bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic interpretation of Raman spectra of organic compounds. III—carbonyl compounds
Authors: Visser T. , van der Maas J. H.
Published: May 2005

The Raman spectra of 220 carbonyl‐containing compounds have been recorded. The characteristic frequencies are reported. Correlations between frequencies and structure have been investigated. The collected data have been incorporated into a formerly developed and outlined interpretation system for CH, OH and O compounds. Difficulties in modifying the old system are discussed and a schematic survey of the new system is given.
Gitterschwingungsspektren. XIX—infrarot‐ und Ramanspektren von BaBr2·2H2O und BaBr2·2D2O
Authors: Lutz H. D. , Pobitschka W. , Frischemeier B. , Becker R. A.
Published: May 2005

Low temperature infrared and Raman spectra of polycrystalline BaBr2·2H2O at different degrees of deuteration are studied in the frequency range from 4000 to 30 cm−1. The single peaks observed for the bending fundamentals of isotopically dilute H2O and D2O show that the molecules of the water of crystallization are equivalent, as required by Bang's structure determination. The singlets observed for the three fundamentals of isotopically dilute HDO show that there is a symmetric force field in the water molecules which is not predicted from the structure determination. In BaBr2·2H2O weak hydrogen bonds to the bromine ions are present which are largely bent. From the shift of the stretching modes relative to the frequencies of free water the hydrogen bond enthalpy was found to be 20 kJ. The temperature shifts of all the stretching modes are positive, which is not in agreement with Falk's results on bent hydrogen bridges. The internal modes and the twisting libration of the water molecules show an unusual large correlation splitting due to intermolecular coupling of the vibrations of the two water molecules in the 2Br−·2H2O structure unit.
Raman study of phase transitions in plastic solid 1,12‐dicarbaclosododecaborane (para‐carborane)
Authors: Leites L. A. , Bukalov S. S.
Published: May 2005

The infrared and Raman spectra of solid 1,12‐dicarbaclosododecaborane have been studied over the temperature range 10–320 K. Three phases exist in this temperature range. Phases I and II are plastic; phase III is ordered.
Vibrational study of 15N and D substituted guanines in acid and basic solutions
Authors: Delabar Jean‐Maurice
Published: May 2005

Acid and basic solutions of 15N and D substituted guanines have been investigated by infrared and Raman spectroscopy. Monoanion and dianion formation have been followed by spectra changes; N7, N9H tautomery has also been studied by comparing with methylated derivatives. Assignment of the band frequencies have also been proposed. Analysing 15N results have permitted precise comparisons between the neutral form spectra and the anionic or cationic form spectra.

Abbreviations used: IUPAC‐IUB abbreviations are used throughout: m7−Gua or m7 ‐guanine: 7‐methyl‐guanine, etc.
Calculation of the mean polarizability derivatives of hydrocarbon molecules
Authors: Svendsen E. Nørby , Tangaa John
Published: May 2005

The mean polarizability derivatives of CH4, C2H2, C2H4 and C2H6 are calculated through a variational procedure. Satisfactory numerical results are obtained using the CNDO approximation with polarization functions included in the basis set. The frequency dependence of the means polarizability derivative is examined, and the separate contributions from σ and π electrons are calculated for the ethylene molecule.
Molecular interactions and Raman polarization: The depolarization ratio and the Raman isotropic and anisotropic profiles of HCl in various solvents
Authors: Desbat B. , Huong P. V.
Published: May 2005

The isotropic and anisotropic Raman spectra of a diatomic molecule, HCl, have been recorded in the gaseous state, in the liquid state and in solution in various solvents giving increasing interaction with the solute. It will be shown that the depolarization ratio increases with the interaction forces with the solvent, reflecting the appearance of an induced polarizability by molecular interaction on the solute. A linear relationship has been obtained between the ratio of the polarizability component derivatives (α‖/α⟂) and the frequency shift (Vgas—Vsolution). A non‐coincidence of the maximum of the isotropic and anisotropic spectra is also observed and interpreted as resulting from a frequency distribution of a series of solute molecules, involved differently in the interaction with the solvent.
Preresonance Raman scattering of overtones: The scattering of two overtones of benzene in the ultraviolet
Authors: Ziegler L. D. , Albrecht A. C.
Published: May 2005

Raman scattering of two vibrational overtones of benzene is found to undergo strong preresonance enhancement as the excitation frequency approaches the 1B2u state, the lowest lying, forbidden electronic transition at 265 nm. These preresonance active modes are the first overtone of the 606 cm−1 e2g fundamental, which is responsible for the vibronically induced 1B2u intensity, and the first overtone of the 848 cm−1 e1g fundamental, an out‐of‐plane CH bending mode. In order to treat this overtone preresonance Raman behavior theoretically, the molecular polarizability is consistently expanded to second order in nuclear displacements, and thus we consider all preresonance contributions of this order. The leading contributions of strictly dipole‐forbidden electronic transitions to the scattering cross‐section of overtones are exposed. Within this theoretical context it is seen how scattering cross‐section for each of these resonance active overtones is derived from different sources. The preresonance scattering of the 606 cm−1 overtone results from the vibronic activity of this fundamental in the 1B2u transition. On the other hand, the 848 cm−1 overtone derives its 1B2u resonance activity from the change in its fundamental frequency (to 585 cm−1) in this excited electronic state. Furthermore, the 848 cm−1 overtone activity is built upon signifficant background preresonance contributions from other higher lying electronic transitions.
Vibrational perturbation: A chemical aid to assignment. I—Fermi resonance in the ν8 region of isotopic pyridines
Authors: Stidham Howard D. , Dilella Daniel P.
Published: May 2005

Complete Raman data are reported for the ν1, ν6 and ν8 regions of the vibrational spectra of the C2ν deuterium‐labeled pyridines and of their water complexes. Raman data are given for frequency shifts observed when some of these pyridines are dissolved in a selection of hydrogen‐bonding solvents. The complicated ν8 region is afforded definitive assignment based on Fermi resonance between the A1 component of ν8 and the A1 combination tone ν1 + ν6a, as well as on the ways in which these resonances are made or broken when hydrogen‐bonded complexes are formed with the deuterium‐labeled pyridines.
Raman spectra of carbon monoxide adsorbed on oriented crystalline nickel surfaces
Authors: Stencel J. M. , Bradley E. B.
Published: May 2005

Raman spectral results for CO adsorbed at high pressures on Ni(100), Ni(110) and Ni(111) are presented. The bands near 2020 cm−1 due to chemisorbed CO are discussed in relation to site of adsorption and surface cleanliness. Raman spectra of temperature and pressure‐dependent CO adsorption on Ni(100) are also presented.
Raman and infrared spectra of crystalline hydrogen iodide and deuterium iodide
Authors: Anderson A. , Torrie B. H. , Tse W. S.
Published: May 2005

Raman and infrared spectra of the three phases of crystalline HI and DI have been recorded, and mode frequencies corresponding to molecular vibrations, librations and translations are identified. A comparison with the spectra of solid HCl and HBr confirms that only the low temperature phase has an ordered structure. A simple force constant model is described which is used to assign the observed frequencies for this phase.
A 180° microscope sampling and viewing attachment for a laser Raman spectrometer
Authors: Cook B. W. , Louden J. D.
Published: May 2005

A backscattering collection and viewing system for Raman spectroscopy using a microscope is described. Provision of both 90° and 180° collection systems permanently attached to the same monochromator results in a very powerful analytical spectrometer for all solid, liquid and gaseous samples.
An improvement in the Raman spectrometry of very thin films
Authors: Delhaye Michel , Dupeyrat Monique , Dupeyrat René , Lévy Yves
Published: May 2005

Coupling an oblique angle laser illumination system to a four‐media sample structure and a Raman microprobe spectrophotometer allowed us to obtain non‐resonant Raman spectra of very thin Langmuir–Blodgett films. Spectra of films as thin as 75 Å were recorded.
Calibration of a Raman spectrometer using the Kr+ laser plasma lines
Authors: Julien C. , Hirlimann C.
Published: May 2005

We show that the plasma lines of a Kr+ laser can be used for the calibration of a Raman spectrometer. We have tabulated the absolute values of the plasma lines as well as the shift of these lines relative to the laser lines.
Raman and infrared spectra of 2,4,6‐trichlorophenol and 2,4,6‐tribromophenol
Authors: Faniran J. A. , Shurvell H. F.
Published: May 2005

Raman spectra of solid 2,4,6‐trichlorophenol and 2,4,6‐tribromophenol (s‐TCP ands‐TBP) have been recorded at 80 and 300 K. Infrared spectra in the region 4000–200 cm−1have also been recorded of the solids and of dilute solutions in CCl4. Vibrational assignments and qualitative descriptions of the normal modes of these compounds are proposed on the basis of substituted benzene molecules withCssymmetry. Some evidence for intermolecular hydrogen bonding has been found in the solid state infrared spectra of both compounds, but they do not appear to self‐associate in CCl4solution.
pH‐induced modification of NAD and NADH solutions detected by Raman spectroscopy
Authors: Barrett T. W.
Published: May 2005

Analysis of the Raman spectra of NAD and NADH indicates that the intensity characteristic of a band at ˜ 1400 cm−1, assigned to the nicotinamide ring vibrations, demonstrates interactive effects correlated with conformational changes of NAD in basic phosphate solutions and NADH in acid phosphate solutions. The Raman lines of these dinucleotides are discussed with respect to the spectra of the individual bases and previous Raman studies of nucleotides. The data reported provide the groundwork for future application of the Raman technique to NAD and NADH reactions.
Second order Raman spectrum of carbon disulphide in the condensed phase
Authors: Umapathy S. , Kesavasamy K. , Krishnamurthy N.
Published: May 2005

Below 162K, carbon disulphide crystallizes in the space group D2h18 with two molecules in the primitive cell. The internal modes v1, v2 and v3 of the isolated CS2 molecule are split due to static and correlation field splittings. Anderson et al. have extensively studied the Raman and infrared spectra of CS2 at 79 K and 18 K and have analysed the internal and external modes with a lattice dynamical calculation of the q = 0 phonons. However, their spectra reveal the presence of extensive second order features accompanying the v1, v2, v3 and 2v1 bands. The present investigation attempts an interpretation of these second order Raman spectra employing Born's theory and the lattice dynamical calculation of phonons at all allowed q points in the Brillouin zone employing the rigid molecule approximation.
The CF3 Rotor: Torsional vibrations for some CF3OX and CF3OOX molecules
Authors: Hammaker R. M. , Fateley W. G. , Manocha Ajit S. , Desmarteau D. D. , Streusand B. J. , Durig J. R.
Published: May 2005

The low frequency Raman spectra of CF3OF (gas, liquid), CF3OCI (liquid), CF3OOH (gas, liquid), CF3OOD (liquid), CF3OOF (gas, liquid) and CF3OOCI (liquid) have been recorded below 300 cm−1. The spectra have been assigned and the CF3 torsional modes were observed for all of these compounds in the liquid state. The assigned frequencies for the liquids and the calculated barriers for the vapor state are: CF3OF, ντ = 144 cm−1, V3 = 4.64 kcal mol−1; CF3OCI, ντ = 122 cm−1, V3 = 4.6 kcal mol−1; CF3OOH, ντ = 155 cm−1, V3 = 6.0 kcal mol−1; CF3OOF, ντ = 78 cm−1, V3 = 2.9 kcal mol−1; and CF3OOCI, ντ = 80 cm−1, V3 = 3.7 kcal mol−1. The assignments are discussed and the barriers are compared to the corresponding quantities in some similar molecules.
Le Spectromètre Raman comme Détecteur Séleitif de la Chromatographie en Phase Liquide
Authors: Chapput André , Roussel Bernard , Montastier Jacques
Published: May 2005

The purpose of this work is to show that it is possible to use microcells in Raman spectroscopy to detect chemical species in various solvents at low concentrations in order to connect a liquid chromatograph with a Raman spectrometer. Several methods are described in static as well as in dynamic processes.
Vibrational dephasing in polar molecular liquids: An application to a fundamental and its overtone in phenyl acetylene
Authors: Baglin Frank Geile
Published: May 2005

Based upon the results reported here for phenyl acetylene and the results of other investigators' studies, a working model of phase relaxation in polar molecular liquids is proposed. The model rests upon the established concept of a phase annihilation operator1 and a postulated phase conduction band structure for polar molecular liquids. Three cases are discussed; briefly, they are (I) no effect upon the signal of interest by dilution, (II) narrowing of the signal of interest by dilution, and (III) broadening of the signal of interest by dilution. The latest effect has not been elucidated previously in the literature. Actual examples of each of these cases are discussed. Phenyl acetylene's vcc and 2vcc modes are shown to display Case II behavior. These two modes are found in the Raman spectrum at 2113 cm−1 (vcc) and 4205 cm−1 (2vcc). They have been examined by varying the concentration of this molecule in two dipolar solvents, a quadrupolar solvent and an octopolar solvent. In addition, temperature studies on the neat sample were carried out at 10–30 K intervals for vcc and at 275 K and 90 K for 2vcc. From the results of our investigation, a relaxation mechanism consistent with a quadrupole–quadrupole dephasing type mechanism is postulated for both vcc and 2vcc.
Vibrational spectra and normal coordinate analysis of CF3OF and CF3OCl
Authors: Kuo J. C. , Desmarteau D. D. , Fateley W. G. , Hammaker R. M. , Marsden C. J. , Witt J. D.
Published: May 2005

The IR spectra (1400 cm−1 to 160 cm−1) of the gases at ambient temperature and the Raman spectra (below 1400 cm−1) of the liquids near −196°C are reported for CF3OF and CF3OCl. All fundamentals are assigned under Cs symmetry and the results of a normal coordinate analysis are presented. The assignments of Smardzewski and Fox are adopted with one exception for both CF3OF and CF3OCl: the CF3 rock of A″ symmetry is assigned near 430 cm−1 and the two bands between 200 cm−1 and 300 cm−1 are assigned to an A′ fundamental, involving CF3 rocking and COX bending and a Δν=2 transition in the CF3 torsion. An extra band at 548 cm−1 in the Raman spectrum of liquid CF3 COl near −196°C is assigned to a CF3OCl ⃛Cl2 complex. The values of the force constants d(OX) for CF3OX molecules are suggested to be near those for X2O molecules. More than half the normal modes of A′ symmetry show extensive mixing of symmetry coordinates. In some of these cases the symmetry coordinate for which the normal mode is named is the largest but not the dominant contributor to the potential energy distribution, while in others this symmetry coordinate is not even the largest contributor to the potential energy distribution. No normal modes of A′ symmetry are present in which ν(CO), δs(CF3), δ(COX), or δ(CF3) symmetry coordinates are dominant, and the mode conventionally labeled as v(CO) should be labeled as νs(CF3). For the remaining A′ normal modes and all the A″ normal modes, the symmetry coordinate for which the normal mode is named is dominant in the potential energy distribution.
Vibrational spectra of C2ν deuterium substituted pyridines. 3—pyridine‐3,5‐d2 and pyridine‐3,4,5‐d3
Authors: Dilella Daniel P.
Published: May 2005

Pyridine‐3,5‐d2 and pyridine‐3,4,5‐d3 have been prepared. Isotopic constitution and label specificity of each of several preparations were verified by mass spectrometry and proton NMR. Liquid phase Raman and both liquid and vapor phase infrared spectra of these molecules are reported. Vibrational assignments consistent with frequency sum and product rule constraints are proposed. The relative rates of base‐catalyzed exchange of hydrogen with deuterium for the ring positions of pyridine‐N‐oxide were estimated during the course of the synthetic work. It is found that the 2 and 6 positions exchange very readily, that the 3 and 5 positions exchange slowly, and that the 4 position exchanges very slowly.
Vibrational spectra of C2ν deuterium substituted pyridines. 4—pyridine‐2,3,5,6‐d4 and pyridine‐d5
Authors: Stidham Howard D. , Dilella Daniel P.
Published: May 2005

Pyridine‐2,3,5,6,‐d4 has been prepared. The isotopic composition and label specificity of each of three preparations were verified by mass spectroscopy and proton NMR. The liquid phase Raman and the liquid and vapor phase infrared spectra of pyridine‐2,3,5,6‐d4 and pyridine‐d5 at room temperature are reported. The vibrational spectra of these compounds are completely analyzed and a summary of the assignment for all eight C2ν deuterium labeled pyridines is given.
Vibrational spectra of mercury(II) dihydrogen phosphate, mercury(II) phosphate and mercury(I) selenate
Authors: Russell Stephen J. , Tan Kang‐Hai , Taylor Michael J.
Published: May 2005

Raman and IR spectra of the crystalline solids Hg2(H2PO4)2, Hg3(PO4)2 and Hg2SeO4 are reported and assigned in terms of vibrational modes of the unit cell. Frequencies v (HgO) and v (HgHg) are located in the ranges 210–280 and 180–190 cm−1, respectively. Inter‐ and intramolecular coupling of HgO modes, and of some ligand vibrations, result in splittings of from 5 to 40 cm−1, which can be related to the crystal and molecular structures.
Vibrational spectra and conformations of (chloromethyl)cyclopropane and epichlorohydrin
Authors: Kalasinsky V. F. , Wurrey C. J.
Published: May 2005

The IR and Raman spectra (4000–50 cm−1) of (chloromethyl)cyclopropane and epichlorohydrin have been recorded in all three physical states. It has been concluded from the spectroscopic data and from variable temperature studies that (chloromethyl)cyclopropane exists as an equilibrium mixture of gauche (95%) and cis (5%) conformers in the liquid state, while only the gauche form persists in the solid phase. The enthalpy difference between these two rotamers was found to be 1.40±0.10 kcal mol−1. Similarly, epichlorohydrin has also been shown to exist as an equilibrium mixture of gauche‐1 (70%), gauche‐2 (21%) and cis (9%) conformers in the liquid state, with only the gauche‐1 form remaining in the solid phase. Enthalpy differences among these conformers were determined to be 1.2±0.2 kcal mol−1 (gauche‐1 vs. cis) and 0.70±0.10 kcal mol−1 (gauche‐1 vs gauche‐2). Apparently steric repulsions between the chlorine atom and β ring‐hydrogens destabilize the cis conformation in each molecule. For each molecule, a vibrational assignment has also been proposed.
Fluorescence‐free resonance Raman spectra of reduced nicotinamide adenine dinucleotide via ultraviolet excitation
Authors: Bowman W. David , Spiro Thomas G.
Published: May 2005

Excitation of reduced nicotinamide adenine dinucleotide (NADH) on the high‐energy side (333.6 nm) of its ultraviolet absorption band shifts the Raman scattering away from the fluorescence band and produces a good quality resonance Raman spectrum. It is dominated by the amide I (CO stretch) mode, at 1687 cm−1, but several weaker bands are observed, and are tentatively assigned to amide II and III, and ring modes, consistent with N2H2 and 4‐2H isotope shifts. An identical spectrum is observed for nicotinamide mononucleotide (NMNH), indicating that the adenine and nicotinamide portions of NADH do not interact.
Selective ultraviolet resonance Raman excitation of individual chromophores in nicotinamide adenine dinucleotide
Authors: Rodgers Edward G. , Peticolas Warner L.
Published: May 2005

Ultraviolet resonance Raman spectra (UVRRS) of reduced nicotinamide adenine dinucleotide (NADH) has been taken with ultraviolet laser excitation wavelengths (λe) of 273 nm, 330 nm and 351.1 nm. These Raman spectra have been compared with the resonance Raman spectra of the model compounds adenosine mononucleotide phosphate (AMP), with λe = 300 nm, and with reduced methyl nicotinamide (MNH), with λe = 351.1 nm, and with the classical Raman spectrum of NADH, with λe = 514.5 nm. The UVRR spectrum of NADH with λe = 273 nm resembles exclusively that of AMP while the UVRR spectra with λe = 330 nm and λe = 351.1 nm show no AMP bands but only those of MNH. The classical Raman spectrum of NADH is shown to be a superposition of bands in the resonance Raman spectra of the two chromophores but includes as well the sugar‐phosphate bands. Thus it is possible selectively to excite a UVRRS of either chromophore independently of the other. This information may prove helpful in developing techniques of UVRRS in studying NADH‐enzyme complexes since only very dilute (˜5×10−4 M) concentrations of NADH are needed for the resonant Raman spectra.
Solid state vibrational spectroscopy. 10—A kinetic study, using Raman spectroscopy, of the solid state thermal decompositions of sodium and potassium dithionate
Authors: Cleaver Kevin D. , Davies J. Eric D.
Published: May 2005

The kinetic behaviour of the solid state thermal decomposition of dithionate to sulphate, M2[S2O6] → M2[SO4], M = Na, K, has been studied by following the temporal decrease in the intensity of the Raman band arising from the vs(SO3) mode of [S2O6]2−. The sodium salt displays first order kinetics, but the kinetic behaviour of the potassium salt could not be accounted for using either the conventional kinetic treatment or the Avrami–Erofeev treatment. The Raman derived data for the sodium salt agree well with previously reported pressure derived data supporting the contention that Raman spectroscopy is a valid technique to use in obtaining solid phase kinetic data.
Raman scattering from alkali graphite intercalation compounds
Authors: Solin S. A. , Caswell N.
Published: May 2005

The stage dependences of the Raman spectra of potassium, rubidium and cesium graphite intercalation compounds are reported. The spectra of each set of compounds are found to be qualitatively and quantitatively consistent with the ‘nearest layer’ model for the carbon intralayer E vibrations of intercalation compounds. To within experimental error the charge exchanged from the intercalant layers to the carbon layers is found to be stage independent and partially localized in type B carbon layers which are contiguous to intercalant layers. The relative Raman cross‐section for scattering from type B and type C (noncontiguous) carbon layers is found to be species independent and is σC/σB = 0.25 ± 0.05.
Resonance Raman spectrum of the transient dimethylsulfide dimer radical cation |(CH3)2S|2+·
Authors: Wilbrandt R. , Jensen N. H. , Pagsberg P. , Sillesen A. H. , Hansen K. B. , Hester R. E.
Published: May 2005

The resonance Raman spectrum of the transient thioether radical cation dimer complex |(CH3)2S|2+·, generated by electron irradiation of an aqueous solution of dimethylsulfide and recorded by optical multichannel detection, is reported. Vibrational bands at 276 cm−1 and 139 cm−1 were detected and are assigned to the stretching mode of the quasi‐three‐electron SS bond and a δ(CSS) deformation mode, respectively.
Low‐frequency vibrations (20–400 cm−1) of some mononucleotides in aqueous solutions
Authors: Nielsen O. Faurskov , Lund P. ‐A. , Praestgaard E.
Published: May 2005

Low‐frequency Raman scattering (20–400 cm−1) of aqueous solutions of 5′‐monophosphates of uridine (UMP), cytidine (CMP), guanosine (GMP) and of adenosine (AMP) are studied by construction of a quantity R (ν). The frequencles for intensity maxima below 100 cm−1 depend upon the protonization or the purine and pyrimidine rings, but not upon ionization of the phosphate groups. An assignment to modes very similar to corresponding nucleoside modes is discussed.
Raman active torsion‐libration overtones in crystalline N2H6Cl2 and N2H6Br2
Authors: Ratcliffe C. I. , Sherman W. F. , Wilkinson G. R.
Published: May 2005

Raman active torsion‐libration fundamentals and overtones have been observed in crystals of N2H6Cl2 and N2H6Br2. The temperature dependences of these modes have been followed between liquid nitrogen and room temperatures in the case of the chloride. Potential barriers to rotation have been calculated and compared with NMR activation energies to gain insight into the relationship between the two kinds of result. The external barrier for NH3+ reorientation and the internal barrier for N2H62+ have been found to be 3597 and 709 cm−1 respectively for the chloride at 73 K, and 3066 and 676 cm−1 respectively for the bromide at 92 K. The chloride results clearly show that the barriers are slightly temperature dependent. It is concluded that the NMR activation energy for NH3+ reorientation must also have a temperature dependence which is probably of the form Ea = Ea′ ‐ CT. The discrepancies between the two types of results have been tentatively interpreted in terms of small sixfold contributions to the barriers.
Raman spectra of gases: 24—Phenol
Authors: Wilson H. William , Macnamee R. W. , Durig J. R.
Published: May 2005

The medium resolution Raman spectrum of gaseous phenol has been recorded between 4000 and 50 cm−1 using the 5145 Å line of an argon laser. A number of a′ bands have been observed which correspond to previously assigned normal modes, but lines at 1388 and 1285 cm−1, which are not normally observed in the infrared spectrum of the gas, have been assigned as fundamentals. In addition, a strong Raman band at 1007 cm−1 is probably an overtone of an out‐of‐plane vibration at 503 cm−1 in resonance with a nearby a′ fundamental. Two bands at 824 and 810 cm−1 were both found to belong to the symmetric a′ species. Previous assignments have dealt with these two bands as having different symmetries. A reassignment of some of the fundamentals of phenol may be necessary to account for these Raman observations.
Raman spectroscopic study of PCl5‐AlCl3 melts
Authors: Poulsen Finn Willy
Published: May 2005

Raman spectra have been recorded from PCl5‐AlCl3 melts containing 30,50,63.7,70,80 and 90 mol% AlCl3, respectively. Raman shifts were identified from the species: PCl5, PCl4,+ AlCl4,− AlCl7− and Al2Cl6. A higher AlxCly−z complex exists in melts with more than 70 mol% AlCl3 and is characterized by Raman shifts of 100, 297 and 395 cm−1. The relative molar scattering intensities of the strongest MCl stretching vibrations of the melt species have been estimated relative to the intensity of the total symmetric stretching vibration of tetrahedral PCl4+.
Spectroscopic and thermodynamic studies of unsaturated nitrile compounds: 2—The infrared and Raman spectra, normal coordinate analysis and values for the ideal gas thermodynamic functions of 3‐methyl‐2‐butenenitrile
Authors: Compton D. A. C. , Murphy W. F. , Mantsch H. H.
Published: May 2005

A study of the vibrational spectrum of 3‐methyl‐2‐butenenitrile has been carried out. The infrared spectra above 625 cm−1 of the gaseous, liquid and solid states, and the Raman spectra of the liquid and solid states are reported. An assignment has been made for the observed vibrational frequencies with the aid of a normal coordinate treatment. Estimates were made for the torsional barrier heights and frequencies of the two methyl groups, but only one of the torsional frequencies could be located. Values for the thermodynamic functions of the ideal gas were calculated using the observed spectroscopic data; contributions due to the torsional motions were calculated from the estimated barrier heights.
Configuration‐dependent Raman bands of phospholipid surfaces: 2—Head group and acyl stretching modes in the 800–900 cm−1 region
Authors: Bicknell‐Brown Ellen , Brown Kenneth G. , Person Willis B.
Published: May 2005

Deuteration studies, hydration studies, melting studies and model compound studies are utilized to assign and interpret the 800–900 cm−1 region of the Raman spectra of the phospholipids dipalmitoyl phosphatidylcholine and dipalmitoyl phosphatidylethanolamine. Head group Raman bands in this region are shown to be sensitive to hydration and melting. The acyl carbon‐carbon stretches, assigned to Raman bands appearing at 860–890 cm−1, are shown to be sensitive probes of molecular packing order, specifically in the acyl interface region.
Determination of anharmonicity constants from the Raman spectrum of gaseous acetylene
Authors: Finsterhölzl H. , Schrötter H. W. , Strey G.
Published: May 2005

From an analysis of the photoelectrically recorded Raman band of acetylene at 3950 cm−1, which contains contributions from ν1+ν4 and its hot bands, ν3+ν5 in Fermi resonance with ν2+ν4+2ν5, and the Q‐branch of 2ν2, some anharmonicity constants were determined. In particular x22= −7.4 cm−1 was obtained directly for the first time, other constants are revised due to a more complete consideration of the resonance perturbations. A computer simulation of the ν4 fundamental and the ν1+ν4 combination band shows excellent agreement with the experimental spectra.
Rotational isomers of ethyl dithioacetate and ethyl thionoacetate: A Raman study
Authors: Verma A. L. , Ozaki Y. , Storer A. C. , Carey P. R.
Published: May 2005

Raman spectra of ethyl dithioacetate (CH3CS2C2H5) and ethyl thionoacetate (CH3C(S)OC2H5) have been measured as a function of temperature in the liquid phase and in the solid phase at low temperature. For both compounds disappearance of several bands from the liquid spectrum on solidification established the presence of more than one conformer in the liquid phase. Temperature variation studies on band pairs whose components belong to different isomers gave enthalpy differences of 598±48 cal mol−1 and 1072±65 cal mol−1 between the conformers of CH3CS2C2H5 and CH3C(S)OC2H5 respectively. The most probable low‐energy conformer, in both instances, is the s‐cis form with all the heavy atoms contained in a single plane.
Structures of HCI and HBr polymers in nitrogen matrix derived from infrared and Raman data: Comparison with argon matrix
Authors: Perchard J. P. , Maillard D. , Schriver A. , Girardet C.
Published: May 2005

The structures of HCI and HBr polymers trapped in nitrogen matrices are re‐examined at the light of new Raman data. From the comparison with IR vibrational spectra including H/D decoupling experiments, two polymers other than the dimer are identified: an assymetric cyclic trimer in which the three molecules are not equivalent, and a cyclic tetramer in which the molecules are equivalent in pairs. In the case of HCI the trimer is seen to exist with two slightly different forms below 20 K, one of them reversibly disappearing above this temperature. The differences with the results obtained in rare gas matrices are understood as occurring from a strong anisotropic solute‐matrix potential which tends to distort the highly symmetric structure of isolated aggregates. The distorsion is perhaps at the origin of the change in the derivatives of some molecular electrical properties with respect to the intermolecular stretching coordinate from rare gas to nitrogen matrices.
Enhanced Raman spectra of coadsorbed carbon monoxide and hydrogen on small nickel particles
Authors: Krasser W. , Renouprez A. J.
Published: May 2005

We have used vibrational Raman spectroscopy to study the chemisorption of carbon monoxide and of ethylene, and the chemical interactions of coadsorbed carbon monoxide and hydrogen on silica‐supported nickel particles. In each case we observe a strong enhancement of all measured vibrational bands which depends on the excitation wavelength. The maximum enhancement lies always in the excitation wavelength range 5200–4500 Å. The enhancement is of the order 102−104. The complex spectra from coadsorbed CO and H2 indicate the formation of several surface species: adsorbed carbon monoxide, hydrocarbon‐like species, and different oxygen‐containing hydrocarbon compounds. A complete assignment of all vibrational bands is not possible because of the complexity of the Raman spectra.
The hyper‐Raman effect in molecular gases
Authors: Altmann K. , Strey G.
Published: May 2005

The 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

The 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

Infrared 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

The 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

The 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

A 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

N‐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

The 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

Resonance 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

The 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

The 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

A 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

A 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

Several 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

The 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

The 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

A 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

Measurements 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

The 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

Les 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.