bluuebunny/crossref_metadata_2025 huggingface dataset:
Resonance Raman spectroscopy of heme proteins with intensified vidicon detectors: Studies of low frequency modes and excitation profiles in cytochrome c and hemoglobin
Authors: Yu Nai‐Teng , Srivastava R. B.
Published: May 2005

We have designed and assembled a sensitive vidicon Raman spectrometer which is shown to be well suited for the studies of heme proteins in both Soret (near‐ultraviolet) and Q (visible) band regions. This system, employing a dry ice‐cooled silicon intensified target (SIT) detector and an additive dispersion double monochromator (two 600 g mm−1 gratings blazed at 400 nm), has excellent stray light rejection and optimum bandpass and resolution (5–12 cm−1) for biological applications. It is demonstrated that a 600 cm−1 wide section of the low frequency Raman spectrum of ferrocytochrome c excited at 413.1 nm (70 mW) can be obtained in 30 ms, which is ˜ 2×104 times faster than that required by the conventional scanning techniques. Our multichannel Raman system has an enhanced detection capability which enables us to identify at least 41 weak Raman lines below 850 cm−1 in the spectrum of ferrocytochrome c. Using the SIT detection system, the Raman excitation profile of a depolarized line at 750 cm−1 in Fe(II) cytochrome c has been constructed and compared with that reported for Ni etioporphyrin. Instead of strong 0–0 Raman intensity, the cytochrome c profile exhibits weaker 0–0 intensity, indicative of the absence of the Jahn‐Teller effect. It is further demonstrated that the Soret‐excited Raman spectrum of oxyhemoglobin can be readily obtained without photodissociation.
Orientation des Phases par Etirage dans le Polyéthylène: Etude par Effet Raman
Authors: Luu Dang Vinh , Cambon Louis , Lafont Robert
Published: May 2005

Research on the polarization of bending vibrations of CH2 makes it possible to deduce the orientation of the different phases of polyethylene. When the sample is stretched, the orthorhombic monocrystalline phase becomes parallel to the stretching axis but the other two phases take a more or less perpendicular direction.
Raman spectra of molten SbCl3/AlCl3mixtures
Authors: Huglen R. , Mamantov G. , Begun G. M. , Smith G. P.
Published: May 2005

Raman spectra were obtained for nine molten mixtures of SbCl3and AlCl3, as well as for the pure components. Also three molten mixtures of AlCl3/NaCl/SbCl3were studied. Molten AlCl3contains molecular Al2Cl6(D2h) while molten SbCl3contains pyramidal (C3v) molecules aligned head to tail. The Raman spectra showed the presence of Al2Cl6molecules in molten SbCl3/AlCl3mixtures containing 40 mol% or more AlCl3but gave no evidence for the formation of SbCl2+and AlCl4−. However, SbCl3is structurally modified by the addition of AlCl3as seen from the shift of the highest SbCl stretching frequency. There is also spectral evidence that points to the formation of polymers that are different from those in pure SbCl3, and it cannot be ruled out that there may be a chloride‐deficient antimony species in the AlCl3‐rich mixtures. The molecular nature of the observed modifications in these mixtures cannot be deduced solely on the basis of the recorded spectra.
Resonance Raman spectra of D and 15N isotopes of methyl orange in aqueous solutions
Authors: Machida Katsunosuke , Lee Hohi , Kuwae Akio
Published: May 2005

Resonance Raman spectra of methyl orange and its ring‐deuterated and azo‐15N‐substituted derivatives have been recorded in neutral aqueous solution and in solutions in 0.1 M hydrochloric and deuteriochloric acids. Band assignments have been given by referring to the isotope shifts, and on that basis the structures of the base and the acid forms of the dye molecule in the lowest electronic excited state are discussed.
Raman and infrared spectra and structure of some caesium monohalocyanoiodate (I) salts, Cs[XICN] (XCl, Br or I)
Authors: Chadwick B. M. , Fawcett V. , Long D. A. , Qureshi S. U.
Published: May 2005

The [I2CN]− ion, previously only known in aqueous solution, has been isolated as its caesium salt; and the previously unknown [BrICN]− ions [ClICN]− have been isolated as their caesium salts. The Raman and IR vibrational spectra of these three caesium salts have been investigated in detail and indicate that the halide ions coordinate to the I atom of ICN to form linear (C∞ν) [X—I—CN]− ions (X=I, Br or Cl), contained in a centrosymmetric unit cell. This C∞ν structure is supported by a normal coordinate analysis for the [IICN]− ion.
Vibrational spectra and structure of cyclopentylamine
Authors: Kalasinsky V. F. , Little T. S.
Published: May 2005

The Raman spectra of gaseous, liquid and solid cyclopentylamine and the infrared spectra of the gaseous and solid phases have been recorded. Raman depolarization ratios and infrared band contours in the gas phase indicate that cyclopentylamine exists primarily with a gauche orientation of the —NH2 group, and the torsional fundamental for this conformer has been observed at 232 cm−1. In the solid state the temperature characteristics in certain spectral regions are consistent with the existence of two low temperature phases, and the higher temperature phase appears to exist over a range of approximately only 7°C. A complete vibrational assignment is proposed, and the structural features of cyclopentylamine are discussed.
Low frequency vibrations (20–400 cm−1) of some mononucleosides in aqueous solution
Authors: Nielsen O. Faurskov , Lund P.‐A. , Praestgaard E.
Published: May 2005

Low frequency Raman scattering (20–400 cm−1) of aqueous solutions of uridine, cytidine, guanosine and adenosine are studied by the recently described construction of a quantity R(ν). Bands with intensity maximum at frequencies below 100 cm−1 are assigned to specific protonized forms. An assignment of these bands to nucoleoside modes is preliminarily discussed.
Laser excited Raman spectroscopy of biomolecules. 13—conformational study of α‐chymotrypsin and trypsin
Authors: Chen Michael C. , Lord R. C.
Published: May 2005

The Raman spectra of bovine pancreatic α‐chymotrypsin and trypsin were determined from 7% aqueous solutions and lyophilized solids containing residual sulfate ion. A large amount of β‐pleated‐sheet structure is present in both molecules, as shown by the contour of the amide III region, but trypsin contains substantially more α‐helical conformation than does chymotrypsin. There is evidence of some change in structure of both molecules in solution as compared with the solids. The tyrosines are all or nearly all weakly hydrogen bonded in both enzymes, and the binding of sulfate ion is also weak in the lyophilized solids.
Solid state vibrational spectroscopy. 8—A thermochemical and vibrational spectroscopic study of the solid state thermal decompositions of alkali metal peroxydisulphates
Authors: Cleaver Kevin D. , Davies J. Eric D.
Published: May 2005

The solid state thermal decompositions of the alkali metal peroxydisulphates M2[S2O8], M = Na, K, Rb, Cs, have been studied using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), in situ high temperature Raman spectroscopic studies, and by recording the infrared and Raman spectra of the products formed when the salts are heated to various temperatures. In addition to detecting the exotherm associated with the decomposition of peroxydisulphate to pyrosulphate and the endotherm associated with the fusion of pyrosulphate, the DSC study detected previously unreported solid state phase changes of Cs2[S2O8] and K2[S2O7]. These phase changes are also detectable using Raman spectroscopy. The TGA study indicates the formation of an intermediate in the decomposition of pyrosulphate to sulphate, but it is not possible to determine its stoichiometry from the TGA study.
Raman effect: History of the discovery
Authors: Krishnan R. S. , Shankar R. K.
Published: May 2005

The paper gives a historical account of the discovery of the Raman Effect, starting from Raman's voyage to Europe through the Mediterranean Sea in the summer of 1921 to the observation of modified lines in benzene when illuminated by the 435.8 nm radiations of mercury, through a direct vision spectroscope, on 28 February 1928. The important contributions of Raman and his students during the period which form the progressive stages in the road to discovery have been briefly touched upon. The work of the French group, the Russian group and the theoretical work of Smekal are narrated in sequence.
Polarization techniques in coherent Raman spectroscopy
Authors: Levenson Marc D.
Published: May 2005

The advantages of performing coherent Raman spectroscopy with definite input and output polarizations are reviewed. Methods are described for evaluating Raman susceptibility tensor elements, depolarization ratios and nonresonant contributions to the third order nonlinear susceptibility. A systematic development of the signal‐to‐noise ratio reveals the advantages of incomlete suppression of the nonresonant background signal. Results obtained using coherent Stokes and anti‐Stokes Raman spectroscopy, the Raman‐induced Kerr effect and four‐wave mixing are also reviewed with emphasis on liquids and solids.
Interaction of optical phonons with 4f electrons in CecNd1–cF3
Authors: Leiteritz K. , Schaack G.
Published: May 2005

Using Raman spectroscopy we have studied some effects of the 4f electron–phonon (magnetoelastic) coupling in CecNd1–cF3 (0 ≤c≤1). This coupling manifests itself in the splitting of some twofold degenerate phonons in a magnetic field, accompanied by a reduction in linewidth, and in a zero‐field shift of phonon frequencies all depending on c. We have also studied the low lying (electronic) crystal field states of Nd3+(4I9/2) in NdF3 and determined the eigenfunctions which have been used for a theoretical interpretation of the magnetoelastic effects in NdF3.
Vibrational spectra and structure of organophosphorous compounds. 20—infrared and raman spectra, vibrational assignment and normal coordinate calculations of methyldifluorophosphine
Authors: Durig J. R. , Stanley A. E. , Jalilian M. R.
Published: May 2005

The Raman spectra of gaseous, liquid and solid CH3PF2 and the infrared spectra of the gas and solid have been recorded (3200–20 cm−1). The assignment of the 15 fundamentals is given and discussed and is based on the gas phase infrared band contours, depolarization values and group frequencies. A normal coordinate calculation was carried out by utilizing a modified valence force field to calculate the frequencies and the potential energy distributions. Extensive mixing was found between the PF2 stretching and CH3 rocking modes. The methyl torsion was observed at 192 cm−1 in the far‐infrared spectrum of the gas and from this frequency a three‐fold barrier to internal rotation of 1.74 kcal mol−1 was calculated. This value is compared to similar quantities in several other group VA compounds and the observed trends are consistent with those for the corresponding group IVA compounds.
Microprocessors: Applications to Raman and Brillouin spectroscopy
Authors: Rowell N. L. , Lockwood D. J. , Grant P.
Published: May 2005

Automation techniques based upon the latest microprocessor computer technology are described in general terms for applications in light scattering spectroscopy. Two practical systems are described in detail. The first system operates a Raman spectrometer and handles the data collection automatically, storing the spectrum in digital form on disc and providing visual displays simultaneously. The second controls the alignment and scanning of a multi‐pass Fabry‐Perot spectrometer as well as data acquisition. Finally, prospects for future systems are reviewed.
Oblique phonons in uniaxial molecular crystals: Raman spectra of s‐trioxane
Authors: Kubinyi M. , Castellucci E.
Published: May 2005

Using Raman scattering the angular dispersion of extraordinary phonons in s‐trioxane, a uniaxial crystal of trigonal structure, has been measured. It has been found that the transitions are of the type TO → LO or LO → TO so that the anisotropic short‐range forces predominate over the long range electrostatic ones. The LO–TO splittings are of the order of 10 cm−1 or less as expected for molecular crystals. For phonon propagation direction along the optic axis extraordinary and ordinary phonons of E species coincide.
Raman and infrared studies of the hydrogen halide crystals
Authors: Anderson A. , Torrie B. H. , Tse W. S.
Published: May 2005

Raman and infrared spectra of polycrystalline samples of HCl, HBr, HI, HF and their deuterated analogues are briefly reviewed and correlated with crystal structures and molecular properties. A simple force constant model is used to describe the vibrations of these crystals in their low temperature ordered phase and to obtain estimates of their hydrogen bond strenghts.
Raman scattering by magnetic excitations in disordered FeF2
Authors: Rezende S. M. , de Araujo Cid B. , Montarroyos E.
Published: May 2005

Inelastic scattering of light has been used to study the magnetic excitations in antiferromagnetic FeF2 crystals disordered in two ways. In the first the magnetic dilute system Fe1–xZnxF2 is investigated as a function of the concentration x and temperature T, with x varying from zero nearly up to the percolation limit xp = 0.76. The other is the mixed system Fe1–xMnxF2 in the limit of small Mn impurity concentrations. In this case an anomalously large scattering by the impurity associated local modes is observed. The behaviour of the excitations in both magnetic systems is explained satisfactorily by simple theoretical models.
Theory for continuum resonance Raman scattering in diatomics using irreducible spherical tensors
Authors: Baierl P. , Kiefer W.
Published: May 2005

A theory is presented which describes resonance Raman scattering via continuum electronic states of diatomic molecules. It is applied to the dissociative continuum of the bounded B(3Πo+u)‐state and the continuum of the repulsive 1Π1u state of the halogen molecules. Using spherical tensors and Wigner 3‐j symbols, closed forms for the resonance Raman intensities for different polarizations are given, which allow first principle calculations for molecules for which the vibrational wavefunctions of ground and electronic excited states as well as the oscillator strengths are known from absorption of fluorescence data.
The second order Raman spectrum of liquid tetrachloroethylene
Authors: Schmid W. J. , Schrötter H. W.
Published: May 2005

The Raman spectrum of liquid tetrachloroethylene in a capillary cell of 20 m length was recorded and about 20 new second order Raman lines were detected in addition to the previously known ones. Using a rectangular cell the depolarization ratios of many of the second order lines were determined and an assignment is given.
The influence of lasers on experimental and theoretical studies of second order Raman spectra
Authors: Hardy J. R. , Karo A. M.
Published: May 2005

The history of experimental and theoretical studies of second order Raman spectra is illustrated by studies that have been made on sodium chloride. It is shown how the introduction of polarized laser sources radically transformed the experimental situation by demonstrating that the observed spectra are highly sensitive to scattering geometry and drastically different from previous results obtained using unpolarized mercury are sources. This necessitates abandonment of previous interpretations of these spectra as simple maps of the two‐phonon joint density of states. Results are presented which show how the inclusion of the Raman polarizability in the scattering calculations, using a simple phenomenological model, also dramatically alters the predicted spectra. Moreover, it does so in such a way as to produce the same degree of agreement between theory and experiment as existed between the earlier spectra and the joint density of states. A short overview of attempts to refine the theory further is presented. It is concluded that subsequent extensions of phenomenological and semi‐phenomenological theories, amied at producing a precise fit to the observed spectra, are not satisfactory. It is therefore argued that attempts be made in the future to derive the Raman polarizabilities from first principles.
Normal mode determination in crystals
Authors: Rousseau D. L. , Bauman R. P. , Porto S. P. S.
Published: May 2005

The group theoretical methods by which the symmetries of normal modes in crystals may be determined are outlined, and a series of tables are presented to facilitate rapid determination of the selection rules for vibrational transitions. Emphasis is placed on the method of nuclear site group analysis in which the number of infrared and Raman active modes of each symmetry may be obtained without detailed analysis of the symmetry elements in the crystallographic unit cell or the construction of tables. By using the tables presented here for most cases identification of the crystallographic space group is sufficient information to allow determination of the vibrational mode selection rules by inspection. Several examples are included in which crystals are analyzed by each of the methods.
Raman intensity de‐enhancement in nontotally symmetric vibrations of copper(II) acetate by forbidden ligand‐field transitions
Authors: Schick G. Alan , Bocian David F.
Published: May 2005

The Raman spectrum of the binuclear transition metal complex copper(II) acetate monohydrate is examined with various excitation wavelengths in the spectral range 17 500 to 25 000 cm−1. Nontotally symmetric vibrations are predominant in the Raman spectrum, and the depolarized Raman bands observed at 320 and 948 cm−1 exhibit marked intensity de‐enhancement as the excitation wavelength approaches the dimer‐associated, Laporte‐forbidden ligand‐field transition at 26 500 cm−1. The intensity de‐enhancement observed for the nontotally symmetric vibrations of copper(II) acetate is in contrast to that observed for other centrosymmetric transition metal complexes studied thus far in which only the totally symmetric vibrations exhibit antiresonance effects. The excitation profiles are calculated for the Raman bands of copper(II) acetate using a model in which the scattering intensity arises from two terms Iα|Be+Bf|2, where Bf couples two charge‐transfer states at 35 000 and 40 000 cm−1 respectively, and Be couples the ligand‐field state to the charge‐transfer state at 35 000 cm−1. The calculated profiles are in good agreement with those observed and predict that the system origin for the ligand‐field transition is located near 21 000 cm−1.
Raman spectra of gases: 23‐Trichloroacetaldehyde
Authors: Durig J. R. , Natter W. J.
Published: May 2005

The Raman spectrum of gaseous trichloroacetaldehyde (chloral) has been recorded from 20 to 3200 cm−1. A series of three transitions (83, 76, 69 cm−1) has been observed for the low frequency torsional mode. The barrier to internal rotation has been calculated to have a value of 1.17 kcal mol−1 (409 cm−1) in the gaseous phase. This value is compared to the corresponding quantity in similar molecules.
Resonance Raman studies of transition metal peroxo complexes: 4‐The potassium μ‐Peroxo‐bis[pentacyanocobaltate(III)], K6[(CN)5CoO2Co(CN)5]·H2O and μ‐superoxo‐bis‐[pentacyanocobaltate(III)], K5[(CN)5CoO2Co(CN)5]·H2O complexes
Authors: Hester R. E. , Nour E. M.
Published: May 2005

Resonance Raman spectra for the peroxide K6[(CN)5CoO2Co(CN)5]·H2O and superoxide K5[(CN)5CoO2Co(CN)5]·H2O complexes have been determined using several different excitation wavelengths. The peroxide spectrum shows a number of strong resonance bands at 141, 174, 408, 602, 804, 1594 and 2369 cm−1 which are assigned to the vibrational modes of the central unit CCoO2CoC (C of the axial CN) as δ(OCoC), δ(CoO2), ν(CoC), ν(CoO), ν(OO), 2ν(OO) and 3ν(OO), respectively. This is confirmed by the measurements of the 18O‐enriched complex. Intensity excitation profiles of these bands demonstrate that the resonance effect is associated with a CT transition of the type O22− ‐Co3+ assigned at 327 nm and that the carbon atoms of the two trans axial cyanides are involved in this electronic transition. The ν(OO) harmonic frequency (ω1) and anharmonicity constant (X11) are shown to be 818 and −7 cm−1, respectively. The superoxide spectrum shows a band at ∼1100 cm−1 assigned to the ν(OO) mode. The resonance effect of this band is shown to be associated with the O2− ‐Co3+ CT transition assigned at 485 nm. For both complexes, plots of [IJcorr]1/2 against the Shorygin function [1+ (νexc/νe)2]/[‐(νexc/νe)2]2 give straight lines from which the value of α′ for OO band in the superoxide is calculated to be twice as big as that in the peroxide complex. This is in agreement with the calculated force constants which show that the superoxide link is ∼1.93 times stronger than the peroxide link, while the CoO is ∼1.4 times weaker in the superoxide complex. Infrared absorption measurements show no bands that are related to ν(OO) or ν (CoO) in either of the complexes.
Etude, par Spectroscopie de Vibration, du Composé 4HNO3·H2O dans les Etats Cristallisé, Vitreux et Liquide Mise en Evidence du Trihydrogénotétranitrate d'Oxonium
Authors: Thi M. Pham , Herzog‐Cance M. H. , Potier A. , Potier J.
Published: May 2005

The IR and Raman spectra of the mixture 4HNO3 · H2O in crystal, glassy and liquid states have been investigated in the frequency range 4000–50 cm−1. The crystal is the oxonium trihydrogentetranitrate where the oxonium ion is practically free (ν(OH) = 3480 and 3385 cm−1). In the trlhydrogentetranitrate ion the charge is not localized. In the glassy and liquid states, four species have been characterized: (1) the oxonium trihydrogentetranitrate; (2) the free molecular association H2O …︁ (HONO2) (νOH(H2O)= 3550 cm−1 and ν OH(HNO3)=2930 cm−1); (3) the free ionic pair (H2OH)+…︁(ONO2)− (ν(OHO)= 2700 cm−1, ν1(NO3−)=1030 cm−1) and (4) free HNO3 molecules (ν(NOH)=926 cm−1).
The Raman band shape and vibrational relaxation of the ν1 mode of SO42− in Na2SO4 and (NH4)2SO4 aqueous solutions
Authors: Fujita Kazuyoshi , Kimura Masao
Published: May 2005

The Raman band of the ν1 vibrational mode of SO42− has been measured in aqueous solutions of Na2SO4 and (NH4)2SO4 at 5–80°C, and analysed from the stochastic point of view. The band shape is approximately symmetric, but cannot be reproduced by a Lorentzian curve. The vibrational relaxation is caused by a random modulation of very low frequency from surrounding water. The vibrational correlation time for the ions is not sufficiently long to make allowance for the Markovian process of relaxation, compared with the correlation time for the bath, that is water. The vibrational correlation function appropriate for these ions is proposed.
Etude Vibrationnelle de trans ‐Dicyano‐4,5 Cyclohexènes: 1—Spectres Raman et IR de Dicyano‐4,5 Cyclohexènes; Spectres Raman de Monocristaux
Authors: Davidovics G. , Gedoux B. , Aycard J. P. , Pourcin J.
Published: May 2005

Comparison of Raman and IR spectra of D0; ‐4,5 D2; ‐3,3,6,6 D4 trans‐4,5 dicyano cyclohexenes and study of polarized Raman spectra of D0 and D4 single crystal varieties allowed to classify in the A and B symmetry classes the 48 normal modes of these molecules specifying those which originate from (HCCN)2 sequence. A conformational effect was found from the dissolved molecules spectra investigation.
Raman spectra of the rare earth orthophosphates
Authors: Begun G. M. , Beall G. W. , Boatner L. A. , Gregor W. J.
Published: May 2005

Raman spectra of anhydrous crystalline samples of all of the lanthanide orthophosphates (with the exception of PmPO4) have been obtained. These data were interpreted in a systematic manner based on the known structures of these compounds. Assignments and correlations have been made for many of the observed bands.
The vibration‐rotation Raman spectrum of P4
Authors: Brassington N. J. , Edwards H. G. M. , Long D. A.
Published: May 2005

The vibration‐rotation Raman spectrum of the ν2 fundamental band of P4 has been recorded photographically using a spectrograph with a reciprocal linear dispersion of 1.36 cm−1 mm−1. Analysis of the spectrum gave the following values for the vibration and rotation constants and the PP bond length: magnified image
The temperature dependence of the low frequency modes in the Raman spectra of ammonium perrhenate and potassium perrhenate
Authors: Korppi‐Tommola J. , Brown R. J. C. , Shurvell H. F. , Sala O.
Published: May 2005

The temperature dependence of the Raman spectrum of potassium perrhenate is reported. Some new detailed results on the temperature dependence of the low frequency Raman bands of ammonium perrhenate are also presented. The frequency versus temperature plots for both internal and external modes of the ReO4− ion in KReO4 appear to be linear over the temperature range from 20 to 300 K. This is in contrast to the non‐linear behaviour of the external modes of the ReO4− ion in NH4ReO4. A crossing of the frequencies of the Ag and Eg librational modes of the ReO4− ion in NH4ReO4 occurs near 200 K, the temperature at which anomolies have been observed in the temperature dependence of several physical properties of this salt. The apparent discontinuities near 200 K in the slopes of the wavenumber versus temperature curves reported earlier1 are now shown to be shoulders on smooth curves. Extrapolation of the frequency versus temperature plots of the Eg and Bg translational modes of the ReO4− ion in KReO4 indicates that a crossing of the curves would occur at about 500 K, while for NH4ReO4 the crossing of the frequencies of these modes is observed near 200 K. The significance of these observations with respect to the structure and a possible higher order phase transition in the NH4ReO4 crystal is discussed.
Composition of a gaseous mixture in chemical equilibrium as studied by Raman spectroscopy: Gas phase acetic acid
Authors: Gaufrès Robert , Maillols Jacques , Tabacik Vlado
Published: May 2005

An experimental method for the determination by Raman spectroscopy of the composition of a gas mixture in which a chemical equilibrium occurs, and the related processing of the data are discussed. Acetic acid vapour, for which none of the components of the equilibrium can be isolated, is chosen as an example. The intensities of the ν(CC) bands are taken as monitors for the concentrations of monomer and dimer species. The mixture has been studied at 120°C and 155°C, in the pressure of c. 0.2–1.5 atm. Using gas density data, a treatment in terms of molal concentrations leads to consistent results, the ratio of Raman scattering cross‐sections at the wavenumbers corresponding to the ν(CC) vibrations (dimer/monomer) being found the same for both isotherms and equal to 1.64. The other significant results are: Kc app = 0.48 atm. at 120°C and 2.67 atm. at 155°C. ΔH (dissociation of one mole of dimer) = 16.3 kcal (range 120–155°C). An alternative treatment in which an ideal behaviour of the gas phase is assumed shows that Raman measurements are accurate enough to emphasize the inadequacy of this approximation in the temperature and pressure range considered. The Raman spectrum of gaseous acetic acid (range 100–3700 cm−1) at ∼220°C and ∼2 atm is presented.
Reorientational dynamics of liquid CH3CCl3 by Raman spectroscopy
Authors: Tsai Nora H. , Baglin Frank G.
Published: May 2005

Spontaneous Raman spectra of the 2940 cm−1 signal of liquid 1,1,1‐trichloroethane (TCE) were studied in order to obtain information concerning the molecular reorientation process. The reorientational correlation time was measured as a function of temperature between 255 and 298K giving an activation energy of 2.6 cal mol−1 for the tumbling motion of neat liquid TCE. Experimental results were compared with those from extended J‐diffusion model, microviscosity theory and previous work. It was found that the TCE molecules underwent small‐step rotational diffusion. The large variation of the reorientational correlation functions and rotational correlation times of TCE in dilute solutions of CCl4, CDCl3 and CD3CN suggested that the dipole moment contribution is an important factor in molecular reorientation in solutions as suggested by Larkin.
Picosecond multichannel Raman spectrometry of solids
Authors: Bridoux M. , Deffontaine A. , Delhaye M. , Rose B. , Silva E. Da
Published: May 2005

A new multichannel Raman spectrometer has been developed and for the first time spontaneous Raman spectra of solids excited by a single laser pulse of 25 ps have been recorded.
Raman linewidth study of molecular complexes of chloroform with ether
Authors: Tanabe Kazutoshi
Published: May 2005

Linewidths of isotropic and anisotropic Raman bands of the CD stretching mode of chloroform‐d have been measured in ether and in carbon tetrachloride, and the hydrogen bonding between chloroform and ether has been investigated from the analysis of the linewidths. Theoretical Raman linewidths due to vibrational and reorientational relaxation have been calculated for two models. One is a non‐hydrogen‐bonded model where a single chloroform molecule is surrounded by ether molecules without forming hydrogen bonds, and the other is a hydrogen‐bonded model where a chloroform‐ether complex as a solute is surrounded by ether molecules. The concentration dependences of experimental Raman linewidths are discussed in relation to these two models.
Raman spectra of ammonium sulphamate single crystal
Authors: Raj A. Sundara , Muthusubramanian P.
Published: May 2005

Raman scattering from single crystals of ammonium sulphamate have been recorded in the region 30–3400 cm−1 with He‐Cd laser excitation. The libratory and translatory modes observed in all the six polarizations were assigned. The assignment of internal modes of ammonium ion indicates minimum distortion of the ion from the tetrahedral symmetry. The presence of medium hydrogen bonding and the range of correlation field splitting are discussed.
Infrared and Raman study of amorphous V2O5
Authors: Sanchez C. , Livage J. , Lucazeau G.
Published: May 2005

Amorphous V2O5 can be obtained by cooling from the melt. This amorphous oxide is very sensitive to water vapour and can even be dissolved in water to give a vanadium pentoxide gel. The hydration process has been followed by infrared and Raman spectroscopy between 20 and 4000 cm−1. Short‐range order in the amorphous oxide appears to be almost the same as in orthorhombic V2O5. The amorphous phase could even be described as made of small crystallites about 100 Å in diameter. The structure of amorphous V2O5 does not seem to be modified by water adsorption, at least during the first stages of the hydration process. However, a drastic modification occurs when enough water is added to give a gel. A general shift to lower frequencies is observed, indicating a weakening of the VO bonds, presumably associated with the formation of new VOH2 bonds. Two different water species have been identified, one of which seems to be almost free of hydrogen bonding. Short‐range order in the gels seems to be quite well defined and the spectra could be interpreted either in terms of crystallites, as in amorphous V2O5, or in terms of molecular (or macromolecular) species containing V2O5, (H2O), groups.
Resonance Raman spectra of short‐lived species of photochromic 2‐ and 4‐(2′,4′‐dinitrobenzyl)pyridine
Authors: Takahashi Hiroaki , Kobayashi Yoko , Kaneko Norio , Igarashi Takashi , Yagi Ichiro
Published: May 2005

Resonance Raman spectra of photo‐activated transient blue species of 2‐(2′,4′‐dinitrobenzyl)pyridine and 4‐(2′,4′‐dinitrobenzyl)pyridine have been measured in methanol solutions using a dual beam pump/probe laser technique and a continuous flow method. Comparison of the Raman spectra with those of N‐methyl derivatives of both compounds and with those of 1‐methyl‐2‐pyridonemethide and dehydrogenated 5‐nitro‐o‐toluic acid indicates that the transient blue species of both compounds take an NH quinoid form and not an aci‐nitro form. The photo‐activated blue species of 4‐(2′,4′‐dinitrobenzyl)pyridine in the molten state is found to be identical with the transient species of the same compound in solution.
Conformation‐dependent Raman bands of phospholipid surfaces. 3—head group Ortho‐phosphate stretching vibrations
Authors: Bicknell‐Brown Ellen , Brown Kenneth G. , Person Willis B.
Published: May 2005

Vibrational frequencies of diethyl phosphate were calculated for rotamers for which the dihedral angle about the PO and CO bonds varied. The frequencies predicted for the symmetric and antisymmetric OPO stretches, the symmetric and antisymmetric ionic PO2− stretches, and the CC stretches are found to be sensitive to the PO and CO dihedral angles. The results of Raman temperature and solvent studies of diethyl phosphate are reported and are found to be in good agreement with the conclusions obtained from the normal coordinate analyses. Frequencies of diethyl phosphate rotamers having the geometries of crystalline glycerophosphorylcholine (GPC), crystalline GPC CdCCl2, and amorphous GPC CdCl2 were calculated and compared to the Raman spectra of these phospholipid head group models. The normal coordinate analyses are in good agreement with Raman spectra. These results indicate that the observed frequencies of phosphate group vibrations may be compared to the normal coordinate analyses of diethyl phosphate rotamers to monitor conformation in phospholipid head groups (and other organic ortho ‐phosphates). The Raman symmetric OPO stretch bandwidth may be used to monitor rotational freedom or broadening due to the distribution of differing conformations.
Raman and infrared studies on new anticancer inorganic ring systems. 1—hexaziridinocyclotriphosphazene N3P3(NC2H4)6
Authors: Manfait Michel , Alix Alain J. P. , Labarre Jean‐François , Sournies François
Published: May 2005

The Raman spectra of the new anticancer agent N3P3(NC2H4)6(MYKO 63), in the solid state and in aqueous solution, and the infrared spectra of the molecule in the solid state, are reported for the first time. All the assignments are discussed in terms of the following vibrations framework (N3P3); ligand (NC2H4); and framework‐Iigand couplings (Nendo2PNexo2). The concept of group frequencies associated with local symmetrical valence coordinates is used extensively.
Two accurate methods to obtain the spectral sensitivity of a Raman spectrometer device
Authors: Ouillon R. , Adam S.
Published: May 2005

We have compared the spectral transmission coefficient of a Raman spectrometer and photomultiplier device determined (a) from a continuous spectrum (calibrated tungsten lamp) and (b) from the spectrum of the rotational Raman lines of D2 molecules. The two methods give a similar sensitivity curve as a function of wavelength. However the first method is more accurate in the determination of the spectral response over a wide spectral range (˜3000 cm−1 or more); and the second method is better than the first for obtaining accurate value of the intensity of the Raman lines and their absolute scattering cross sections.
Structural conclusion on the Schiff base group of retinylidene chromophores in bacteriorhodopsin from characteristic vibrational bands in the resonance Raman spectra of BR570 (all‐trans), BR603 (3‐dehydroretinal) and BR548 (13‐cis)
Authors: Massig G. , Stockburger M. , Gärtner W. , Oesterhelt D. , Towner P.
Published: May 2005

Bacteriorhodopsin the protein of the purple membrane of Halobacteria, involves a retinylidene Schiff base as its photochemically active chromophore. Resonance Raman spectra, which selectively probe the retinylidene Schiff base chromophore, were obtained from aqueous suspensions of the purple membrane. In the unphotolysed chromophore Bacteriorhodopsin, the Schiff base nitrogen carries a proton whose reversible release during a photo‐induced cyclic process is essential for the ability of the purple membrane as a proton pump. It is expected that during this process the Schiff base group undergoes conformational and/or configurational changes, the elucidation of which is important for an understanding of the proton pump mechanism. We have looked for resonance Raman bands characteristic of the terminal group =C14HC15H=NH+‐ of the retinylidene Schiff base chromophore in BR570. Vibrational modes could be assigned on the basis of deuterium exchange at C15 and replacement of the Schiff baèe proton by a deuteron. Resonance Raman spectra of BR603, a chromophore with an additional double bond in the retinal ring (3‐dehydroretinal) but an identical terminal group, were also used for this analysis. Various types of hydrogen bending modes could be identified. From resonance Raman theory it was concluded that the intensities and frequencies of such modes reflect the conformation (bending and twisting angles) of the terminal group. A comparison of the resonance Raman spectra of BR570 (all‐trans) and the 13‐cis component BR548 from the dark‐adapted purple membrane revealed that the conformation of the protonated Schiff base is significantly different in these two chromophores. This is ascribed to variable interactions with the protein. The relation between resonance Raman spectroscopic data and the conformational structure of the terminal group is discussed on the basis of a simple model. From the results of this paper it is suggested that important structural information from resonance Raman spectroscopic data can also be obtained for retinylidene Schiff base chromophores in intermediates of the photochemical cycle.
Variable temperature and pressure Raman spectra of potassium azide KN3
Authors: Khilji M. Y. , Sherman W. F. , Wilkinson G. R.
Published: May 2005

Polarized Raman studies have been carried out on a single crystal of potassium azide as a function of temperature and band assignments have been made. The Raman spectrum of KN3 microcrystalline samples as a function of pressure is reported.
Raman spectra of halogen‐substituted methanes in the liquid state. 2—Band widths of the totally symmetric vibration bands
Authors: Fukushi Kohji , Kimura Masao
Published: May 2005

The isotropic and anisotropic Raman band widths of the totally symmetric vibrations of halogen‐substituted methanes have been measured in the liquid state at room temperature. The isotropic CH and CD stretching vibration bands broaden with increasing molecular weight and this is qualitatively explained by the Fischer‐Laubereau dephasing model. The isotropic band widths of the deformation vibrations are correlated with the reorientational correlation times and are attributed to broadening due to interactions dependent on the orientation, such as the dipole–dipole interaction.
The vibrational spectrum, normal coordinate analysis and conformational equilibrium of 3‐chloro‐2‐methylpropene
Authors: Compton D. A. C. , Hsi S. C. , Mantsch H. H. , Murphy W. F.
Published: May 2005

The infrared spectra of gaseous and liquid 3‐chloro‐2‐methylpropene and the Raman spectra of the compound as gas, liquid and frozen solid have been recorded. Several bands present in the Raman spectrum of the liquid were found to be absent or greatly reduced in intensity in the spectrum of the solid phase, thus indicating the presence of a conformational equilibrium. The Raman polarization data show that the gauche conformer of this compound is the more stable. A study of the temperature dependence of the relative intensities of two Raman bands due to different conformers led to values of ΔHθ of 2.5±0.5 kJ mol−1 and ΔSθ of −4.8±2.0 JK−1 mol−1 for the conformational equilibrium in the liquid phase. These results are consistent with a conformational equilibrium of the type gauche⇌s‐cis, as found for a number of related molecules. A complete vibrational assignment has been proposed for the spectral data, except for the unobserved methyl torsion, aided by a normal coordinate treatment.
The analysis of unresolved Raman excitation profiles. 1—Totally symmetric vibrations with applications to ruthenium red and zirconium trisulfide
Authors: Siebrand Willem , Zgierski Marek Z.
Published: May 2005

The problems involved in the analysis of unresolved Raman excitation profiles are studied theoretically. The aim of such an analysis is to identify vibrational parameters of the resonant state and possibly other states involved in the scattering. For totally symmetric modes, discussed in this paper, the most important of these parameters are the displacements of the equilibrium positions, the problem being to separate these parameters from vibronic line broadening. It is shown how this can be done for systems of several modes and several interfering electronically excited states by model calculations based on a multimode approach. The effect of coupling with solvent modes on vibronic lineshapes is considered explicitly. Some reported analyses based on the independent‐oscillator approach are criticized for their lack of internal consistency or their use of unacceptable parameter values. It is demonstrated that these analyses can be improved by taking multimode effects into account. For cases where the full N‐mode problem is too difficult to handle directly, a method based on interrelated n<N‐mode calculations is developed. Two examples are treated in detail, namely ruthenium red and ZrS3. For both, sets of displacement parameters are derived from the unresolved profiles. A condition for the feasibility of such an analysis is the availability of excitation profiles for all Raman active fundamentals and one or more overtones or combination bands.
New Raman spectroscopic results on the orientational disorder of nitrite anions in sodium nitrite
Authors: von der Lieth Claus Wilhelm , Eysel Hans Hermann
Published: May 2005

Raman spectra of oriented sodium nitrite single crystals are reported. Half‐widths, peak frequencies and band shapes change when the temperature is varied from 30 to 513 K. Resolution of the Raman bands of the symmetric NO vibrations into contributions from ordered and disordered positions yield a temperature‐ dependent order parameter. On the basis of a double minimum potential for the ferroelectric phase, ΔH = 3.5 kJ mol−1 and ΔU = 11.5 kJ mol−1 are calculated from the Raman data.
Raman study of three polytypes of PbI2
Authors: Khilji M. Y. , Sherman W. F. , Wilkinson G. R.
Published: May 2005

Raman spectra of three polytypes of lead iodide (2H, 4H and 6H) have been investigated as a function of temperature at ambient pressure. The band assignments have been carried out on the basis of folding of 2HPbI2 phonon dispersion curves in the Brillouin zone. The temperature induced changes in the Raman spectra are interpreted in terms of an interpolytypic phase transformation (at 415 K) and photodecomposition at 470 K.
Raman spectra of disordered Hg(NH3)2Cl2 and Hg(NH3)2Br2
Authors: Ebisuzaki Y. , Hobbs C. C. , Richard P. D.
Published: May 2005

The Raman spectra of disordered Hg(NH3)2Cl2, Hg(ND3)2Cl2 and Hg(NH3)2Br2 are reported. The spectra consist of the internal vibrations of the mercuric complex with no lattice phonons being observed. The bending and the symmetric stretching mode for the complex (Hg(NH3)) occur at 110 cm−1 and 413 cm−1 in the chloride and at 85 cm−1 and 381 cm−1 in the bromide.
Bond polarizability calculations of the Raman optical activity of (R)‐(+)‐3‐Methylcyclohexanone
Authors: Barron L. D. , Clark B. P.
Published: May 2005

The bond polarizability theory of Raman optical activity is used to calculate the complete Raman optical activity spectrum of (R)‐(+)‐3‐methylcyclohexanone. The results are compared with the observed depolarized Raman circular intensity difference spectrum in the region 50‐1800 cm−1. The predictions are better in the upper half of this range probably because at lower frequency the calculated normal coordinates are less reliable and the contributions from carbonyl deformations increase.
Dispersion curves of an infinite polyene chain (Erratum)
Authors: Tasumi M.
Published: May 2005

This Erratum corrects a mistake relating to the definition of force constants which appeared in the following paper: F. Inagaki, M. Tasumi and T. Miyazawa, Vibrational analysis of Polyene Chains, J. Raman Spectrosc. 3,335 (1975).
Raman spectra of the rare earth trimetaphosphates
Authors: Begun G. M. , Bamberger C. E.
Published: May 2005

Raman spectra of anhydrous crystalline powders of all the lanthanide trimetaphosphates (with the exception of Pm(PO3)3) and of yttrium trimetaphosphate have been obtained. These data have been interpreted in a systematic manner based on the known structures of these compounds. Variations of the vibrational band frequencies with atomic number are much less than with the orthophosphates.
Raman spectra of pyridine N‐oxide complexes with Co(II) and Ni(II) perchlorates
Authors: Arenas J. F. , Marcos J. I. , Otero J. C.
Published: May 2005

The complexes [(PyO)6Co](ClO4)2 and [(PyO)6Ni](ClO4)2 have been synthesized and their Raman spectra recorded from a microcrystalline powder. The experimental data agree with those previously calculated for the low frequency vibrations. General assignments of both spectra have been proposed on the basis of a group factor S6 for both the cation and the anion.
In vivo studies of nucleic acid by ultraviolet resonance Raman spectroscopy on eucaryotic living cells
Authors: Nocentini S. , Chinsky L.
Published: May 2005

We observe for the first time spectra of nucleic acids of living cells, obtained by resonance Raman spectroscopy excited in the u.v. range (257 nm). This wavelength which is close to that of the maximum of absorption of the main components of nucleic acids allows the resonance Raman effect to be obtained and the fluorescent contribution of aromatic amino acids present in proteins to be avoided.
Vibrational spectra of bromocyclopropane
Authors: Wurrey C. J. , Berry R. J. , Yeh Y. Y. , Little T. S. , Kalasinsky V. F.
Published: May 2005

Fourier transform infrared spectra of bromocyclopropane at a resolution of 0.5 cm−1 have been recorded as well as liquid phase infrared spectra of this molecule from 4000–400 cm−1. For the first time, gas phase Raman spectra and solid phase infrared spectra of bromocyclopropane have been obtained. By combining all of the spectral data available it has been possible to assign all 21 normal modes of vibration of bromocyclopropane (as well as several overtones and combination bands) with a high degree of confidence. This proposed assignment is in excellent agreement with assignments for similar molecules and with anticipated cyclopropyl group frequencies.
Raman and infrared spectra of solid carbon diselenide
Authors: Torrie B. H. , Andrews B. , Anderson A. , Powell B. M.
Published: May 2005

Raman and infrared spectra of polycrystalline samples of CSe2 have been recorded at temperatures from 20–205 K. A comparison with previous results for CS2 shows that the spectra are consistent with the two substances having the same centrosymmetric orthorhombic structure. The observed spectra for CSe2, in both the lattice and molecular regions, are in good agreement with group theoretical predictions based on this structure. There is only one solid phase over the range of temperatures examined.
The Raman spectra of manganese and zinc fluorotitanate hexahydrate systems
Authors: Choudhury P. , Ghosh B. , Raghuvanshi G. S. , Bist H. D.
Published: May 2005

Raman spectra of ZnTiF6, 6H2O and MnTiF6, 6H2O single crystals have been observed in different polarizations. The various mode frequencies have been identified by studying the spectra in solution and comparing our data with those on similar systems.
Raman spectra of 1‐organosilatranes
Authors: Imbenotte M. , Palavit G. , Legrand P.
Published: May 2005

The Raman spectra of five organosilatranes (R = H, CH3, (CH2)3NH2, OC2H5 and F) are reported. The normal modes of the cage are presented and the assignment of the Si‐N stretching mode is discussed on the basis of C3ν symmetry for the silatrane skeleton.
Vibrational spectroscopic studies of a new class of oligophosphate glasses of biological interest: Part 2
Authors: Bertoluzza A. , Battaglia M. A. , Simoni R. , Long D. A.
Published: May 2005

Examples of a class of glassy biomaterials with chemical composition similar to that of bone have been prepared by heating mixtures of calcium metaphosphate and hydroxylapatite. The Raman and infrared spectra of these materials are reported and discussed in relation to glass structure, which is of the linear polymeric type with chain length depending on the molar ratio R=[CaO]/[P2O5]. The products of the thermal decomposition of hydroxylapatite have also been characterized spectroscopically.