bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular interactions between electrophiles and nucleic acids. II—Raman and infrared spectra of adenine, adenine hydrochloride and the corresponding 1‐methyl derivatives in relation to tautomerism and mutagenic phenomena of bases of nucleic acids
Authors: Bertoluzza A. , Fagnano C. , Tosi R. , Morelli M. A. , Long D. A. 
Published: May 2005

AbstractThe Raman and IR spectra of adenine (AH3) and of its derivatives adenine hydrochloride (AH4Cl), 1‐methyladenine (1MeAH2) and 1‐methyladenine hydrochloride (1MeAH3Cl) are discussed in relation to the mutagenic and carcinogenic activities that they display.The spectra give evidence for a shift of tautomeric stability from the aminic form, which is favoured in AH3, toward the iminic, or iminic‐derived form, in the derivatives AH4Cl, 1MeAH2 and 1MeAH3Cl.The different biological activities of this series of compounds, in particular the mutagenic and carcinogenic effects, can be interpreted in terms of different reactivites associated with the π electronic systems, and of a hydrogen‐bond coupling different from the canonical Watson–Crick type.
Raman and far‐infrared spectra of crystalline methylene bromide
Authors: Anderson A. , Torrie B. H. , Danagher D. J. , Laurin D. G. , White J. K. , Zung W. W. E. 
Published: May 2005

AbstractLattice vibrations of polycrystalline CH2Br2 and CD2Br2, obtained by Raman and far‐infrared spectroscopy, are reported. The observed peaks are compared with the predictions of a group theoretical analysis based on the known structure of the stable phase. Assignments are proposed on the basis of isotopic shifts and intensities. Evidence of a metastable phase is presented, but attempts to isolate this phase at low temperatures were unsuccessful.
Micro‐Raman study of barium sulphate coprecipitated with potassium ions
Authors: Haley L. V. , Mattioli T. A. , Wiles D. R. 
Published: May 2005

AbstractResults of a micro‐Raman spectral investigation of K+‐doped BaSO4 crystals prepared by a previously described radiochemical coprecipitation procedure are reported. Changes in the spectral bands of the ν1, ν2, ν3 and ν4 modes of the sulphate ion as a function of K+ concentration in the BaSO4 crystals reflect changes in the local environment of the SO42− ion indicating mixed‐crystal formation. These preliminary results show that Raman spectroscopy can be used to characterize changes in the BaSO4 lattice due to coprecipitated impurities.
Intensités Raman et Attribution des Modes dans le Poly(Fluorure de Vinylidène) en Phase β
Authors: Armengaud Alain , Ramonja Jean‐Louis , Abenoza Michel 
Published: May 2005

AbstractLa comparaison des intensités théoriques et des intensités expérimentales, réalisée sur la forme β du poly(fluorure de vinylidéne) orientée monoaxialement nous a permis d'attribuer les raies Raman observées aux différents modes de vibration de la chaǐne. Nous précisons plus particulièrement l'attribution des raies de fréquences 1278, 882 et 840 cm−1 (raies qui subissent une profonde modification lors de la transition ferro–paraélectrique des copolymères contenant du PVF2β) aux mouvements νs(CC), ρ(CH2) et νs(CF2), respectivement. Enfin, nos résultats vérifient que les groupements CH2 et CF2 conservent une bonne individualité dans la chaǐne du polymère.
Bond polarizability anisotropy: Resolution of the sign ambiguity
Authors: Armstrong Robert S. , Aroney Manuel J. , Clark Robin J. H. 
Published: May 2005

AbstractAn internally consistent “valence–optical” scheme of additive bond and group polarizabilities, obtained from analysis of electric birefringence, refractivity and Raman intensity data, is shown to apply to a series of compounds of Group IVB elements. For all M‐halogen bonds considered (M = Si, Ge or Sn; halogen = C1, Br or I), only the positive option for ±γ, the bond anisotropy from Raman intensities, is compatible with the scheme. The negative alternatives for γ lead to results which are anomalous and in some instances not physically meaningful. This procedure permits a definitive resolution of the problem of the sign ambiguity in ±γM‐halogen.
Crystal growth and Raman spectra of CaHCl and CaDCl
Authors: Ayadi Mohamed , Sieskind Manuel 
Published: May 2005

AbstractThe Raman spectra of CaHCl and CaDCl were measured at room temperature. The symmetries of the modes were determined by means of polarized Raman scattering from oriented single crystals and by deuterium substitution of the hydrogen atoms.
Ultraviolet (239 nm) resonance Raman spectroscopy of an enzyme–substrate intermediate of papain
Authors: Bajdor K. , Peticolas W. L. , Wharton C. W. , Hester R. E. 
Published: May 2005

AbstractA new technique is described for the study of intermediates formed in enzyme–substrate complexes by resonance Raman spectroscopy. This technique uses an ultraviolet line from a YAG laser which is obtained by frequency doubling to 266 nm and then shifting by means of stimulated anti‐Stokes Raman scattering to 239 nm. The advantage of this line is that it falls in an absorption minimum for the aromatic residues, tyrosine and tryptophan, which permits the observation of resonance Raman spectrum of enzyme‐substrate intermediates whose absorption maxima fall within the range 225–245 nm. In order not to decompose the sample and yet conserve it, a slow flow technique has been devised which avoids the use of a quartz window. The method is illustrated with the complex formed from a simple oligopeptide and the enzyme papain. Excellent ultraviolet resonance Raman spectra are obtained from the enzyme, the substrate and the complex. By computer subtraction of the component spectra from the spectra of the complex, the presence of a new band at 1680 cm−1 is seen, which is ascribed to the carbonyl band of the acyl group bound at the active site.
Semibullvalène: Spectres de Vibration et Leur Analyse
Authors: Tabacik Vlado , Blaise Paul 
Published: May 2005

AbstractLe tricyclo[3.3.0.02,8]octadiène‐3,6 (semibullvalène; C8H8) siège d'un réarrangement de Cope intramoléculaire, présente un potentiel à double minimum. Sont enregistrés ses spectres Raman (1) et infra‐rouge (1 et g). 41 fondamentales parmis 42 ont été identifiées et leur attribution proposée. Cette attribution est basée sur la détermination des facteurs de dépolarisation ρp et sur I'analyses des contours rotationnels des bandes en absorption infra‐rouge. Une attention particulière est accordée aux doublets présents dans les spectres.
Crystal standard/metal disc method for the measurement of low‐temperature resonance Raman spectra in the solid state
Authors: Bartholomew C. R. , McConnell A. A. , Smith W. E. 
Published: May 2005

AbstractMounting a sodium nitrate crystal on the surface of a disc made by compacting silver powder and the material to be studied enables Raman spectra of compounds such as zinc and nickel phthalocyanine to be measured in such a way that relative peak inteasities in any one disc can be quantified using the nitrate as a standard. It is a good method for the measurement of low‐temperature spectra of resonant compounds and for the measurement of temperature dependence.
A new multichannel Raman optical activity instrument
Authors: Barron L. D. , Torrance J. F. , Cutler D. J. 
Published: May 2005

AbstractA fully computer‐controlled Raman optical activity spectrometer equipped with an intensified diode array detector is described. Despite using a conventional single‐lens light collection system for simplicity, both polarized and depolarized Raman optical activity spectra can be obtained rapidly and routinely. A novel double grating spectrograph design permits good spectra to be obtained down to 50 cm−1 in liquids. Natural spectra of the chiral samples (–)‐α‐pinene and (+)‐methylcyclohexanone and magnetic spectra of iridium (IV) hexachloride are presented.
Correlation of the Raman ν1 bands of aquated divalent metal ions with the cation–hydrated water distance
Authors: Kanno H. 
Published: May 2005

AbstractThe frequencies of the symmetric stretching ν1 Raman bands have been measured for aquated Be2+, Mg2+, Ca2+, Mn2+, Fe2+, Ni2+, Zn2+, Cd2+, Hg2+ and Pb2+ ions in aqueous solutions. There is a linear relationship between the frequency of the band and 1/rMO, where rMO is the distance between a metal cation and its hydrated water molecules. It is concluded that the electrostatic theory for ionic hydration can explain most of the hydrations of divalent metal ions in aqueous electrolyte solutions.
Programme d'Identification Moléculaire Informatisée à Partir de Spectres Raman. Exemples d'Inclusions Fluides dans les Minéraux
Authors: Benosman A. , Vergoten G. , Moschetto Y. , Fleury G. 
Published: May 2005

AbstractA l'image des interpréteurs PAIRS (spectroscopie infrarouge) et PARS (spectroscopie Raman) pour des fonctions organiques, un troisième interpréteur PARSM a été élaboré. Cet interpréteur sert à la reconnaissance de fonctions chimiques et minéralogiques souvent rencontrées dans I'étude des inclusions fluides. Après une petit aperçu sur l'importance de la spectroscopie Raman pour l'étude des inclusions fluides, nous décrivons la démarche utilisée pour la mise au point de PARSM.
Raman scattering temperature measurements for water vapor in non‐equilibrium dispersed two‐phase flow
Authors: Neti S. , Anastasia C. M. , Smith W. R. , Chen J. C. 
Published: May 2005

AbstractLaser Raman spectroscopy has been demonstrated to be a useful technique for making temperature measurements in single‐phase water vapor at atomospheric pressure over the temperature range 393–593 K. It has also been demonstrated that laser Raman spectroscopy can measure water vapor temperatures in non‐equilibrium dispersed two‐phase flow over the temperature range 393‐353 K in spite of large Rayleigh and Mie scattering from droplets. Estimated temperature uncertainties are ±15 K for single‐phase and ±22 K for two‐phase flows.
FT‐IR, photoacoustic and micro‐Raman spectra of the dodecacarbonyltriruthenium (O) complexes Ru3(13CO)12 and Ru3(CO)12
Authors: Butler Ian S. , Xu Zhen H. , Darensbourg Donald J. , Pala Magdalena 
Published: May 2005

AbstractRoom‐temperature FT‐IR, photoacoustic and micro‐Raman spectra are reported for the fundamental and binary ν(CO) overtone and combination regions of solid Ru3(13CO)12(13C‐enriched 99.98%) and Ru3(CO)12. These results, together with solution FT‐IR data, have enabled some vibrational assignments to be made.
Computer‐controlled system for the accurate measurement of depolarization ratios
Authors: Steele D. , Stevens Josephine A. , Gerrard D. L. , Maddams W. F. 
Published: May 2005

AbstractA computer‐controlled switching device for a Pockel cell is described. Depolarization ratios of Raman bands are measured accurately as the intensities of alternate polarizations are recorded at a time separation equal to that for a single point measurement. Measurements on liquid chloroform agree to within experimental reproducibility with literature values.
Raman spectro‐electrochemistry. I. In situ raman spectroscopic studies of the electrochemical reduction of CO2 at lead‐impregnated PTFE‐bonded carbon gas diffusion electrodes
Authors: Masheder D. , Williams K. P. J. 
Published: May 2005

AbstractIn situ Raman spectroscopic studies of the electrochemical reduction of carbon dioxide at lead‐impregnated PTFE‐bonded carbon gas diffusion electrodes are reported. Polarization of the electrode surface resulted in the appearance of two weak bands at 2824 and 2915 cm−1. These do not correspond to the wavenumber shifts expected for free formic acid, but they are thought to arise from the presence of a ‘free’ formate ion and the formic acid perturbed at the electrode surface, respectively. Spectral changes observed at lower wavenumber shifts on polarization of the electrodes are interpreted in terms of the reduction of lead oxide to lead.
Raman study of molecular motions in relation to phase transitions in [Ni(NH3)6](NO3)2
Authors: Janik J. M. , Janik J. A. , Pick R. M. , Le Postollec M. 
Published: May 2005

AbstractA Raman band at 710 cm−1 has been used for the study of the NO3− ion reorientation and of the phase transitions in [Ni(NH3)6](NO3)2. The strong temperature dependence of the width of this band in phase I is evidence for the NO3− reorientation in this phase. The reorientations stops in phase II. The same band was used for studying the phase II/phase III transition. The large thermal hysteresis of this transition has been confirmed.
Reorientation of methylbenzene molecules in the liquid phase: A comparative Raman band shape analysis
Authors: Ribeiro‐Claro P. J. A. , Da Costa A. M. Amorim , Teixerira‐Dias J. J. C. 
Published: May 2005

AbstractA comparative Raman band shape study of the reorientation of monosubstituted benzene molecules (C6H5X, X = CH3, CH2Cl, CHCl2, CCl3 and CCCH3) in the liquid phase has been performed. Reorientational correlation functions appear to be less sensitive to molecular reorientation about the major axis (Z axis) than to rotation of the axis itself, approaching a symmetric top case. Molecular motion anisotropy is found to increase in the order C6H5CH3 < C6H5CH2Cl < C6H5CHCl2 < C6H5CCl3 < C6H5CCCH3 as the rotation about the Z axis becomes increasingly preferred. These results are in agreement with NMR spin–lattice relaxation data.As expected for liquids with imporatant intermolecular interactions, both the free rotor and Kubo's model fail to fit the experimental correlation functions.
Spectres Raman de l'Ethylene‐d0 et de l'Ethylene‐d4 en Phase Gazeuse. 2—Spectres Raman de Rotation Pure. Evolution du Rapport R = αb/αa en Fonction de la Deutération de l'Ethylène
Authors: Barbès H. 
Published: May 2005

AbstractLes spectres de rotation pure de C2H4 et de C2D4 ont été enregistrés. La reproduction des contours expérimentaux par des spectres simulés permet d'évaluer le rapport R égal à 0.21 pour C2H4 et 0.23 pour C2D4. Les valeurs des polarisabilités optiques principales, et les relations de αzz, αyy, αxx et R en fonction des polarisabilités de liaison de l'éthylène permettent de montrer l'évolution croissante de R avec la deutération.
Coexistence of intermolecular couplings and Fermi resonance in the liquid phase
Authors: Sokolowska Anna 
Published: May 2005

AbstractThe positions of polarized Roman bands resulting from simultaneous Fermi resonance and intermolecular couplings were calculated by a perturbation method. It was found that four bands should be observed, two in the isotropic and two in the anisotropic component. The dependence of the band positions on the positions of the unperturbed bands and on the intermolecular coupling constants and also the dependence of band intensity rations on the intermolecular coupling constant were investigated. The intermolecular coupling constants, the Fermi resonance coupling constants and the unperturbed band positions of ethylene carbonate were calculated from the derived equations and the experimental data.
Electronic Raman and fluorescence spectroscopic studies of Eu3+‐doped A2SO4 · χH2O sulphates
Authors: Ram Shanker 
Published: May 2005

AbstractIR, Raman (100–6000 cm−1), visible absorption and fluorescence spectra of Eu2(SO4)3 · 8H2O and that doped in A2SO4 · χH2O (with A = Li, Na, K, Rb or Cs) have been studied. The bands observed are analysed in terms of the internal and external vibration modes due to the SO and H2O groups and the Eu3+ electronic Raman transitions. Particular attention is given to the electronic Raman transitions for all the 7F0 → 7FJ′ (J′=1–6) levels in an Eu3+ (4f6) configuration. In this regard, several spectra at different temperatures (77–500 K for solids and 77–360 K for solutions) and concentrations (for solutions) were measured with different lines of an Ar+ laser. This automatically isolates and thus helps in the identification of the bands with different vibrational/electronic Raman, fluorescence or vibronic origins. The bands of H2O are also confirmed by deuteriation. The electronic Raman bands are too weak and in general are masked in the fluorescence. Addition of a few drops of KI in an aqueous solution has been found to depress the intensity for the fluorescence and as a result it facilitates the observation of the electronic Raman effect. The transition energies as observed for the various 7F0 → 7FJ′ Raman bands are consistent with those deduced by the 5D0.1 → 7FJ′ fluorescence and 7F0 → 7FJ′ IR absorptions. The transitions in the Raman and fluorescence processes seem to be inter‐related. The specimens containing the alkali metal cations or the deuteriated salts reveal very intense fluorescence, and only a few and weak Raman bands. The interstate coupling and vibronic decay of the Eu3+ ions through the several radiative and non‐radiative processes operative are generally responsible for these features.
Polarized Raman and IR spectra of lattice vibrations in the non‐centrosymmetric m‐aminophenol crystal
Authors: Giermanska J. , Szostak M. M. , Girard A. , Sanquer M. 
Published: May 2005

AbstractPolarized Raman and IR spectra of lattice vibrations (10–260 cm−1) in the m‐aminophenol crystal have been recorded at various temperatures in the range 20–300 K. LO–TO splittings of about 2 cm−1 have been observed for two modes of A1 symmetry. Lattice dynamic calculations of frequencies and calculations of Raman intensities based on the generalized oriented gas model have been performed. A discussion of the influence of hydrogen bonding on the lattice dynamics is presented.
Raman resonance excitation profile of the μ‐oxobis[pentacyanomanganate (III)] ion
Authors: Jubert A. H. , Varetti E. L. , Nakamoto K. , Sala O. , Aymonino P. J. 
Published: May 2005

AbstractThe resonance Raman spectra of potassium μ‐oxobis[pentacyanomanganate(III)] cyanide, K7[Mn2O(CN)10]CN, were measured using exciting lines at 356.4, 406.7, 530.9, 568.2, 603.5, 647.1 and 676.4 nm. By combining these data with those obtained previously (excitations at 457.9, 476.5, 488.0, 496.5, 514.5 and 608.6 nm), the excitation profiles were plotted for three totally symmetric vibrations at 1880 (CNax strech), 527 (MnCax stretch) and 259 cm−1 (MnOMn stretch). It was found that the equation derived by Mingardi et al. can adequately express these excitation profiles and that the previous assignment of the electronic transition at 509 nm needs revision.
Investigation of SnCl2AlCl3 mixtures by Raman spectroscopy
Authors: Gilbert B. P. , Taulelle F. , Trémillon B. 
Published: May 2005

AbstractRaman spectra of the liquid and gas phases are reported for various molten mixtures of SnCl2 and AlCl3. As in other chloroaluminate melts, AlCl4− and Al2Cl7− are the main species present in the liquid phase. However, the spectra indicate the presence of Al2Cl6; in addition, the splitting of the ν3 band and the location of the ν1 band (341 cm−1) observed for AlCl4−, are in favour of a strong Sn2+‐AlCl4− interaction. A quantitative study of the main ν1 band ratios in the liquid allows an estimation of the equilibria between the three above‐mentioned species and, consequently, the calculation of the activity of Al2Cl6. By following the intnsity of the ν2 Al2Cl6 band in the gas phase, a method for measuring the Al2Cl6 pressure has been developed. Because a phase separation occurs around 87% of Alcl3, Raoult's law has been reformulated and the Al2Cl6 activities measured from the liquid and gas phases are in very good agreement. A comparison of the acidity level with other chloroaluminate melts is also made.
Raman spectra of some indo‐, thia‐ and selena‐carbocyanine dyes
Authors: Sato Hiroyasu , Kawasaki Masahiro , Kasatani Kazuo , Katsumata Masa‐aki 
Published: May 2005

AbstractRaman spectra of some indo‐, thia‐ and selena‐carbocyanine dyes have been measured. The bands are assigned to the modes associated with the methine chain, end chromophore and methyl/ethyl group based on a comparison of the positions of the bands for a series of dyes with similar structures and those for 1,2,3,3–tetramethylindoleniumiodide and 2–methyl–3–ethylbenzothiazolium iodide, compounds related to the end chromophore of indo‐ and thia‐carbocyanine dyes, respectively.
UV resonance Raman study of the DNA–β‐propiolactone interaction
Authors: Jollès Béatrice , Chinsky Laurent , Laigle Alain 
Published: May 2005

AbstractThe interaction between DNA and a carcinogenic molecule, β‐propiolactone (BPL), has been followed by UV resonance Raman spectroscopy. The excitation wavelength, 257 nm, is such that the information obtained concerns the changes in the nucleic bases. At the same time as the spontaneous pH decrease caused by the hydrolysis of some BPL molecules, alkylation at N‐7 of guanine is shown to occur. More sites of interaction are found after the enzymatic hydrolysis of DNA modified by BPL at neutral pH. Guanine is shown to be modified at several sites: N‐7, N‐2 and N‐1. Alterations of adenine are also found, in N‐1 and after a reorganization of the structure concerning the N‐1 and N‐6 positions.
High‐pressure Raman study of ammonium halides
Authors: Jeon Seung‐Joon , Porter Richard F. , Ruoff Arthur L. 
Published: May 2005

AbstractRaman spectra of NH4X (X = Cl, Br, I) in the range 2800–3200 cm−1 have been obtained at pressures up to 40 GPa at room temperature. The pressure dependences of the n̈1 and n̈3 modes are discussed in relation to hydrogen bonding effects in the crystals. The Raman spectra of ammonium halides show that the n̈3 mode merges to the v1 mode at pressures above 22.5 GPa in NH4Cl, 33.5 GPa in NH4Br and 35 GPa in NH4I.
Spectroscopic and molecular orbital studies of ethyl chloroactate and ethyl bromoacetate
Authors: Dube N. , Porwal P. , Prasad R. 
Published: May 2005

AbstractInfrared spectra of ethyl chloroacetate and ethyl bromoacetate in the region 4000‐600 cm−1 have been recorded, together with laser Raman spectra of the molecules in the region 4000–100 cm−1. These spectra, in conjunction with CNDO 2 computations, were employed to study the conformational behaviour of the molecules. A normal coordinate analysis was carried out for the cis‐trans isomers of these molecules and supported the frequency assignments fairly well.
UV resonance Raman study of platinum binding to guanine in mono‐ and di‐nucleotides
Authors: Perno Joseph R. , Park Young D. , Reedijk Jan , Spiro Thomas G. 
Published: May 2005

AbstractUltraviolet resonance Raman UVRR spectra, with 240 and 218 nm excitation, are reported for complexes of cis‐NH32Pt2+ with dGMP 2‐deoxyguanosine 5′‐monophosphate having H or D at C‐8. Previously reported UVRR effects of Pt binding to G are confirmed and extended. Excitation profiles recorded throughout the UV region are reported, together with cross‐sections for the perchlorate ion, used as an internal standard. The excitation profiles show strong losses in enhancement associated with Pt binding for most of the guanine G UVRR bands in resonance with the UV electronic transitions of G. Hypochromic effects are involved, associated with diminished transition dipole moments due to the N‐7‐bound Pt, as are changes in Franck‐Condon products. A new, weak resonance is seen in the excitation profiles at ca 220 nm, and is attributed to a Pt → G metal‐ligand chargetransfer transition. Because bands showing large frequency shifts on Pt binding are selectively enhanced by this transition, 218 nm is the best wavelength for monitoring Pt binding to G in UVRR spectra. Even at this wavelength, Raman contributions from uncomplexed G and also A tend to obscure the Pt‐bound G spectrum, as shown by the spectra of the dinucleotides d(GpG) and d(ApG) complexed with Pt(dien)2+ (dien = diethylenetriamine), although a marker for Pt‐bound G can still be detected. The 218 nm‐excited spectrum of cis‐Pt[d(GpG)N‐7(1), N‐7(2)] shows clear evidence of both N(C‐3′‐endo) and S(C‐2′‐endo) sugar conformations, and also intensity alterations which may be associated with the ‘head‐to‐head’ arrangement of the Pt‐bound G residues.