exciting wavelengths a few molecular states corresponding to vibrational structures of the π*←π absorption band at 319 nm contribute predominantly to the Raman scattering from all analysed vibrational modes.
A Raman spectroscopic study of molecular interaction in long‐chain primary amines systems
Authors: da Costa A. M. Amorim , Geraldes C. F. G. C. , Teixeira‐Dias J. J. C. 
Published: May 2005

AbstractThe NH, CH and CC stretching regions at 3100‐3400 cm−1, 2800‐3000 cm−1 and 1000‐1150 cm−1, respectively, and the low‐frequency accordion‐like vibration region, have been investigated by Raman spectroscopy for the octyl‐, nonyl‐, dodecyl‐, tetradecyl‐ and hexadecyl‐normal primary amines series, at different temperatures and for different physical states. The spectra were interpreted in terms of structural changes, particularly of the conformations of the paraffin chains, the chain length and the physical state. The changes in the NH region were associated mainly with molecular association, whereas the changes in the other spectral regions studied were associated mainly with the molecular packing of the chains.
Free radical studies by resonance Raman spectroscopy. The 5,10‐dihydrophenazine and 5‐methyl‐10‐hydrophenazine radical cations
Authors: Hester Ronald E. , Williams Kenneth P. J. 
Published: May 2005

AbstractThe 5‐10‐dihydrophenazine and the 5‐methyl‐10‐hydrophenazine free radical cations have been prepared at room temperature by photolysis of phenazine and 10‐methylphenazine, respectively, in acidic ethanol solution. Both radicals exhibit very intense visible absorptions which have permitted the excitation of their resonance Raman spectra. Raman spectra have been recorded using various laser exciting lines, and excitation profiles for both systems have been determined. The parent‐to‐radical wavenumber shifts observed for each species have been interpreted in terms of the structural changes brought about by radical formation.
Low frequency depolarized light scattering in associated and non‐associated liquids
Authors: James David W. , Irmer Raimund 
Published: May 2005

AbstractA study of the low frequency depolarized spectra of liquid CCl4, C2Cl4, CH3OH and H2O has been undertaken using Raman spectroscopy. The spectra are not well described by dipole or, induced‐dipole models but a rotational diffusion model is satisfactory. The spectra were parametrized using two component bands (having Lorentzian and Lorentzian‐Gaussian product form) for the central Rayleigh peak and, for the associated liquids, one or more Gaussian bands of shifted frequency. The derived band parameters are rationalized in terms of the rotational diffusion model.
Influence of the solvent environment on the polarization properties of resonance Raman scattering in haemoglobin
Authors: Schweitzer R. , Dreybrodt W. , Mayer A. , el Naggar S. 
Published: May 2005

AbstractMeasurements of the depolarization ratio of the four resonant Raman lines at 1375 cm−1, 1506 cm−1, 1583 cm−1, and 1638 cm−1 were performed for all exciting wavelengths of an Argon ion laser. The results show a significant variation of the depolarization ratio in the wavelength region between the Soret‐ and β‐bands. The dispersion curves have a different shape for the four Raman lines. Measurements of the depolarization ratio at three pH‐values (pH = 6.3, pH = 7.4, pH = 8.0) and two haemoglobin concentrations (c = 1.2 × 10−4 M, c = 5 × 10−5M) of the solution show that the concentration and the pH‐value change the dispersion curve in a similar way. The depolarization ratio of the 1375‐Raman line at 496.5 nm excitation wavelength was measured for different concentrations in a region between 4 × 10−4M and 4 × 10−5M. With decreasing concentration the DPR increases. This effect is interpreted as being caused by the dimerization of the tetrameric oxyhaemoglobin molecule. The dispersion curves ρ(λ) are interpreted in terms of mode mixing of the molecular vibrations of the haem due to symmetry lowering of its environment. This symmetry change is induced by interactions of the solvent with the charged and polar groups on the surface of the globular protein.
Continuous wave stimulated Raman spectroscopy of the ν1 band of natural GeH4
Authors: Mao S. Q , Saint‐Loup R. , Aboumajd A. , Lepage P. , Berger H. , Robiette A. G. 
Published: May 2005

AbstractThe ν1 band of natural germane (GeH4) has been recorded using a continuous wave stimulated Raman experiment which we describe in this paper. The resolution is about 0.005 cm−1 at 10 Torr pressure. In the first stage of the analysis, the Raman lines were identified thanks to the recent study of the ν1 and ν3 bands made by Lepage, Champion and Robiette. In the second stage, the stimulated Raman data were combined with the infrared data to refine the excited state constants of the isotopic species 70GeH4, 72GeH4 and 74GeH4.
Activités Raman et Infrarouge des Cristaux Piezoélectriques BeSO4, 4H2O et BeSO4, 4D2O. 2—Activité Raman des Modes Polaires
Authors: Pigenet Claude 
Published: May 2005

AbstractLes cristaux BeSO4, 4H2O et BeSO4, 4D2O étudiés par diffusion Raman (4000 à 4 cm−1) montrent tous deux des éclatements TO‐LO qui confirment leur structure à caractère piezoélectrique. Des modes obliques distincts montrent un caractére mixte B2 et E. Des charges dynamiques effectives ont été calculées. Un effet électrooptique a été mis en évidence.
Raman spectra of gases. XXV—nitrocyclopropane
Authors: Durig J. R. , Sun F. Y. , Li Y. S. , Bush S. F. 
Published: May 2005

AbstractThe Raman spectrum of gaseous nitrocyclopropane, cC3H5NO2 has been recorded from 3500 to 30 cm−1. The interesting internal NO2 torsion was observed at 85±2cm−1 from which a barrier to internal rotation in the vapor state of 1680±70 cm−1 (4.8±0.2 kcal mol−1) was calculated. It is shown that this torsional frequency is consistent with the relative intensities of the vibrational excited states in the microwave spectrum. This barrier value is compared to those for several other NO2 substituted hydrocarbons as well as for the corresponding isoelectronic BF2 substituted molecules. The high barrier value supports the structural arguments that there is significant pseudo‐conjugation between the cyclopropane ring orbitals and the substituent NO2 group. A revised vibrational assignment is presented which is compared to the one previously given for the isoelectronic molecule, c‐C3H5BF2, as well as for c‐C3H5BCI2.
Assignment of charge transfer bands for a bridged binuclear metal complex by resonance Raman excitation profiles
Authors: Knorrs Christopher , Gafney Harry D. , David Baker A. , Braunstein Carlos , Strekas Thomas C. 
Published: May 2005

AbstractResonance Raman spectra obtained using laser excitation wavelengths varled to match each of two visible charge transfer absorption bands of a dimeric metal complex with two different diimine ligands vary significantly. The identification of characteristic ligand vibrations leads to the assignment of the two metal‐to‐ligand charge transfer transitions with respect to the ligand which accepts the charge in the excited state. The resonance Raman spectra provide information relating to the complex structures in solution.
A detailed study of the ν1 and 2ν2 region of the raman spectrum of single crystals of KN3
Authors: Khilji M. Y. , Sherman W. F. , Wilkinson G. R. 
Published: May 2005

AbstractA convincing assignment of the bands in the ν1 and 2ν2 internal mode region of the Raman spectrum of single crystals of KN3 has been obtained. The Fermi resonances of the main (14, 14, 14) isotopic species of N and the two rare isotopic species, (14, 15, 14) and (15, 14, 14) have been analysed in detail. The temperature and pressure dependence of the Raman spectrum have been measured, and values of dν/dp calculated for the theoretically non‐resonating ν1 and 2ν2 levels.
Resonance Raman spectra of naphthalene and naphthalene‐d8 anions in THF
Authors: Christesen S. D. , Johnson C. S. 
Published: May 2005

AbstractRaman spectra have been obtained for naphthalene and naphthalene‐d8 anions in tetrahydrofuran. Seven of the nine totally symmetric normal modes were observed, and a normal modes analysis was performed for the planar modes to obtain stretching force constants for the CC bonds. The changes in the force constants resulting from sodium reduction of naphthalene were found to be proportional to changes in τ bond orders obtained from ab initio Hartree‐Fock SCF calculations at the STO‐3G level. Raman shifts resulting from ion pair formation were within experimental errors.
Rare‐earth titanates and stannates of pyrochlore structure; vibrational spectra and force fields
Authors: Vandenborre M. T. , Husson E. , Chatry J. P. , Michel D. 
Published: May 2005

AbstractInfrared absorption and polarized Raman spectra of rare‐earth titanates of pyrochlore structure Ln2Ti2O7 (Ln = Sm, Gd, Yb; Y) and Ln2Sn2O7 (Ln = La, Sm, Gd, Yb, Lu; Y) have been recorded. A valence force field calculation clearly supports the assignment of the frequencies. A comparison of the results with those of homologous zirconates and hafnates is presented.
Raman studies of vibrational and reorientational relaxation in rotator phase perfluorocyclohexane
Authors: Bailey R. T. , Crulckshank F. R. 
Published: May 2005

AbstractVibrational and reorientational relaxation have been studied in rotator phase perfluorocyclohexane using Raman line‐shape analysis. Two totally symmetric bands were investigated in the temperature range from 170 to 300 K. The results were compared with the predictions of the Kubo stochastic line‐shape theory. Activation enthalpies for molecular reorientation were consistent with previous NMR results.
Applications of four‐channel Raman difference spectroscopy to studies in hydrogen‐bonded systems
Authors: Takahashi H. , Asthana B. P. , Häfner W. , Kiefer W. 
Published: May 2005

AbstractWe report in this work on some potential applications and advantages of the four‐channel Raman detection technique developed recently at this laboratory. The capability of recording four different Raman signals simultaneously and processing them electronically by scaling of each signal in order to obtain a desired linear combination, has been fully exploited. The simultaneous measurement of I∥︁ and I⊥ of the Raman spectra of pyridine and a mixture of pyridine+methanol, thus allows us to derive the isotropic Raman bandwidths of ν1 and ν8b vibrations in the hydrogen‐bonded species C5H5N…︁HOCH3 and at the same time very small frequency shifts of vibrations of the non hydrogen‐bonded pyridine (in mixture) as compared to pure pyridine. The smallest shift that could be measured was 0.045 cm−1. It has been demonstrated that four‐channel Raman difference spectroscopy has a distinct advantage for studying the vibrations of complex systems such as a hydrogen‐bonded species.
A Raman study of solubilization of aromatics by non‐ionic surfactants
Authors: Cooney Ralph P. , Healy Thomas W. , Barraclough Colin G. 
Published: May 2005

AbstractRaman spectra of the aromatic solubilizate in the ternary system, non‐ionic surfactant aromatic water, are indicative of benzene in a hydrophobic liquid‐like environment and of pyridine in a hydrophilie, possibly aqueous environment. The non‐ionic surfactants studied were of the alkylphenol‐ and alkyl‐polyoxyethylene type. Addition of traces of water to a solution of Triton X‐100 in benzene leads to the appearance of a water spectrum which suggests that 1:1 hydrogen‐bond complexes between individual ether groups of the polyoxyethylene chain and water have formed in reversed micelles.
Raman studies on dinucleoside monophosphates: 2—perturbation of carbonyl frequencies of purine and pyrimidine dinucleotides by association in aqueous solution
Authors: Gramlich V. , Klump H. , Schmid E. D. 
Published: May 2005

AbstractIntermolecular interactions of guanine‐containing dinucleoside monophosphates in aqueous solution have been investigated by Raman spectroscopy. The measurements show that the dinucleotides ApG, GpA, UpG, GpC and GpG can form ordered structures under the conditions used. The association of these dinucleotides can be monitored by changes of the frequency and intensity of the C=O stretching vibrations due to hydrogen bond formation and by hypo‐ and hyper‐chromic effects in the ring vibrations of the bases.
The Raman and infrared spectra and normal coordinate analysis for 1,2‐diiodotetrafluorobenzene
Authors: Yadav R. A. , Singh I. S. , Sala O. 
Published: May 2005

AbstractThe Raman spectrum of 1,2‐diiodotetrafluorobenzene was recorded in the region 50–2000 cm−1 on a Jarrell‐Ash Model 25–300 double monochromator spectrometer using 5145 Å radiation from an argon‐ion laser. The depolarization ratios of the Raman lines were measured in CS2 and CHCl3 solutions. The infrared spectrum was recorded in CS2 and CHCl3 solutions in the region 180–200 cm−1 on a Perkin‐Elmer 180 spectrometer using a CsI cell. The fundamental vibrations were assigned on the basis of the frequencies and relative intensities of the bands observed in the Raman and infrared spectra and the depolarization ratios of the Raman lines. A normal coordinate analysis was also performed to check the vibrational assignments.