bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of resonance Raman scattering from crystal violet deposited on island silver films
Authors: Chou Y. C. , Liang N. T. , Tse W. S. 
Published: May 2005

AbstractThe observed thickness dependence and excitation profiles of the surface‐enhanced resonance Raman scattering (SERRS) from crystal violet (CV) on silver films demonstrated the importance of surface roughness and chemical effects. Using different normalization schemes in studying the excitation profile of SERRS we were able to identify that there are three multiplicative contributions to the observed overall enhancement, viz. the electromagnetic effect, the molecular resonance effect and the charge‐transfer effect originating from the strong electronic interactions between CV and the metal islands.
Photoisomerization studies of pinacyanol using nanosecond time‐resolved resonance cars
Authors: Werncke W. , Tschol Tscho Jong , Weigmann H.‐J. , Pfeiffer M. , Lau A. , Rentsch S. , Graness A. 
Published: May 2005

AbstractResonance CARS spectra of the short‐lived photoisomer of pinacyanol were obtained. From the CARS line frequencies, intensities, line shapes and depolarization ratios it can be concluded that a cis‐isomer rather than a twisted configuration is observed.
Raman spectra of gases. XXVI—Trifluoroacetaldehyde
Authors: Durig J. R. , Guirgis G. A. , Van Der Veken B. J. 
Published: May 2005

AbstractThe Raman spectra from 3500 to 10 cm−1 of gaseous, liquid and solid trifluoroacetaldehyde (fluoral), CF3CHO, have been recorded and qualitative depolarization values were obtained for the fluid phases. Two of the bending fundamentals have been reassigned. The infrared gas‐phase band contours have been calculated and compared with the observed values. From the far‐infrared spectrum of the gas, the fundamental (66.2 cm−1) and overtone (128.6 cm−1) of the internal rotation have been identified. The barrier to internal rotation has been calculated to be 298±10 cm−1 (852±29cal mol−1). The spectrum of the solid is consistent with at least two molecules per primitive cell. These results are compared with earlier results and with similar parameters for some corresponding molecules.
Raman and infrared spectra and fundamental frequencies of 1,2,4,5‐tetrabromobenzene
Authors: Yadav R. A. , Shanker R. 
Published: May 2005

AbstractThe Raman spectrum of 1,2,4,5‐tetrabromobenzene has been recorded in powder form in the region 100–4000 cm−1 and the IR spectra in nujol mull and a CsI pellet in the region 200–4000 cm−1. Tentative vibrational assignments have been proposed assuming D2h point group symmetry. Observation of a number of overtone and combination bands enabled the inactive fundamentals and those fundamentals which were not observed experimentally to be estimated.
Depolarization dispersion curves of some Raman fundamentals in ferrocytochrome c and oxyhaemoglobin
Authors: Zgierski Marek Z. 
Published: May 2005

AbstractDepolarization dispersion curves and Raman excitation profiles of three fundamentals in ferrocytochrome c (1585, 1312 and 1363 cm−1) and oxyhaemoglobin (1583, 1376 and 1638 cm−1) are calculated togther with the corresponding absorption spectra in the region of 16000‐23000 cm−1. A four‐orbital model with two‐electron interaction term and vibronic coupling terms for the a1g, a2g, b1g and b2g vibrations is used in two‐mode calculations. It is shown that the observed depolarization dispersion curves indicate the presence of symmetry‐breaking A2g and B1g electronic perturbations in ferrocytochrome c and of a B2g off‐diagonal electronic perturbation in oxyhaemoglobin. These electronic perturbations lower the D4h symmetry of the porphyrin ring. It is also demonstrated that smaller vibronic perturbations become active in these molecules at lower symmetry. These vibronic perturbations result mainly from the symmetry‐forbidden (D4h group) linear dependence of the nuclear potential energy in the Q and B states and of the two‐electron interaction term on non‐totally symmetric vibrational coordinates.
Raman spectra of some complexes containing methyl‐, dimethyl‐ and trimethyl‐halophosphonium cations
Authors: Finch Arthur , Gates Peter N. , Muir Alan S. 
Published: May 2005

AbstractVibrational assignments for the skeletal modes of the solid‐state species (CH3)nPX5−n (X  Cl, Br; 1 ⩽ n ⩽ 3) have been made on the basis of their Raman Spectra. The results are consistent with ionic formulations (CH3)nPX4−n +X− and are compared with any previously available data. Two modifications of (CH3)2PCl2 +Cl− have been observed for the first time and their relative stabilities investigated. Raman spectra of the mixed halogen cationic compounds CH3PCl2Br+X−, CH3PClBr2 +X− and (CH3)2PClBr +X− are also reported and Lewis acid complexes of all the phosphonium cations show characteristic high‐frequency shifts in the PX stretching modes [relative to those in (CH3) RPX4−n +X−] which are rationalized in terms of anion‐cation interactions. CH3PCl4 has been observed in a molecular form and the transition to the ionic modification (at ca 160 K) has been monitored by variable temperature Raman spectroscopy.
Misassignment of the strong Raman band near 1000 cm−1 in some substituted benzenes, and the Herzberg versus Wilson convention for numbering the vibrations of benzene
Authors: Miller Foil A. 
Published: May 2005

AbstractMono, 1,3, 5‐substituted benzenes (and only these) have a very strong, highly poarized Raman band at 1000±10 cm−1. It is often misassigned as the symmetrical ring breathing, whereas in fact it is derived from the benzene trigonal ring deformation v6. In the current literature the vibrations of benzene are numbered according to either the Herzberg or the Wilson scheme. A plea is made for using only one convention, and reasons are gigen for choosing Herzberg's.
Raman intensities of liquids: Potential secondary standards for Raman shifts greater than 1000 cm−1
Authors: Eysel Hans H. 
Published: May 2005

AbstractRelative integrated Raman intensities of selection of bands of liquid of liquid C6H6, C6H6, C6H12, CH3CN, CH2Cl2 and 1,1‐dichloroethene (C2H2Cl2) have been measured using the external standard method and a bivided spinning cell. Absoulte scattering activities were computed from these relative intensities based on the scattering activity of cyclohexane (7680 × 10‐9 cm4 g‐1 per moleculey) integrated over the sum of CH stretch vibrations.
Vibrational spectroscopy at high pressures. Part 50. A Raman scattering study of MSCN (M = K, Rb, Cs, NH4) at high pressures
Authors: Adams David M. , Pogson Mark 
Published: May 2005

AbstractThe phase behaviour of the title compounds was studied at high pressures using Raman spectroscopy. The isostructural materials KSCN and RbSCN show two phase changes (12.5 and 45.5 kbar; 10.5 and 37.5 kbar, respectively) which appear to be second order in type. Structures and transition mechanisms are proposed for each phase. CsSCN has a different orthorhombic structure and shows only one phase change in the range studied, at 23.5 ± 1.5 kbar, which also seems to be second order. The known phase transition in NH4SCN at 2 kbar has been confirmed, and a new one found at 10 kbar. A monoclinic cell is proposed for the new phase.
Investigation of the photoisomerization process of bisdimethylaminoheptamethine by means of time‐resolved CARS
Authors: Lau A. , Werncke W. , Pfeiffer M. , Weigmann H.‐J. , Bok Kim Man 
Published: May 2005

AbstractResonance CARS measurements of the photoisomeriztion process of bisdimethylaminoheptamethine under different resonance and excitation conditions are presented and compared with model calculations. A Six‐level model—a Rulliere‐type model extended by one level—is suggested.
Raman scattering in lithium ammonium sulphate
Authors: Lemos V. , Gomes P. A. P. , Melo F. E. A. , Filho J. Mendes , Moreira J. E. 
Published: May 2005

AbstractPolarized Raman spectra of single crystals of lithium ammonium sulphate (LiNH4SO4) have been obtained. Detailed assignments of symmetry were made using selective scattering geometries. Separation of TO and LO components were either observed experimentally or calculated using oblique phonon frequency measurements.
Raman spectra of L(+)‐glutamic acid and related compounds
Authors: Shurvell H. F. , Bergin F. J. 
Published: May 2005

AbstractRaman spectra of aqueous solutions of L(+)‐glutamic acid were studied in the pH range 0.5–12.5. Various ionic species were identified from the spectra and the pH ranges in which they predominate were established. Solid‐state Raman spectra of L(+)‐glutamic acid and the hydrochloride and monosodium salt were recorded and the spectra assigned and correlated with the structures of the three molecules. Near‐infrared Fourier transform Raman spectra of the three solid compounds were recorded and are compared with the spectra obtained using dispersive instruments.
Raman spectroscopy of low‐temperature phases of RbAg4I5
Authors: Shawabkeh A. , Scott J. F. 
Published: May 2005

AbstractRaman spectra were obtained of single crystals of RbAg4I5 in an effort to confirm independently the far‐infrared results of Volkov and co‐workers that structural phase transitions occur at 44 and 30 K. The present results, that a strong ‘extra’ line occurs below 44 K at 12 cm−1, is in agreement with their measured value, confirming that the phase just below 44 K is non‐centrosymmetric, in agreement with their proposed C3 point group.
Origin of Raman spectral difference between spinning cell and flow cell measurements for bacteriorhodopsin photointermediates
Authors: Nakagawa M. , Maeda A. , Ogura T. , Kitagawa T. 
Published: May 2005

AbstractPrevious resonance Raman studies with the spinning cell technique indicated that the L550 intermediate gave a doublet at 1552 and 1539 cm−1 for the CC stretching mode whereas the results from the flow cell technique suggested that the two bands arise from different intermediates on the basis of different kinetic behaviour. This study has explored the origin of the discrepancy by applying both the double‐beam flow apparatus and the spinning cell to an identically prepared sample for observing transient resonance Raman spectra. It was found that the presence of a very small amount of dark adapted species caused the apparent differences in the kinetic behaviour of these two bands.
Raman and far‐infrared study of the lattice vibrations of solid nitromethane
Authors: Prystupa D. A. , Anderson A. , Torrie B. H. 
Published: May 2005

AbstractThe Raman and far‐infrared spectra of crystalline nitromethane and its fully deuterated analogue were recorded over the frequency range 20–400 cm−1 and at temperatures between 20 and 150 K. In the spectra of CH3NO2, 15 of the 21 Raman‐ and 13 of the 15 infrared‐active lattice modes predicted by group theory were observed. The corresponding numbers for CD3NO2 were 17 and 14, respectively. Isotopic frequency shifts together with inertia and intensity arguments were used to assign the peaks. Frequency coincidences in the two types of spectra are indicative of a non‐centrosymmetric cell. Several features are attributed to the torsional mode or interactions with this mode.
Temperature dependence of the Raman spectrum of fully deuterated acetanilide
Authors: Sauvajol J. L. , Almairac R. , Moret J. , Barthes M. , Ribet J. L. 
Published: May 2005

AbstractThe temperature dependence of the Raman scattering from a single crystal of acetanilide (ACN‐H) and fully deuterated acetanilide (ACN‐D) in the low‐frequency (phonon) and CO stretching regions was studied. The observed normal behaviour of the frequency shift of the CO stretching modes in ACN‐D, raises questions concerning several theoretical models previously proposed to explain the peculiar behaviour with temperature of the A1g stretching modes observed in ACN‐H. The forms of the low‐frequency Raman spectra for ACN‐H and ACN‐D are very similar, except in the frequency range 70‐120 cm−1, where an additional mode (denoted D′) is seen in the Raman spectrum of ACN‐D. A strong temperature dependence of the frequency of this band is observed. The origin of this mode is still undecided.
Resonance Raman investigation of meisenheimer complexes derived from 1,3,5‐trinitrobenzene
Authors: Santos P. S. , Gonçalves N. S. 
Published: May 2005

AbstractThe Raman spectra of Meisenheimer complexes derived from 1,3,5‐trinitrobenzene and proline, tryptophan, albumin and pyrrolidine were obtained. The spectra excited in and out of resonance with the electronic transition at ca. 460 nm show an outstanding enhancement of modes involving mainly the symmetric stretching and deformation of the NO2 groups. The results also indicate a marked reduction in the symmetric and asymmetric stretching frequencies, in addition to suggesting a decrease in symmetry on going from the parent nitro aromatic to the Meisenheimer complexes.
Surface‐enhanced resonance Raman scattering (SERRS) of ruthenium(II) heteroleptic complexes with 2,2′‐bipyridine and 1,4,5,8,9,12‐hexaazatriphenylene adsorbed on silver sols
Authors: Vanhecke F. , Heremans K. , Mesmaeker A. Kirsch‐De , Jacquet L. , Masschelein A. 
Published: May 2005

AbstractThe surface‐enhanced resonance Raman (SERR) spectra of several monometallic and polymetallic complexes of Ru(II) with 2.2′‐bipyridine (bpy) and the trichelating 1,4,5,8,9,12‐hexaazatriphenylene (HAT) on silver sols are reported. The SERR technique allows a vibrational study of these compounds, which is not always possible in solution because of their strong luminescence. Geometric and spectroscopic factors determine the features of the SERR spectra. It is suggested that the wavelength dependence of the SERR spectra is determined by selection rules similar to those proposed for surface‐enhanced Raman scattering.
Comparative study of aclacinomycin versus adriamycin by means of resonance Raman spectroscopy
Authors: Nonaka Yasuomi , Tsuboi Masamichi , Nakamoto Kazuo 
Published: May 2005

AbstractResonance Raman spectra of adriamycin and aclacinomycin A were examined in their H2O and D2O solutions. These spectra appear totally different from each other, but the differences are found to be similar to those between 1,4‐ and 1,8‐dihydroxyanthraquinone, which are considered to be model chromophores of adriamycin and aclacinomycin, respectively. Surface‐enhanced resonance Raman spectra of these two drugs were also compared by the use of silver sols. The effects of DNA binding on the resonance Raman spectra are also significantly different for these two drugs. Adriamycin was found to be intercalated in the CpG (or GpC) site of the DNA duplex, but aclacinomycin in the TpA (or ApT) site. Most of the differences in the spectra and sequence specificity are explained in terms of the molecular structures of their chromophores, i.e. in the adriamycin chromophore (1,4‐dihydroxyanthraquinone) two OH groups are hydrogen bonded to different CO groups, whereas in the aclacinomycin chromophore (1,8‐dihydroxyanthraquinone) two OH groups form hydrogen bonds with the same CO group, leaving the other CO group free from any intramolecular hydrogen bonding.
Application of Raman spectroscopy in recognition of the two crystalline forms of terephthalic acid
Authors: Colombo L. , Volovšek V. , Furić K. , Durig J. R. 
Published: May 2005

AbstractSolid terephthalic acid exists in two polymorphic forms with both structures being triclinic. Raman spectroscopic studies have been made in order to recognize the presence of form I and/or form II in the sample.
Raman bands of N‐deuterated histidinium as markers of conformation and hydrogen bonding
Authors: Takeuchi Hideo , Kimura Yukiko , Koitabashi Ikuyo , Harada Issei 
Published: May 2005

AbstractRaman spectra were measured for five crystals containing N‐deuterated histidinium and their C2‐deuterated analogues. The spectra showed strong bands assignable to the C4C5 stretching mode, ν(C4C5), and the NτC2Nπ symmetric stretching mode, ν(NτC2Nπ), characteristic of the N‐deuterated imidazolium ring. By comparison with the crystal structures, the ν(C4C5) and ν(NτC2Nπ) frequencies are found to increase linearly with increase of the absolute value of the CαCβC4C5 torsional angle (χ2, 1), which determines the ring orientation relative to the amino acid backbone. Exceptionally, the ν(NτC2Nπ) frequency of the C2‐deuterated imidazolium ring does not depend on the conformation but shows a correlation with the ND stretching frequency of the ring, indicating that ν(NτC2Nπ) becomes a marker of hydrogen‐bonding strength when the imidazolium ring is deuterated at C2. These marker bands may be useful in studying the conformation and hydrogen‐bonding states of histidine residues in proteins and peptides.
Use of Q‐switched lasers in near‐infrared fourier transform Raman spectroscopy. I
Authors: Cutler David J. , Mould Henry M. , Bennett Bob , Turner Andrew J. 
Published: May 2005

AbstractIt is demonstrated that the use of pulsed lasers in near‐infrared Fourier transform Raman spectroscopy can give a significant increase in signal‐to‐noise ratios over continuous‐wave measurements made using the same average laser power. It is also shown that when a thermal (or other relatively long‐lived) background is present, the use of pulsed excitation can greatly reduce its effect and, under certain circumstances, can allow it to be subtracted completely.
Raman and infrared spectra of NiI2 · 6H2O
Authors: Cariati F. , Bruni S. , Martini M. , Spinolo G. 
Published: May 2005

AbstractThe polarized Raman spectra and infrared absorption spectra of NiI2 · 6H2O were measured in the 50–4000 cm−1 region at low temperatures. Deuterated samples were also studied and gave results which were useful for interpretation purposes. Satisfactory assignments of water internal and external modes and lattice vibrations were made. The vibrational analysis, on the basis of which the assignments were made, was related to the D34 factor group; however, the symmetry of the Raman‐active bands, as deduced from polarized spectra, suggests that for water librations the C2h factor group provides a better basis for interpretation.
Raman spectrum of CuSO4 · 5H2O single crystal
Authors: Liu D. , Ullman F. G. 
Published: May 2005

AbstractThe Raman spectrum of a CuSO4 · 5H2O single crystal was measured at 95 K. The assignment of the internal modes of the molecular complex Cu2+ (H2O)4 and of differently bonded water molecules is discussed.
Raman spectra of polymorphs of isotactic polypropylene
Authors: Chalmers J. M. , Edwards H. G. M. , Lees J. S. , Long D. A. , Mackenzie M. W. , Willis H. A. 
Published: May 2005

AbstractRaman spectra of the α‐, β‐, γ‐ and smectic polymorphs of isotactic polypropylene were recorded at 298 and 16.5 K. At 298 K the spectra of the polymorphs were very similar except in the antisymmetric CH stretching region. However, at 16 K the Raman spectra of the polymorphs show different features in several wavenumber shift regions. Comparisons are made with infrared spectra recorded at 298 and 100 K and interpretations are made on the basis of non‐equivalent sites in the monoclinic unit cells.
Application of surface‐enhanced Raman spectroscopy to biological systems
Authors: Cotton Therese M. , Kim Jae‐Ho , Chumanov George D. 
Published: May 2005

AbstractThis review summarizes the literature relating to the application of surface‐enhanced Raman scattering (SERS) and surface‐enhanced resonance Raman scattering (SERRS) techniques to the study of biological molecules. The emphasis is on publications that have appeared during the period from 1985 to 1991. The review is divided into six major parts. First, a brief overview of the current understanding of the mechanistic aspects of SERS/SERRS is given, with an emphasis on the relationship between theoretical predictions and experimental results. The most common experimental systems (colloids, metal island films, and electrodes) are described. Studies of biological systems are described in the second (small molecules), third (DNA and proteins) and fourth (membranes proteins and membrane preparations) sections. In the fifth or conclusion section, the potential use of SERS or SERRS as a method for obtaining spectra of native biological molecules is evaluated. Finally, the sixth section describes advances in Raman instrumentation in terms of their possible impact on future applications of SERS/SERRS techniques to biological molecules.
Vibrational study of (CH3NH3)2ZnCl4 and (CH3 NH3)2ZnBr4
Authors: Srinivasan T. K. K. , Mylrajan M. , Rao J. B. Srinivasa 
Published: May 2005

AbstractRaman and infrared spectral studies of (CH3NH3)2ZnCl4 and (CH3NH3)2ZnBr4 were carried out at 90, 300 and 443 K. The vibrational spectra were analysed on the basis of the C space group. Assignments were also made by comparison with the spectra of the N‐deuterated analogues. The non‐degenerate CN stretching mode showed splitting due to non‐equivalent cations in the lattice as opposed to layer type of perovskites. Above 426 K, these splittings are absent, indicating the removal of non‐equivalence. The cation bands are broad above 426 K, indicating the reorientational motion of the cations.
SERS of cytosine and its methylated derivatives on metal colloids
Authors: Śanchez‐Cortés S. , Garcia‐Ramos J. V. 
Published: May 2005

AbstractSERS spectra of cytosine, 1‐methylcytosine, 5‐methylcytosine and 1,5‐dimethylcytosine on silver and on copper colloids are reported. A study of the influence of pH on the normal Raman spectra of these compounds was made in order to understand better the behaviour of these molecules on metal surfaces. The results obtained indicate remarkable changes in the type of adsorbate—metal interactions depending on the metal used as the SERS support. These interactions are also influenced by the presence of methyl groups in the cytosine molecule.
Effect of temperature on the local structure in liquid benzene. I—Raman spectra of the depolarized Rayleigh wing
Authors: Pinan‐Lucarre J. P. , Loisel J. , Berreby L. , Dayan E. , Dervil E. 
Published: May 2005

AbstractThe behaviour of (i) the Raman integrated intensity of the v16 (405 cm−1) vibrational band and (ii) the depolarized Rayleigh wing of benzene over its whole liquid range as a function of temperature was examined. In case (i) the variation obtained seems to be monotonic, but in case (ii) a change in the intensity variation is observed around 37–40°C. This change may be attributed to a modification of symmetry in the local molecular environment of a given benzene molecule.
Characterization of porous titania glass: Raman, x‐ray diffraction and x‐ray photoelectron spectroscopic studies
Authors: Chee Yee Hong , Cooney R. P. , Howe R. F. , van der Heide P. A. W. 
Published: May 2005

AbstractPorous titania glass (PTG) was characterized by laser Raman spectroscopy, x‐ray diffraction, ultraviolet‐visible spectroscopy, photoelectron spectroscopy and transmission electron microscopy. PTG after annealing at 573 K contains amorphous titania and anatase. Heating in air above 693 K causes transformation into the rutile phase. The low transition temperature is attributed to the highly defective nature of PTG.
Solid‐state infrared and Raman spectra of carbonyl‐tert‐butyl isocyanide complexes of chromium(0), molybdenum(0) and tungsten(0), M(CO)6−n(CNBu‐t)n (n = 1–3)
Authors: Li Hongqi , Butler Ian S. , Uhm Haewon L. 
Published: May 2005

AbstractVibrational assignments are reported for the room‐temperature IR and Raman spectra of three series of solid group 6B metal(0) carbonyl‐tert‐butyl isocyanide complexes of the general formula M(CO)6‐n(CNBu‐t)n, where M = Cr, Mo, W and n = 1–3. Sequential replacement of the CO groups by CNBu‐t leads to gradual shifts of the ν(CN) bands to higher energies, while the ν(CO) bands shift to lower energies. These results provide good evidence for the stronger σ‐donor and weaker π‐acceptor capacities of the CNBu‐t ligand compared with those of CO.