bluuebunny/crossref_metadata_2025 huggingface dataset:
Raman and far‐infrared study of the lattice vibrations of methyl cyanide
Authors: Anderson A. , Zeng W. Y.
Published: May 2005

Low‐frequency Raman and far‐infrared spectra of both solid phases of CH3CN and CD3CN at temperatures between 20 K and the melting point have been recorded. Assignment of the observed peaks as librations about the principal molecular axes or as translational modes is facilitated by finding the frequency ratios of corresponding peaks for CH3CN and CD3CN. The spectra are compared with group theoretical predictions, based on possible space groups for each of the two phases. It is found that a unit cell with point group C2h and four molecules on general sites is favoured for phase I. The lattice spectra do not appear to be compatible with the larger unit cell proposed for phase II.
Raman and infrared spectra of trichloromethanesulphenyl chloride (CCl3SCl)
Authors: Védova C. O. Della , Aymonino P. J.
Published: May 2005

The infrared and Raman spectra of CCL3SCl have been thoroughly investigated and as results a complete assignment of bands and point group C1 for the molecule are proposed.
Molecular interactions between electrophiles and nucleic acids. I—Raman spectroscopic study of the molecular reactivity of three typical methylating agents
Authors: Bertoluzza A. , Fagnano C. , Morelli M. A. , Tosi R.
Published: May 2005

Three methylating agents with different carcinogenic powers, dimethyl sulphate [(CH3O)2SO2 (DMS)], methyl methanesulphonate [CH3SO2OCH3 (MMS)] and N‐methyl‐N‐methyl‐N‐nitrosourea [CH3N(NO)CONH2 (MNU)], were studied by Raman spectroscopy in order to identify the reactive species which are formed in buffered aqueous solution at neutral pH.

In all cases, the formation of methanol was observed. By hydrolysis DMS produces CH3OSO3−, and H3O+ ions, and MMS produces CH3SO3− and H3O+ ions. In the case of MNU the reaction is more complex and proceeds with gaseous products to give methanol quantitatively.

This investigation is a preliminary to the study of molecular interactions between the three methylating agents and nucleic acid components.
Resonance Raman investigation of iodine and bromine adsorbed on porous vycor glass
Authors: Favre Pierre , Jayasooriya Upali A. , Powell Donald B.
Published: May 2005

Resonance Raman spectra have been recorded for bromine and iodine supported on the surface of porous Vycor glass. They show that the halogens are mainly physisorbed on the Vycor glass. Other features indicate the presence of polyhalide species of type X3−. When the amount of polyhalide is large, we observe peaks which can be attributed to a halogen molecule coordinated to a Lewis base, which is probably X3−.
Use of time‐resolved Raman spectroscopy for measuring mixing times and concentrations
Authors: Cook B. W. , Louden J. D. , Lorriaux‐Rubbens A. , De Kerangue L. Nouël , Bridoux M. , Wallart F.
Published: May 2005

Time‐resolved Raman spectroscopy (TRRS) is presented as a non‐invasive technique for measuring mixing/concentration profiles in a fully baffled disc turbine‐agitated tank.
Surface‐enhanced Raman scattering (SERS) of aromatic amino acids and their glycyl dipeptides in silver sol
Authors: Kim Sang Kyu , Kim Myung Soo , Suh Se Won
Published: May 2005

The surface‐enhanced Raman (SER) spectra of aromatic amino acids (L‐phenylalanine, L‐tyrosine and tryptophan) and their glycyl dipeptides (glycyl‐L‐phenylalanine, glycyl‐L‐tyrosine and glycyl‐L‐tryptophan) adsorbed on Ag colloidal particles have been obtained. The surface‐enhanced and ordinary Raman spectra show satisfactory correlations. The most prominent features in the SER spectra of all compounds are the strongly enhanced peaks at about 930 and 1390 cm−1 due to the CCOO− stretching and COO− symmetric stretching vibrational modes, respectively. This is interpreted as suggesting that the above compounds are adsorbed on the Ag surface through the carboxylate group. In the SER spectrum of glycyl‐L‐phenylalanine, the amide I and II bands are observed at about 1670 and 1520 cm−1, respectively.
Vibrational spectra of and phase transitions in caesium hydrogen sulphate
Authors: Pham‐Thi M. , Colomban Ph. , Novak A. , Blinc R.
Published: May 2005

The Raman and infrared spectra of the superionic protonic conductor CsHSO4(CsDSO4) were investigated in the 18–450 K range. Polarized single crystal Raman and infrared reflection spectra were also studied at room temperature. An assignment of bands due to internal and external vibrations is given in terms of symmetry species and approximate type of motion. The spectroscopic results, in particular the behaviour of the Raman bands as a function of temperature, are used to discuss the crystalline structures of various phases, hydrogen bonding, the type and degree of structural disorder, phase transitions and conductivity.
Resonance Raman studies of guanine derivatives
Authors: Chinsky L. , Jollès B. , Laigle A. , Turpin P. Y.
Published: May 2005

Ultraviolet resonance Raman spectra of some guanine derivatives in aqueous solutions are reported, viz. guanosine, N1 ‐methylguanosine, N2 ‐methylguanosine and N2, N2 ‐dimethylguanosine. The effects of deuteriation were also investigated. The vibrational patterns of guanosine and the derivatives are complicated, since they involve contributions from both the pyrimidine and imidazole rings. However, the understanding of the spectral features is of special interest since some bands are highly sensitive to the B to Z conformational transition of alternating dG‐dC sequences containing DNA. From these UV resonance Raman spectra, assignments of the principal modes of vibration are proposed and discussed in relation to the results of normal coordinate calculations previously performed by other workers.
Raman and far‐infrared spectra of crystalline methylene iodide
Authors: Torrie B. H. , Anderson A. , Andrews B. , Laurin D. G. , White J. K. , Zung W. W. E.
Published: May 2005

The lattice vibrations and internal modes of polycrystalline CH2I2 and CD2I2 have been studied as a function of temperature using Raman and far‐infrared spectroscopy. CH2I2 has two stable phases, one of which is metastable in the temperature range of the other, and a second metastable phase. CD2I2 has only one solid phase. Possible structures for the various phases are discussed.
Polarization measurements in Raman microspectroscopy. I—Isotropic samples
Authors: Brémard Claude , Laureyns Jacky , Merlin Jean‐Claude , Turrell George
Published: May 2005

A quantitative analysis is made of the problem of obtaining accurate polarization measurements in Raman microspectroscopy. The introduction of experimentally determined correction factors arising from the optical properties of the beam splitter allows the depolarization by the microscope objective to be studied separately. Correction curves are calculated for the various parameters which characterize the light‐excitation path and the light‐collection path. These parameters are functions of both the numerical aperture of the objective and the refractive index of the (isotropic) sample. The introduction of these parameters into the expressions for the depolarization ratios of various Raman and resonance Raman bands accounts well for the differences noted between the results of the present microprobe measurements and those obtained with conventional instruments. The values determined here are, within experimental error, in agreement with the calculated results over a large range of depolarization ratios.
Spectroscopic evidence for resin‐reinforced dentine by a Raman microprobe technique
Authors: Suzuki Masako , Kato Hiromasa , Wakumoto Sadao , Katagiri Gen , Ishitani Akira
Published: May 2005

A Raman microprobe technique was applied to analyse the chemical components at the interface layer between dental adhesive resins and dentine. Raman spectra from each spot (ca. 2 μm in diameter) on the flat surface perpendicular to the interface were measured individually. These spectra indicate the coexistence of the resin and dentine components in a thin layer (ca. 5 μm in depth) of the dentine side. This provides spectroscopic evidence for the formation of resin‐reinforced dentine.
Method for the automatic determination of laser beam polarization and intensity parameters for the measurement of Raman optical activity
Authors: Gunnia Uma , Davies Mark A. , Diem Max
Published: May 2005

A method for the quantitative determination of the laser beam deflection on passage through an electro‐optic modulator is presented. The hardware used to determine simultaneously the beam polarization parameters and deflections is described, and a procedure for minimizing these deflections is outlined. Examples of artifacts caused by the motion of the laser beam in the observation of Raman optical activity are presented.
Laser Raman study of phase transitions in [N(CH3)4]2COCl4 single crystals
Authors: Rathore R. P. , Khatri S. S. , Chakraborty T.
Published: May 2005

Temperature‐dependent Raman spectra of oriented single crystals of [N(CH3)4]2CoCl4 are reported. An assignment of the observed Raman bands has been made and it was found that the N(CH3)4+ and CoCl42− groups occupy sites of Cs symmetry in the lattice at room temperature. However, because of rapid reorientation, the CoCl42− groups retain an effective tetrahedral symmetry. The prototypic to incommensurate to commensurate phase transitions are associated with the orientational dynamics of the CoCl4 tetrahedra. The monoclinic to orthorhombic super lattice phase transition at 122 K in [N(CH3)4]2CoCl4 is triggered by the distortion of the N(CH3)4+ groups in the lattice.
Raman tensors for planar and pyramidal AB3 molecules
Authors: Bródka A. , Stryczek B.
Published: May 2005

On the basis of bond polarizability model, expressions for second derivatives of the polarizability tensor with respect to the normal coordinates of planar and pyramidal AB3 molecules are presented. Using the results obtained, the relationship between the first and the second derivatives of the mean polarizability is found.
Resonance Raman analysis of astaxanthin–protein complexes
Authors: Merlin Jean Claude
Published: May 2005

A survey of resonance Raman spectra of carotenoproteins, including astaxanthin, is presented. The data are discussed and compared with absorption measurements in order to establish the mode of binding. Three mechanisms seem to be dominant in explaining the changes which occur in the resonance Raman and absorption spectra of astaxanthin. The polarization of the π‐electron system is responsible for the large red shift in the absorption λmax and the decrease in the CC stretching wavenumber. A distortion of the backbone plane involving double bonds can produce an increase of the CC stretching wavenumber and a red shift of the absorption band. Effects of the medium on excited states can produce red or blue shifts of the absorption band without perturbation of the ground electronic state properties. The interference of these mechanisms can explain the observed changes in the resonance Raman spectrum of astaxanthin bound to proteins and the great diversity of the results.
Laser Raman and infrared spectra of Rochelle salt crystals
Authors: Bhattacharjee R. , Jain Y. S. , Raghubanshi G. , Bist H. D.
Published: May 2005

A systematic analysis of the IR and Raman spectra of Rochelle salt (NaKC4H4O6 · 4H2O) in terms of the standard frequency correlations, deuteration shift and typical nature (with respect to intensity and width) of bands due to different modes is reported. The bands due to the internal modes (excluding some skeletal modes) of the C4H4O ion appear as doublets. For certain modes [e.g. βCH, νC(OH) and δCOO] doublets arise owing to interactions between two identical oscillations of two identical groups in COO(HO)HCCH(OH)COO2−, while for other modes (e.g. νCH, ν, ν, δCOH and τCOO) they arise owing to crystallographically distinguishable sites for two identical oscillators.
Raman intensities of liquids: Precise relative measurement of some potential secondary standards, and an interim scale of absolute intensities for blue and green excitations
Authors: Eysel Hans H. , Bertie John E.
Published: May 2005

The spinning divided Raman liquid cell has been used to measure the relative integrated Raman intensities of several bands of C6H6(I), CCI4(I), C6H12(I), C6D6(I), CH3CN(I), CH2CI2(I), SO(aq.), and CIO4 −(aq.) at room temperature. To convert these relative intensities to absolute scattering activities, the average of the eight literature values of the absolute Raman scattering cross‐section of the 992 cm−1 band of C6H6(I) under blue or green excitation was used. This yielded an unpolarized scattering activity per molecule of 640 ×10−9 cm4 g−1, with a standard deviation of 80 ×10−9 cm4 g−1 [in SI units, 792 ×10−34 and standard deviation 100 ×10−34 (C m2/V)2/(m2 kg)]. It is suggested that this value can be used as the basis for an interim scale of Raman scattering intensities. The scattering activities on this scale are higher than those in the literature because the benzene calibration value is higher than has been used previously. The relative scattering activities obtained agree well with those of Nestor and Lippincott. It is suggested that fairly weak and depolarized bands are often better secondary standards for relative intensity measurements than the very strong, very polarized bands that have traditionally been used.
Raman and far‐infrared study of the polar single crystals of 3‐(4‐chlorophenyl)‐2‐cyanopropenonitrile
Authors: Bugueno‐Hoffmann Rosa , Romain François , Pasquier Bernadette
Published: May 2005

Low‐frequency Raman and infrared spectra of a single crystal of 3‐(4‐chlorophenyl)‐2‐cyanopropenonitrile have been obtained and an assignment of the bands to their symmetry species has been made. Normal coordinate calculations using a dynamic lattice model with only a short‐range atom‐atom potential confirm roughly the experimental assignments but suggest the need to introduce an electrostatic potential in the lattice mode calculation of this polar crystal. Polarized infrared reflection spectra have been studied in order to determine the longitudinal and transverse optical frequencies, damping factors, oscillator strengths and induced dipole moments of the optical phonons. Approximate dynamic charges on the CN groups and on the whole molecule were estimated.
Resonance Raman and infrared spectra of the Pr(PAN)3 complex
Authors: Drożdżewski Piotr M.
Published: May 2005

The complex of praseodymium with 1‐(2‐pyridylazo)‐2‐naphthol (HPAN) has been investigated by resonance Raman and IR spectroscopy. It has been found that the Pr(PAN)3 complex exhibits tautomerism in various organic solvents. The excitation profiles of the observed Raman bands have been obtained and used for vibrational band assignments.
Optical spectroscopic studies of the polymorphic forms of 1, 4‐dihydroxyanthraquinone
Authors: Dutta Prabir K. , Lee B. S.
Published: May 2005

Electronic, infrared and resonance Raman spectra of the two crystalline polymorphic forms of 1, 4‐dihydroxyanthraquinone are reported. The differences in the spectral properties are explained on the basis of the intermolecular hydrogen bonds in one form compared with intramolecular hydrogen bonds in the other form. The intermolecular interaction leads to exciton splitting and strong hypochromic effects in the resonance Raman spectrum. The optical properties of the intramolecular hydrogen bonded form resemble that of the anthracycline drug adriamycin and serves as a useful model.
Detection of calcific deposits in atherosclerotic lesions by laser Raman spectroscopy
Authors: Clarke R. H. , Hanlon E. B. , Brody H. , Isner J. M.
Published: May 2005

The laser Raman scattering from calcified regions of diseased cardiovascular tissue samples dissected from the coronary arteries and aortic valves was measured. The spectra reveal the characteristic vibrational features of the phosphate grouping in the solid state. Spectral features for the calcified artery segments and aortic valves are compared for details of the chemical and structural makeup of the calcific lesions.
Raman spectra and binding of CuII to purine nucleotides
Authors: Carmona P. , Huong P. V. , Gredilla E.
Published: May 2005

Raman spectra of adenosine 5′‐monophosphate, poly(rA), guanosine 5′‐monophosphate and their CuII complexes have been obtained and analysed by referring to spectra of D‐, 15N‐ and 13C‐labelled nucleobases. The greatest spectral changes on attachment of CuII to these nucleotides are associated with changes in the five‐membered ring and suggest that the metal binds preferentially to N‐7 of nucleobases. However, in the CuII coordinated poly(rA) species, N‐1 binding sites are also present to some extent, as deduced from the comparison of the Raman spectrum of the Cu‐poly(rA) complex with that of the protonated polynucleotide. In the complexes of guanosine 5′‐monophosphate with CuII, the guanine residue is located at the anti position with respect to the ribose moiety through the glycosidic bond. In all cases, strong changes are also recorded for characteristic bands of phosphate groups, indicating their participation as ligands surrounding CuII.
Dunham coefficients of 14N2 from CARS measurements of high vibrational states in a low‐pressure discharge
Authors: Lavorel B. , Millot G. , Lefebvre M. , Péalat M.
Published: May 2005

Spectroscopic constants of the X 1Σg+ ground state of 14N2 are deduced from CARS spectra recorded in a 4 Torr d.c. N2 glow discharge. Vibrational states up to ν = 14 have been observed but only the 11 lower levels which have a good signal‐to‐noise ratio have been processed. The Dunham constants that were deduced yield vibrational band centre positions in good agreement with those of Lofthus and Krupenie.
Raman and force‐field studies of potassium tetrabromoindate in the solid state
Authors: Lorriaux‐Rubbens A. , Wallart F. , Wignacourt J. P.
Published: May 2005

Raman spectra of a single crystal of KInBr4(space groupPnna) have been recorded in the temperature range 298–80 K and assigned. The overlapping of bands due to fundamentals and lattice modes leads to some complexity in these results. A force‐field calculation has been made to complete the interpretation.
Raman and infrared spectra of some aromatic amine–sulphur dioxide molecular complexes
Authors: Faria D. L. A. , Santos P. S.
Published: May 2005

The Raman and infrared spectra of the molecular complexes formed by sulphur dioxide and aniline, N‐methylaniline (NMA), N, N‐dimethylaniline (DMA), N, N‐diethylaniline (DEA), p‐phenylenediamine (PPD) and N, N, N′,N′ ‐tetramethyl‐p‐phenylenediamine (TPD) were obtained. With NMA, DMA and DEA only minor changes were observed in the vibrational frequencies of the amines and the SO2 vibrational shifts show that the complexes are considerably weaker than the well known trimethylamine‐sulphur dioxide complex. On the other hand, with PPD and TPD there are significant variations in the spectra of the amines on complexation and the shifts of the SO2 vibrational frequencies show that the interaction is comparable in strength to that existing in the trimethylamine‐sulphur dioxide complex. In the aniline‐sulphur dioxide complex the spectral data reveal strong intermolecular hydrogen bonding interactions.

The pre‐resonance enhancement observed for the DMA and TPD complexes confirms the participation of the SO2 moiety in the chromophoric group and adds evidence for the change‐transfer nature of the interaction.
Raman spectroscopy of L‐tryptophan‐containing peptides adsorbed on a silver surface
Authors: Lee Hong In , Suh Se Won , Kim Myung Soo
Published: May 2005

Surfac‐enhanced Raman spectra of L‐tryptophanylglycine (L‐Trp‐Gly) and L‐tryptophanylglycylglycine (L ‐Trp‐Gly‐Gly) adsorbed on a silver surface were obtained. More detailed investigations than in a previous study on the surface‐enhanced Raman scattering from L‐tryptophan (L‐ Trp) and glycyl‐L‐tryptophan (Gly‐L‐Trp) were also made. It was found that L‐Trp and the above peptides adsorb on the silver surface via both the carboxylate (COO−) and the amino (NH2) groups. Interestingly, the nitrogen atom of the indole ring of L‐Trp was found to bind to the surface only when L‐Trp is the C‐terminal residue.
Raman intensities of phosphate and diphosphate ions in aqueous solution
Authors: Eysel Hans H. , Lim Kye Taek
Published: May 2005

The Raman intensity spectra of potassium phosphate and diphosphate in aqueous solution have been measured against perchlorate solution as an external standard. Including the intensities of triphosphate, proportionality was found between the total trace scattering, which covers the PO stretch frequencies only, and the number of PO bonds. The force field for PO was revised according to the requirement of the intensity ratio of ν3 and ν4. A tentative force field for P2O was calculated. Based on these normal coordinate analyses, the electro‐optical parameters of PO bonds in phosphate and pyrophosphate are given.
Raman spectroscopy using a DEC PDP 11/34 computer
Authors: Armstrong D. P. , Fletcher W. H. , Trimble D. S.
Published: May 2005

The interface between a Jobin‐Yvon Raman spectrometer and A DEC PDP 11/34 computer is described, and an outline of the operating principles and software is given.
A low‐temperature bulk electrolysis cell for in situ resonance Raman spectroelectrochemistry: Observation of the FeIVO stretching frequency for electrogenerated ferryl tetramesitylporphyrin
Authors: Czernuszewicz Roman S. , Macor Kathleen A.
Published: May 2005

A simple, small‐volume, low‐temperature bulk electrolysis Raman spectroelectrochemical cell has been constructed which allows collection of resonance Raman (RR) spectra in situ from a rapidly stirred electrolysed solution. The cell has been used to obtain the first RR spectrum of electrochemically generated ferryl tetramesitylporphyrin (TMPFeIV O), formed at −40°C by electrooxidation of TMPFeIIIOH in CH2CI2 solution.
Raman spectra of the NaH2PO4 crystal
Authors: Choi B. K. , Lee M. N. , Kim J. J.
Published: May 2005

Room‐temperature and low‐temperature (10 K) Raman spectra of a single crystal NaH2PO4 were obtained for various polarizations. The polarization characteristics of the Raman spectra remained unchanged throughout the whole temperature range studied. This confirms that there is no phase transition in this crystal at least down to 10 K. High‐frequency H modes showed the well known ABC‐type three‐band structure and correlated with OH…︁O bond length.
Vibrational spectra of pyrazincarbonitrile and [15N]pyrazincarbonitrile
Authors: Delgado M. J. Martin , Márquez F. , Suero M. I. , Marcos J. I.
Published: May 2005

Pyrazinecarbonitrile and its 15N isotopic derivative were synthesized with an isotopic content of 99.4% and then Raman and infrared spectra recorded and assigned on the basis of isotopic shifts and depolarization ratios. The geometry in an MNDO approximation was also optimized.
Raman single crystal studies of spinel type MCr2S4(M  Mn, Fe, Co, Zn, Cd), MIn2S4(M  Mn, Fe, Co, Ni), MnCr2–2xIn2xS4 and Co1‐xCdxCr2S4
Authors: Lutz H. D. , Becker W. , Müller B. , Jung M.
Published: May 2005

The Raman spectra of single crystals (grown by chemical vapour transport with I2, AlCl3, CrCl3 and InCl3 as transporting agents) and polycrystalline samples of spinel type MCr2S4 (M  Mn, Fe, Co, Zn, Cd), MIn2S4 (M  Mn, Fe, Co, Ni), MnCr2–2xIn2xS4 and Co1–xCdxCr2S4 were recorded. The main results obtained are (i) large resonance enhancement effects, (ii) breakdown of the translation symmetry in inverse spine (MIn2S4), which results in band broadening and the observation of more bands than group theoretically allowed, e.g. a clustering mode (A1g) at about 250 cm−1, (iii) two‐mode behaviour of the breathing modes of the tetrahedral MS4 units (A1g) in both spinel solid solutions and partly inverse ternary spinels and (iv) frequency shifts of the observed bands caused by the tetrahedrally coordinated metal ions due to mass effects (F2g modes) and both bonding (ionic charge, covalency) and repulsion interactions (A1g modes).
Spectroscopic studies on trifluoroacetyl iodide, CF3C(O)I
Authors: Védova C. O. Della , Aymonino P. J. , Bravo R. D.
Published: May 2005

IR, Raman and UV spectra of CF3C(O)I have been obtained and assigned to the expected vibrational normal modes of the molecule and electronic transitions in the CO group. Internal force constants were calculated from vibrational data. The results agree with data reported for other CF3C(O)X compounds.
Infrared and resonance Raman spectra of hydroxophthalocyaninatomanganese(III)
Authors: Quinzani O. V. , Jubert A. H. , Aymonino P. J.
Published: May 2005

The infrared and resonance Raman spectra of the solid complex hydroxophthalocyaninatomanganese(III) were obtained. The excitation profiles of some vibrational modes show resonance within the electronic bands in the visible region, and on this basis several vibrational and electronic absorption bands are assigned.
Raman spectral studies of ion–molecular interactions of lithium bromide and lithium iodide with dimethyl sulphoxide
Authors: Ramana K. Venkata , Singh Surjit
Published: May 2005

Raman spectra in the CH and SO stretching and SO bending regions are reported for solutions of lithium halides and tetrabutylammonium bromide (TBAB) in dimethyl sulphoxide (DMSO) and DMSO‐d6. The CD stretching band of DMSO‐d6 shows two components in solutions of TBAB with DMSO‐d6, whereas the CH stretching band of DMSO for solutions of LiX (X = Br and I) in DMSO show some broadening and asymmetry in the low‐frequency region. The SO stretching bands show changes in band shapes and band contours in solutions of electrolytes in DMSO. Fourier deconvolution of CH and SO stretching bands were carried out to gain more information regarding number of components present under the broad structured bands. All the solutions show a significant decrease in the intensity of the SO bending bands when compared with the neighbouring CS bending band. The results are discussed in terms of anion‐ and cation–molecular interactions with DMSO.
Hypersonic behaviour of bismuth germanium oxide (Bi4Ge3O12)
Authors: Prieto C. , Pelous J. , Boissier M. , Contreras L.
Published: May 2005

Brillouin scattering was performed between 80 and 300 K in order to study the hypersonic properties of Bi4 Ge3O12 crystals. The velocity and the attenuation of longitudinal acoustic phonons propagating along the [100] direction were measured for frequencies near 34 GHz. The Brillouin shift shows a variation with temperature which is five times lower than that observed in another bismuth germanium oxide, Bi12 GeO20. The hypersound attenuation is also very low and seems to be independent of temperature.
Raman spectroscopic investigation of N‐alkylurotropinium polyiodides
Authors: Mittag H. , Stegemann H. , Füllbier H. , Irmer G.
Published: May 2005

N‐Alkylurotropinium polyiodides, UrRIx, with different iodine contents and different sizes of alkyl group were investigated by Raman spectroscopy. The spectra were recorded for wavenumber shifts up to 500 cm−1. It was found that the triiodides, UrRI3, contain a symmetrical linear I3− ion. The pentaiodides, UrRI5, contain no triiodide unit; the anion structure can be described as nearly symmetrical, rectangular L‐shaped I5−. An interpretation of the Raman spectra of the heptaiodides, UrRI7, is that the anion corresponds to an I5−. I2 structure. This is the first proof of such a heptaiodide. A review of previously published data on the Raman spectra of polyiodides is also given.
Vibrational spectra of trifluoromethylthiosulphenyl chloride, CF3SSCI
Authors: Della Védova C. O.
Published: May 2005

The Raman spectrum of liquid trifluoromethylthiosulphenyl chloride and its IR spectra in the vapour and solid phases in neon and argon matrices were recorded. Polarized Raman spectra of liquid trifluoromethylthiosulphenyl chloride suggest C1 symmetry. Assignment of 14 of the 15 fundamental vibrations is carried out. A correlation between the S‐‐S stretching wavenumber and the sum of the group electronegativities of the disulphan substituents is proposed.

The valence force constants were calculated by semi‐empirical methods and the values obtained compare favourably with results from previous calculations on related compounds.
Hyper‐Raman scattering with circularly polarized light
Authors: Subramanian R. , Krishnamurthy N. , George S.
Published: May 2005

The characteristics of hyper‐Raman scattering employing circularly polarized incident radiation were studied using Cartesian tensor methods. Expression for the reversal factor, P(θ), and circularity, RC(θ), and their relationship with the depolarization factors, ρ⊥ and ρn, have been derived. An analysis of hyper‐Raman spectrum of a molecule with D3h symmetry is presented.
Rotational diffusion in methyl iodide: Bandshape analysis of degenerate vibrational modes
Authors: Wang S. P. , Yuan P. , Schwartz M.
Published: May 2005

The Raman spectral bandshapes of the ν1(A1), ν3(A1) and ν4(E) vibrations of CH3I were studied as a function of temperature in the liquid phase. Perpendicular diffusion coefficients calculated from ν3 agreed well with earlier reported results. The degenerate CH3 stretching vibration, ν4, was analyzed via fitting by a model incorporating two Lorentzian lineshapes. Values of the parallel diffusion constants, D∥, determined using only the narrower component were in excellent semi‐quantitative agreement with those predicted by the free rotor model of molecular reorientation. Analysis of the room‐temperatur Raman spectrum of ν5(E) yielded the same value of D∥ as that calculated from ν4. The room‐temperature infrared spectral intensities of ν5 were fitted by a model with a narrow Lorentzian containing contributions from rotational and vibrational relaxation superposed on a second component introduced to account for the broad background absorption. D∥ determined from the IR bandwidth was in good agreement with values obtained from the Raman spectra of ν4 and ν5. These results demonstrate the utility of analyzing degenerate vibrational modes to determine the parallel diffusion coefficients in C3v molecules.
Surface‐enhanced Raman spectra of acid radicals adsorbed on silver particles
Authors: Chun‐ping Zhang , Feng‐qi Yu , Guang‐yin Zhang
Published: May 2005

The surface‐enhanced Raman spectra of NO3− and B(OH)4− were obtained by adding metal ions to a silver sol containing these anions, and the enhancement factor was estimated to be 104‐105 for NO3−. We think this is because metal ions form a complex compound with NO3− on the surface of the silver particles, leading to the formation of an O–Ag bond via the lone pair of electrons of the NO3−. The Raman spectrum of this bond has been observed. In addition, a tentative method for testing for trace ions is proposed.
Spectroscopic properties of methyl thiolfluoroformate, FC(O)SCH3
Authors: Della Védova C. O.
Published: May 2005

Detailed IR and Raman data for methyl thiolfluoroformate, FC(O)SCH3, point to the existence of a trans (F, CH3) conformer with Cs symmetry in both the vapour and liquid phases. For all but the torsional modes of this conformer, wavenumbers are reported and were used to calculate an approximate force field. The study was complemented with the characterization of the compound using the 13C 19F and 1H NMR, UV and mass spectra. A semi‐empirical calculation was performed for the molecule, and the deduced force constants were compared with those derived from experimental data.
Raman spectral study of the Mg(ClO4)2NaNCSH2O system at ambient and elevated temperatures
Authors: Antić‐Jovanović A. , Jeremić M. , Lalić M. , Long D. A.
Published: May 2005

Raman spectra of Mg(ClO4)2NaNCSH2O mixtures were analysed as a function of the concentration ratio of the components at ambient and elevated temperatures. The strong perturbation of the thiocyanate spectrum observed in the regions of the ν1 and ν3 vibrations is interpreted in terms of complex formation. Band intensity measurements of resolved bands gave evidence for two complex species: [MgNCS]+ and [Mg(NCS)2], the former being discernible over the whole concentration range studied. The variations in the spectrum of the Td perchlorate ion at very low water‐to‐salt molar ratios are explained as indicating a coordination of ClO4− unit and lowering of the symmetry of C2ν.
Vibrational spectra and normal coordinate analysis of monohalogenated nitrobenzenes
Authors: Muralidhar Rao P. , Ramana Rao G.
Published: May 2005

The Raman and infrared spectra of o‐, m‐ and p‐fluoronitrobenzenes, o‐, m‐ and p‐chloronitrobenzenes, m‐ and p‐bromonitrobenzenes and o‐, m‐ and p‐iodonitrobenzenes were measured. Far‐infrared and Raman polarization measurements were made wherever possible. A normal coordinate analysis was carried out for both the in‐plane and out‐of‐plane vibrations of these molecules using an 82‐parameter modified valence force field. An overlay least‐squares technique was employed to refine the force constants using 378 frequencies of the molecules to obtain a converged set of meaningful force constants. The reliability of the force constants so obtained was tested by making a zero‐order calculation for o‐bromonitrobenzene. The potential energy distributions and eigenvectors calculated in the process were used to make unambiguous vibrational assignments of all the fundamentals.
Raman spectroscopy of cyclohexanethiol adsorbed on a silver surface
Authors: Kwon Cheol Kee , Kim Myung Soo , Kim Kwan
Published: May 2005

The surface‐enhanced Raman scattering of cyclohexanethiol was investigated in a silver sol. Cyclohexanethiol was found to adsorb dissociatively after losing its thiol proton and adsorption was found to occur via its sulphur atom. Both the equatorial and axial chair conformers were found to exist on the surface at low surface coverage. However, at full monolayer coverage, the equatorial chair was the sole conformation of the adsorbed thiolate. An improved vibrational assignment for the molecule has been made.
Preparation and spectroscopic properties of chlorocarbonylfluorocarbonyl disulphide, ClC(O)SSC(O)F
Authors: Védova C. O. Della
Published: May 2005

Chlorocarbony fluorocarbonyl disulphide, CIC(O)SSC(O)F, was prepared from bis(fluorocarbonyl) disulphide and BCI3. IR data of the vapour, liquid and matrix‐isolated CIC(O)SSC(O)F at low temperature together with the Raman spectrum of the liquid suggest the existence of a more abundant non‐planar conformer with symmetry C1 in both the vapour and liquid phases. For all but the torsional modes of this conformer wavenumbers are reported. However, the valence force constants were calculated by a semi‐empirical method. The study was complemented with the characterization of the compound by 19F NMR and mass spectra.
Resonance Raman scattering in azo dyes
Authors: Cataliotti R. S. , Morresi A. , Paliani G. , Zgierski M. Z.
Published: May 2005

Resonance Raman excitation profiles of some azo dyes were studies and interpreted in terms of a model that treats vibratious as displaced harmonic oscilators. It is shown that the visible absorption spectrum is formed by two overlapping electronic transitions of a mixed charge‐transfer and nπ* character.
Lattice dynamics and intermolecular forces in P4Se3 derived from the Raman spectra
Authors: Bougeard Daniel
Published: May 2005

The Raman‐active lattice modes of crystalline P4Se3 at room temperature have been calculated in the rigid–body approximation by using estimated atom‐atom potentials for the Se atoms. The agreement is satisfactory and reveals several types of couplings of the different degrees of freedom. The calculated lattice energy is of the correct order of magnitude. The potentials obtained show characteristic features which correlate with the presence of short SeSe distances in the crystal.
IR and polarized Raman spectra of K4P4O12Te(OH)62D2O
Authors: Mathew Xavier , Nayar V. U.
Published: May 2005

IR and Raman spectra of K4P4O12Te(OH)62D2O and K4P4O12Te(OH)62H2O have been recorded and analysed. The P4O12 modes are assigned on the basis of characteristic vibrations of the POP and PO2 groups. The P4O4 ion has C2h symmetry and the P4O12 and TeO6 groups coexist in this compound. Two crystallographically distinct water molecules exist in K4P4O12Te(OH)62H2O. The water molecules form strong hydrogen bonds.
Resonance Raman spectrum of phenolphthalein in alkaline solution and vibrational spectra of the pure compound and its potassium salts
Authors: Chattopadhyay S. , Kastha G. S. , Nandy S. K. , Brahma S. K.
Published: May 2005

Raman and infrared spectra of phenolphthalein and its white and pink potassium salts together with the resonance Raman spectrum of the parent compound in alkaline solution were studied. From careful comparison of the spectra, the observed frequencies were assigned to appropriate vibrational modes and from these assignments frequencies originating from vibrations of hybridized bonds in the resonating molecular forms of phenolphthalein, believed to be present in alkaline solution were identified. It was shown that such resonating forms are present in the pink but not the white potassium salt. The spectral data also indicate that the vibrations of the carboxylate ion group do not take part in the resonance Raman phenomenon.
Temperature and pressure study of vibrational relaxation in liquid benzene
Authors: Wrzalik R. , Nikiel L. , Bródka A.
Published: May 2005

The isotropic Raman spectra of monodeuterated benzene (C6H5D) in the region around 3000 cm−1 were studied at temperatures of 30, 60 and 90°C and pressures up to 2 kbar. In this frequency region we observed two overlapping bands (ν1 and ν12), and hence an additional broadening process, the energy relaxation to other modes, gives a contribution to the band widths. The changes in frequencies and band widths are interpreted in terms of the Schweizer and Chandler theory.
Surface‐enhanced Raman scattering of zinc tetrakis(4‐N‐methylpyridyl)porphyrin
Authors: Song Ok‐Keun , Yoon Min‐Joong , Kim Dongho
Published: May 2005

The surface‐enhanced Raman spectra of zinc tetrakis(4‐N‐methylpyridyl)porphyrin in silver sol using various excitation wavelengths are reported. On the basis of comparison of the patterns of the relative enhancement between SERS and normal Raman bands and using previous theoretical calculations, this molecule is found to be anchored on the silver surface with ‘flat‐on’ geometry. Generally, out‐of‐plane porphyrin and pyridyl modes are relatively strongly enhanced relative to the in‐plane porphyrin skeletal modes in SERS as compared with normal Raman spectra. The mode assignment for this molecule was attempted based on the enhancement pattern of Raman modes depending on the geometry of the adsorbed molecule and the mode character. The selective enhancement of some modes would be helpful in the vibrational mode assignments of porphyrins having peripheral phenyl groups.
Fourier transform Raman spectroscopy of illicit drugs
Authors: Hodges C. M. , Hendra P. J. , Willis H. A. , Farley T.
Published: May 2005

Fourier transform (FT) Raman spectroscopy was investigated as a means of characterizing pure amphetamine sulphate, cocaine hydrochloride, heroin and diluted (‘cut’) samples of these drugs at drug concentrations down to 5%. The pure compounds give spectra that are excellent for rapid identification, as do samples cut with sorbitol. Some cutting agents are fluorescent, however, and identification then presents difficulties. The major advantage of FT Raman spectroscopy over other techniques for the testing of illicit drugs is that no sample preparation is needed. The test is very fast (3 min), and after examination the sample can be completely recovered in the same form as that in which it was received, so that it can, if required, be submitted to other test procedures.
Effect of temperature on the fermi resonance and the resonance intermolecular coupling in the Raman spectra of liquid water
Authors: Sokołowska Anna
Published: May 2005

The temperature dependence of the isotropic and anisotropic Raman components for the H2O and D2O stretching vibrations has been studied. The results of resolution of the isotropic component into three constituents and the anisotropic into four constituents are compared with the values calculated by the perturbation method for a superposition of the Fermi and intermolecular coupling resonances. The experimental results were found to agree qualitatively with the predicted values.
Raman and far‐infrared spectra of crystalline formaldehyde, H2CO and D2CO
Authors: Weng S. X. , Anderson A. , Torrie B. H.
Published: May 2005

Raman and far‐infrared spectra of crystalline formaldehyde and its fully deuterated analogue have been recorded over the frequency range 25–350 cm−1 and at temperatures of 80 and 20 K; 16 Raman and 8 far‐infrared lattice peaks have been resolved. Isotopic frequency shifts together with inertia and intensity arguments are used to assign the peaks. Raman spectra of the internal vibrational modes of solid formaldehyde are also presented, with several crystal field splittings observed. The results are consistent with a group theoretical analysis based on the molecular and crystal symmetries.
Electronic and pre‐resonance Raman spectra of the anion [VO(C3H2O4)2]2−
Authors: Baran Enrique J. , Jubert Alicia H. , Rocha Adriana L.
Published: May 2005

A study of the Raman, pre‐resonance Raman and electronic spectra of the [VO(C3H2O4)2]2− anion was performed. The excitation profiles of the vibrational modes that show pre‐resonance on excitation with laser lines within the electronic bands in the visible region are reported. On this basis, the VOmalon. vibrations could be unambiguously assigned and stronger experimental support is provided for the origin of some of the electronic transitions.
Raman spectrum of Cu(NO3)2 · N2O4
Authors: Givan A. , Loewenschuss A.
Published: May 2005

The Raman spectrum of the coordination compound Cu(NO3)2 · N2O4 is reported. X‐ray diffraction studies showed its lattice to be composed of layers of polymeric [Cu(NO3)3]− anions (in which the Cu—nitrate bonds are bridging) and of discrete charge‐balancing NO+ cations, whereas infrared results indicated the presence of discrete covalent N2O4 molecules in the lattice, and some interaction of Cu atoms with the NO+ units. Raman spectra of this highly hygroscopic and deeply coloured compound are in accord with the structural conclusions of the x‐ray diffraction work.
Resonance raman spectrum of sirohydrochlorin in desulfoviridin from Desulfovibrio gigas
Authors: Lai K. K. , Yue Kwok To
Published: May 2005

Resonance Raman spectra with excitations in the Soret region are reported for desulfoviridin, the sulfite reductase from Desulfovibrio gigas. Desulfoviridin contains sirohydrochlorin, a hydroporphyrin of the type isobacteriochlorin. The typical spectrum shows a large number of bands, with the prominent v4* mode at 1336 cm−1. Using perturbation and group theories, we were able to develop some conceptual understanding of the in‐plane vibration modes of isobacteriochlorin. This has enabled us to arrive at the tentative conclusion that the sirohydrochlorin prosthetic groups in desulfoviridin are not coupled to any metal ion(s).
Linewidths in the pure rotational Raman spectra of hydrogen chloride and carbon monoxide and of nitrogen and carbon monoxide perturbed by hydrogen chloride
Authors: Edwards H. G. M. , Long D. A. , Sherwood G.
Published: May 2005

Pressure‐broadening coefficients, σp, have been determined for self‐broadening of pure rotational Raman lines of carbon monoxide and for pure rotational Raman lines of hydrogen chloride, and carbon monoxide and nitrogen perturbed by hydrogen chloride at 293 K. The results are discussed and compared with calculated and experimental σp values in the literature.
Spectra and structure of organophosphorus compounds XXXVIII—Raman and infrared spectra, vibrational assignment, conformational stability and normal coordinate analysis for ethylphosphonic dichloride
Authors: Durig J. R. , James C. G. , Hizer T. J.
Published: May 2005

The Raman (3500‐10 cm−1) and infrared (3500‐50 cm−1) spectra of solid CH3CH2P(O)Cl2 and CD3CD2P(O)Cl2 and the infrared spectra of the gases were recorded. Additionally, the Raman spectra of the liquids were measured and qualitative depolarization ratios were obtained. Since several distinct Raman lines disappear from the spectra on going from the fluid to the solid states, it is concluded that the molecule exists as a mixture of trans and gauche conformers. A variable‐temperature study of the Raman spectrum of the liquid yielded an enthalpy difference between the conformers of 72 ± 10 cm−1 (206 ± 27 cal mol−1). The trans conformer is the more stable form in the liquid, and the only one present in the solid. On the basis of band intensities, group frequencies and depolarization values, a complete vibrational assignment is proposed for the trans conformer. This assignment is supported by a normal coordinate analysis utilizing a modified valence force field. These results are compared with those from some similar molecules.
Polarized Raman and infrared spectra of (NH3)2(CH2)2HXO4 (X =P, As)
Authors: Philip Daizy , Aruldhas G.
Published: May 2005

Polarized Raman and IR spectra of (NH3)2(CH2)2HPO4 and (NH3)2(CH2)2 HAsO4 have been recorded and analysed. Crystal field effects are found to be stronger in the phosphate than in the arsenate and the symmetry of the anion is reduced from C3v to C1. In the arsenate the ethylenediammonium groups are identical whereas in the phosphate they are crystallographically different. The effects of strong vibrational coupling between PO(H) stretching and POH out‐of‐plane bending modes are observed in the phosphate. It is found that the HAsO has a greater angular distortion.
Normal‐coordinate treatment of a nucleic base pair model in its crystalline state: 1‐Methylcytosine–9‐ethylguanine
Authors: Lagant P. , Vergoten G. , Derreumaux P. , Dhennin R.
Published: May 2005

A normal‐mode analysis of a nucleic base pair model, 1‐methylcytosine–9‐ethylguanine in the crystal state was performed in order to analyse the degree of participation of the intra‐ or intermolecular hydrogen bonds in the vibrational modes. The base pair model compound crystallizes in the P1 space group (triclinic system with two molecules per unit cell); 125 adjacent cells were necessary to take into account the intramolecular hydrogen bonds. A General Valence Force Field was derived from previous studies on nucleosides. Comparison with experimental vibrational studies allows a good assignment of the observed bands. Mixing of the intra‐ and intermolecular hydrogen bond vibrational modes with the internal modes is observed over a large range of frequencies.
Solvent‐dependent vibrational relaxation studies in polar liquid
Authors: Purkayastha Anusree , Das Radhendu , Kumar Kamal
Published: May 2005

Isotropic Raman line broadening studies were carried out for the CO stretching mode of vibration in N,N‐dimethylformamide and cyclohexanone molecules in solution. The broadening for the Raman band is explained on the basis of hydrodynamic, multipole‐multipole, induction and dispersion forces. The intercept on the linear graph [Γiso vs f(ρ, η, n)] is explained on the basis of induction forces and multipole interactions for dipolar and non‐dipolar solvents.