bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman and infrared spectra of ferroelectric (CH3NH2CH2COO)3 CaCl2
Authors: Acharya P. Kumara , Narayanan P. S. 
Published: May 2005

AbstractRaman spectrum of Tris‐sarcosine Calcium chloride has been recorded both in the para and ferroelectric phases using λ = 2537 Å of mercury as exciting radiation. The infrared absorption spectrum has been recorded both above and below the Curie temperature, in the region 400 to 4000 cm−1. From the observed splitting of the infrared bands it is concluded that the second order ferroelectric phase transition at 127K is due to a dynamical ordering of sarcosine molecules which exist in zwitteron configuration. Raman spectrum shows eight lattice lines which do not exhibit any anomaly as the crystal undergoes phase transition.
Circularly polarized Raman spectroscopy: Direct determination of antisymmetric scattering in the resonance Raman spectrum of ferrocytochrome c
Authors: Nestro James , Spiro Thomas G. 
Published: May 2005

AbstractAn apparatus is described for measuring Raman backscattering with both linearly and circularly polarized light. All four polarization components, parallel, perpendicular, corotating and contrarotating, can be directly compared and used to determine the relative magnitudes of the three invariants of the non‐symmetric Raman tensor for randomly oriented molecules. The method has been applied to the resonance Raman spectrum of ferrocytochrome c. Antisymmetric scattering, previously detected through anomalous depolarization ratios, has been confirmed by direct measurement of the antisymmetric tensor invariant. In addition to the four anomalously polarized bands, two bands with normal polarizations have been shown to exhibit significant antisymmetric scattering. This result implies a reduction from four‐hold symmetry for the heme chromosphere.
Raman and infrared spectra of BaCrO4 and BaSeO4
Authors: Scheuermann W. , Schutte C. J. H. 
Published: May 2005

AbstractThe vibrational spectra of BaCrO4 and BaSeO4 were recorded at 295K and 77K. The Raman spectrum of BaCrO4 melt was also recorded, using the energy of an argon laser beam as a heat source. The spectra of the two compounds proved to be remarkably different, although they belong to the same space group and are said to have the same structure. Evidence was found that the principles of mutual exclusion and inversion doubling are effective in both compounds; these are due to rather strong interionic coupling. An assignment could only be made for the most prominent bands.
Raman spectra and crystal structure of sodium periodates
Authors: Poulet H. , Mathieu J. P. 
Published: May 2005

AbstractThe complete set of fundamental frequencies of NaIO4 (tetragonal crystals) has been determined. Raman spectra of NaIO4, 3H2O (trigonal crystals) show that the structure proposed by Burgers is erroneous; a more plausible one is suggested. The angular dispersion of the polar phonons was also studied.
Raman spectra of orthorhombic sulfate single crystals I: K2SO4, Rb2SO4, Cs2SO4 and Tl2SO4
Authors: Montero S. , Schmölz R. , Haussühl S. 
Published: May 2005

AbstractIn order to confirm the assignment of the Raman active internal modes of K2SO4 and structurally related crystals, the Raman spectra of oriented cyrstals have been recorded. Using the relative integrated intensities of the bands as data, the transferability of the Raman tensors of the free SO ion to the crystals was investigated with, in general, good agreement between the calculated and measured intensity distribution. A linear dependence between the frequencies of the internal modes of the K2SO4, Rb2SO4 and Cs2SO4 crystals and the electronegativity of the cations could be observed. Also, a brief discussion about the nature of the lattice modes of these crystals is included.
Resonance Raman spectra of protohemin and protohemin‐imidazole complex
Authors: Verma A. L. , Bernstein H. J. 
Published: May 2005

AbstractResonance Raman spectra of aqueous solutions of protohemin and its complex with imidazole have been obtained using several exciting lines from Ar+ and HeCd lasers. The effects of different axial ligands to iron in hemin are reflected in the resonance Raman spectra of their respective complexes. Within experimental limits, hemin does not show any anomalously polarized bands (Q1 > ¾) while its complex with imidazole shows several such bands when excitation is in the α and β absorption regions. When excitation is in the Soret region, a polarized band ∼ 1500 cm−1 appears in the spectra of hemin‐imidazole complex and heme proteins. It is proposed as a spin state marker as well as to characterize the position of the iron ion relative to the porphyrin plane.Excitation profiles for some of the bands of hemin confirm the assigment of the α band near 5300 Å in the unresolved visible absorption spectrum.
Vibrational spectra and structure of crystalline 1–3 dinitrobenzene
Authors: Bobrov A. V. , Mathieu J. P. , Poulet H. 
Published: May 2005

AbstractThe analysis of Raman and infrared spectra of the H and D forms of m dinitrobenzene in solution and in the cyrstalline state allows a tentative assignment of most of the observed bands. It gives no evidence for intermolecular dynamical coupling or for hydrogen bonding and favours Archer's structure. No angular dispersion is noticeable, but polaritons are observed.
Gas phase Raman spectra of cyclopropane‐h6 and cyclopropane‐d6
Authors: Daunt Stephen J. , Shurvell H. F. 
Published: May 2005

AbstractThe gas phase Raman spectra of normal and perdeutero‐cyclopropane have been recorded at medium resolution. The band contours of the E′ and E″ degenerate modes have been observed and computer simulation of them has allowed determination of the ζiz values. This analysis was possible for ν9, ν11, ν12, ν13, and ν14 of C3H6 and for ν9, ν10, ν11, ν12, ν13, and ν14 of C3D6. The gas phase spectrum of C3D6 is reported for the first time and assigned. The agreement between our results and the IR data on the E′ modes is good. Predicted parameters for the E″ modes from force field calculations are also in good agreement with the data reported here.
Resonance Raman effect of octahedral complex ions, PtBr and PtI
Authors: Hamaguchi Hiro‐O , Harada Issei , Shimanouchi Takehiko 
Published: May 2005

AbstractThe rigorous resonance Raman effect was observed for the octahedral PtBr and PtI ions. The enhancement of the Raman intensity occurred for the totally symmetric ν1 band and for the non‐totally symmetric ν2 band simultaneously in both cases of the two ions. The overtone bands of ν2 appeared in the spectra in addition to the ordinary long overtone progression of the ν2 vibration. The results are discussed in relation to the two closely lying electronic levels of the ions.
Novel Raman spectra of metal surfaces
Authors: Linnett J. W. , Barron L. D. , Bhattacharya A. K. 
Published: May 2005

AbstractA series of very sharp bands at ca. 50 cm−1 have been observed in the low frequency surface Raman spectra of tungsten and nickel in air and in vacuum (10−5 torr) which probably originate in a surface layer of adsorbed molecules.
Resonance Raman studies of 1,2,3,4,5,6,7,8‐octamethylporphin, 1,3,5,7‐tetramethylporphin, and mesotetraphenylporphin and its Ni‐, Cu‐, and Pd‐chelates
Authors: Mendelsohn R. , Sunder S. , Bernstein H. J. 
Published: May 2005

AbstractResonance Raman spectra are reported for 1,2,3,4,5,6,7,8‐octamethylporphin, 1,3,5,7‐tetramethylporphin and mesotetraphenylporphin and its Ni‐, Cu‐, and Pd‐chelates. Comparison of infrared and Raman data for the non‐metallo compounds provides evidence that mesotetraphenylporphin loses its centre of symmetry in the solid state while the other two molecules retain theirs.Depolarization ratio measurements for Ni‐tetraphenylporhin in CS2 solution reveal the presence of several anomalously polarized vibrations (ϱ > ¾). Evidence is presented to show that the symmetry of the molecule in solution has been reduced from D4h.
Resonance Raman scattering from isotopically pure and natural bromine vapor
Authors: Baierl P. , Kiefer W. 
Published: May 2005

AbstractWe have recorded high‐resolution resonance Raman spectra of the bromine molecule in its natural abundance and as pure isotopic molecules 79Br2 and 81Br2 with excitation by light which is in resonance with the continuum of the B(3Π)‐state. The observed spectra are characterized by a progression of vibrational lines up to the tenth harmonic. These lines display complex structure which can be explained in terms of Q branches, S band heads, unresolved O branches and vibrational ‘hot’ bands. The assignment of all observed lines is based on Fortrat diagrams which have been calculated by using spectroscopic constants derived from high resolution absorption spectra and on depolarization measurements. The vibrational constants ωe, ωexe and ωeye and the rotational constants Be and αe for the X (1Σ)‐state of bromine were determined independently from the Raman spectra. Variations of the spectral band shape of the fundamental and the overtones were observed using five different exciting lines of the argon ion laser. The band shapes were also studied while changing the laser power which affects the spectroscopic temperature. A qualitative discussion of the observed changes is given.
Raman spectroscopy study of powdered [Ni(NH3)6] X2 compounds
Authors: Janik J. M. , Janik J. A. , Pytasz G. , Sokołowski J. 
Published: May 2005

AbstractTen out of eleven Raman active modes were detected in [Ni(NH3)6] X2 powders, apart from internal modes of the X− ions. The Raman active lattice mode happens to agree fairly well with the predictions of a model based on the electrostatic potential field of point charges. The X = Cl compound showed evidence of losing ammonia during irradiation with the laser beam. Two modes (the NNiN angle deformation and the lattice vibration) are especially sensitive to the NH3− vacancies thus created.
Raman and infrared spectra of K2PtCl6:Ir4+ crystals
Authors: Kuan T. S. 
Published: May 2005

AbstractThe low temperature Raman and far‐infrared (IR) spectra of solution‐grown crystals of K2PtCl6:Ir4+ have been studied. In addition to the strong absorptions of the host compound, a number of weak features were observed. The Raman band at 278 cm−1 has been assigned to ν2(Eg) of IrCl. An IR‐ and Raman‐active band, observed at 236 cm−1 when K2IrBr6 was used as the dopant, has been assigned to ν(Pt‐Br), A1g′ of [PtCl4Br2]2−. The symmetry of the host compound was lowered by the presence of the dopant ions, resulting in a splitting of some of the IR‐active degenerate modes. Preliminary Raman experiments with K2PtCl6:Os4+ indicated that ν2 of OsCl was at 271 cm−1.
A new technique in matrix isolation spectroscopy: Infra‐red and Raman spectra from the self‐same matrix
Authors: Grzybowski J. M. , Carr B. R. , Chadwick B. M. , Cobbold D. G. , Long D. A. 
Published: May 2005

AbstractThe design of a single experimental system which allows for the first time, the acquisition of the infra‐red and the Raman spectra from the self‐same matrix is reported. To illustrate the performance of the system the infra‐red and Raman spectra of the matrix systems ICN/N2 (M/S = 400) and S2Br2/Ar (M/S ⋍ 1000) are presented and discussed briefly.
Resonance Raman spectra of a peroxotitanium (IV) cation in aqueous solution
Authors: Peruzzo V. , Hester R. E. 
Published: May 2005

AbstractThe resonance Raman spectrum of a Ti(IV)H2O2 complex in acidic (H2SO4) aqueous solution is shown to consist of bands at 623, 1236 and 1852 cm−1. Excitation with three different lines of an argon ion laser showed the higher two Raman bands to be overtones of the 623 cm−1 fundamental, this arising from the symmetric TiO stretching mode, ν2, of a TiO2 species with C2ν symmetry. No ν(O  O) resonance enhancement was observed. Depolarization data and Raman intensity – molar absorbtivity relationships are established.
Resonance Raman intensities of 1,1,4,4‐tetrachloro‐1,3‐butadiene and normal modes of vibrations in its electronic ground and excited states
Authors: Suzuki Ei‐Ichiro , Hamaguchi Hiro‐O , Harada Issei , Matsuura Hiroatsu , Shimanouchi Takehiko 
Published: May 2005

AbstractThe relative intensities of the resonance‐enhanced Raman bands and the solvent effect on these intensities were quantitatively studied for 1,1,4,4‐tetrachloro‐1,3‐butadiene. The results were interpreted on the basis of the normal coordinate treatment in combination with Albrecht's theory of Raman intensities. The vibrational structure of the electronic absorption band was interpreted simultaneously. Information on the molecular structure and normal modes of vibrations in the electronic excited state was obtained. The importance of the normal coordinate treatment in the analysis of the resonance Raman spectra is emphasized.
Depolarization dispersion of a fundamental line of a totally symmetric vibration in resonance Raman scattering
Authors: Zgierski Marek Z. 
Published: May 2005

AbstractVibronic coupling of the Herzberg‐Teller type is discussed as a possible source of the depolarization dispersion of a fundamental line of a totally symmetric vibration in resonance Raman scattering (RRS). Two cases are discussed separately. The first case concerns RRS from an electronic state that borrows part of its intensity from a non‐overlapping electronic state of different symmetry. In this case the depolarization ratio of the fundamental line for right angle scattering linearly polarized light can vary between the limits 1/8 and 3/4. The second case arises when part of the intensity is borrowed from an electronic state of the same symmetry but with a transition moment non‐parallel to that of the resonant state. Such a situation can occur in molecules with a symmetry corresponding to one of the following point groups: C1, Ci, C2, Cs, C1h, C2h, S2. In this situation the depolarization ratio ρl can vary between the limits 1/8 and. In both cases the amplitude of the variations of ρl depends on the damping constant. In the second case the value of the displacement parameter of a totally symmetric mode has a major influence on the range of change of ρl. Both cases show prominent resonance‐antiresonance coincidences between depolarization dispersions and excitation profiles, which has been previously predicted for non‐totally symmetric modes, and for molecular dimers. It is pointed out that the depolarization ratio in the preresonance region is very sensitive to vibronic coupling and can serve as a probe of such coupling.
Raman spectra of cubic Cs2NaMCI6 rare earth compounds
Authors: Haley L. V. , Koningstein J. A. 
Published: May 2005

AbstractThe Raman spectra of the cubic compounds Cs2NaMCl6 with (M = Eu+3, Tb+3, Er+3 and Tm+3) has been observed in the region 25 cm−1 < Δν < 300 cm−1. The experimental results are in complete agreement with the factor group analysis which predicts the four vibrational Raman active bands A1g, Eg and 2T2g. Also, the absence of electronic Raman bands is discussed.
The vibrational spectra of the metalloporphins: A normal coordinate analysis of the planar vibrations in the Cu‐chelates of porphin, porphin‐d4 (meso), 1:3:5:7‐tetramethyl porphin and 1:2:3:4:5:6:7:8‐octamethyl porphin
Authors: Sunder S. , Bernstein H. J. 
Published: May 2005

AbstractNormal coordinate calculations have been carried out for all the planar vibrations of Cuporphin, Cu‐porphin‐d4 (meso), Cu‐1:2:3:4:5:6:7:8‐octamethyl porphin and Cu‐1:3:5:7‐tetramethyl porphin. A method is presented to obtain the skeleton deformation and the CC stretching force constants in large organic molecules with delocalized double bonds from the bond length values. This method enabled a satisfactory calculation of 160 observed frequencies in the resonance Raman and infrared spectra of the four Cu‐porphins by using a valance force field containing only 12 independent parameters. Assignments for some of the stronger bands in the resonance Raman spectra of heme proteins and metallo‐porphins are discussed.
An analytic model of resonance Raman scattering by a continuum
Authors: Laplante Jean Pierre , Bandrauk André D. 
Published: May 2005

AbstractAn analytic expression is obtained for resonant photon scattering by a molecular electronic continuum. Using the model of linear potentials, it is shown that all relevant cross‐sections reduce to the linear potential Green's function. Rayleigh and Raman scattering are examined as a function of incident photon energy and also as a function of vibrational excitation.
Study of the ν1 Raman linewidth of SO in acidic solutions
Authors: Ikawa S. , Yamada M. , Kimura M. 
Published: May 2005

AbstractThe ν1 Raman linewidths of SO in NH4HSO4, NH4HSO4 + HCl and H2SO4 aqueous solutions were estimated by resolving the observed bands into several components with a Voigt profile. From their concentration dependence, the rate constants of proton transfer were estimated to be 4.5 × 1011 M−1s−1 consistently for the three kinds of acidic solutions.
Experimental study on the resonance Raman effect and absorption spectrum of ClO2 in solution
Authors: Eysel H. H. , Bernstein H. J. 
Published: May 2005

AbstractChlorine dioxide dissolved in inert solvents [CCl4 and CFCl3 (Freon ll)] has been investigated by means of u.v./visual‐absorption spectroscopy and Raman‐spectroscopy. The vibrational constants for the 2B1, ground state and the2A2 excited state have been redetermined. While the ground state constants are in good agreement with gas state data, the excited state constants differ considerably from previous data. The Raman excitation profile is given for the v1 fundamental and its first harmonic in the region of excitation from 6471 Å to 4579 Å. Dispersion of the depolarization ratio (ρ = 0.16(6471 Å); ρ = 0.23(4765 Å))shows the contribution of two electronic state to the polarizability tensor. Expermental evidence is given that the decomposition of ClO2 in solution is not sensitive to vislble light.
Force constants and bond polarizability derivatives of some XY4 square‐planar type ions
Authors: Pandey A. N. , Sharma D. K. , Verma U. P. , Kumar V. 
Published: May 2005

AbstractThe general valence force field has been employed to evaluate force constants for some square‐planar type anions e.g. XY (X = Pd, Pt or Au; Y = Cl or Br; n = 1 or 2) and ICl. Bond polarizability derivatives, from Lippincott and Nagarajan, and Long and Plane, have been evaluated and compared with the experimental results. Theoretically determined bond orders have also been compared with experimentally estimated values.
Spectres Raman d'un Monocristal de As2O3, SO3 et Calcul du Champ de Force
Authors: Mercier R. , Sourisseau C. , Lucazeau G. 
Published: May 2005

AbstractThe polarized Raman spectra of a single crystal of As2O3, SO3, along with the infrared spectra of this compound in the polycrystalline state have been investigated at 30 K and 300 K in the 20–4000 cm−1 range. The dependance of the frequency shift of polar vibrations with the geometry of the Raman experiments has also been studied. An assignment in terms of symmetry species is proposed for 49 of the 51 expected active modes. A normal coordinate calculation using a valence force field has been performed for the principal vibrations (k ⋍ 0) of the crystal. The good agreement between observed and calculated frequencies shows that long range forces are negligible compared to internal valence forces. There are two different SO bonds characterized by stretching force constants of 9.1 and 5.2 mdyn Å−1 and SO bond lengths have been estimated equal to 1.44 and 1.56 Å respectively, by using an empirical correlation. The AsO stretching force constants of the OAsOAs…︁ chains and of the bonds linking As and SO4 groups are similar: 2.0 and 1.9 mdyn Å−1 respectively. Therefore the crystal is not an ionic sulphate compound.
Liaisons Métal–Métal et Spectres Raman de Préresonance du Compose Co4(CO)12
Authors: Sourisseau Claude 
Published: May 2005

AbstractRaman spectra of Co4(CO)12 compound in heptane solutions have been investigated in the cobalt‐cobalt bond stretching vibrations range (250–100 cm−1). For comparison, the i.r. spectrum (300–30 cm−1) of this compound in the solid state has been recorded. Using the model of one M′M3 cage, the valence force constants of cobalt‐cobalt bonds have been calculated; the force constants are compared with those of RhRh and IrIr bonds in Rh4(CO)12 and Ir4(CO)12 clusters. The compound Co4(CO)12 has also been found to display preresonance Raman spectra when irradiated with 6471, 5145, 4965, 4880, 4579 and 4545 Å excitations. This preresonance effect has been analysed by the relative intensities measurements of the totally symmetric stretching bands.
Determination of derivatives of the polarizability anisotropy in a diatomic molecule from relative Raman intensities
Authors: Buckingham A. D. , Szabo Attila 
Published: May 2005

AbstractRelative intensities of the S(J) and O(J) branch lines in the fundamental and overtone bands of the vibration‐rotation Raman spectrum of a linear molecule are shown to be capable of yielding the magnitude and sign of the first and second derivatives of the polarizability anisotropy, (α∥−α⊥)′e and (α∥−α⊥)″e in relation to the equilibrium anisotropy (α∥−α⊥)e. The theory is applied to hydrogen and nitrogen.
Resonance Raman scattering from triply degenerate singlet electronic states
Authors: Pawlikowski M. , Zgierski M. Z. 
Published: May 2005

AbstractExcitation profiles and depolarization dispersion curves for e and t vibrations that are active in the T × e and T × t Jahn‐Teller coupling for molecules with a non‐degenerate electronic ground state are discussed.
Raman study of the rotational isomers of bicyclopropyl and vinylcyclopropane
Authors: Salares V. R. , Murphy W. F. , Bernstein H. J. 
Published: May 2005

AbstractThe Raman spectra of bicyclopropyl and vinylcyclopropane were studied in the solid, liquid and vapor phases in an attempt to identify their rotational isomers and to measure their enthalpy differences. For bicyclopropyl, the presence of the s‐trans and gauche isomers in the liquid and vapor phases has been confirmed. The present measurements show that the gauche isomer is more stable in both the vapor and liquid, by 91±28 cal mol−1 in the vapor and by 188±10 cal mol−1 in the liquid. For vinylcyclopropane, features due to only two conformers could be identified in the liquid and vapor spectra. In the vapor the predominant isomer, previously identified as the s‐trans rotamer,9 was found to be more stable by 1.1±0.1 kcal mol−1.
The pure rotational Raman spectrum of sulphur trioxide
Authors: Brassington N. J. , Edwards H. G. M. , Farwell D. W. , Long D. A. , Mansour H. R. 
Published: May 2005

AbstractThe pure rotational Raman spectrum of sulphur trioxide in the vapour phase at 333K has been obtained and analysed for the first time. The following rotational constants and bond length were determined:

This r0 value agrees to within the sum of one standard deviation of the experimental errors with the value obtained from an analysis of the vibration–rotational infrared spectrum of the 2ν3 band.
Spectroscopic study of monosubstituted amides. VII—low frequency Raman spectra of crystallized N‐methylacetamide
Authors: Fillaux F. , Baron M. H. , De Loze C. , Sagon G. 
Published: May 2005

AbstractThe Raman spectra of 10 isotopic species of polycrystalline NMA were recorded at 35 K between 6 and 200 cm−1. Below 110 cm−1 at least 8 transitions are observed which are mainly due to external modes. Bands located between 110 and 170 cm−1 show unexpected isotopic effects and are interpreted taking into account IR and NIS spectra. A new internal torsional mode around the bond is proposed. The corresponding potential function involves two minima (Δω = ± 10°) separated by a weak barrier (∼600 cal/mole) indicating a nonplanar molecular skeleton.