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1.
Hui Wang Yufang Wang Xuewei Cao Min Feng Guoxiang Lan 《Journal of Raman spectroscopy : JRS》2009,40(12):1791-1796
The phonon dispersions of graphene and graphene layers are theoretically investigated within fifth‐nearest‐neighbor force‐constant approach. Based on their symmetry groups, the number of Raman‐ and infrared‐active modes at the Γ point is given. Interatomic force constants are recalculated by fitting them to experimental phonon energy dispersion curves. Wavenumbers of optically active modes are presented as a function of number of layers (n). Our calculated results reproduce well the experimental data of G peak for graphene (1587 cm−1) and graphite (1581.6 cm−1) and clearly give the relation that ωG = 1581.6 + 11/(1 + n1.6). Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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The infrared and Raman spectra of barium oxalate hemihydrate, BaC2O4 · 0.5H2O, were recorded and discussed on the basis of their structural peculiarities and in comparison with the spectra of the previously investigated calcium and strontium oxalates. 相似文献
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Abstract Coherent anti-Stokes Raman scattering (CARS) and spontaneous Raman spectroscopy have been used to obtain vibrational spectra of shock-compressed and static high-pressure fluid nitrogen, respectively. Vibrational frequencies were obtained from the CARS data using a semiclassical model for these spectra. Spontaneous Raman vibrational frequencies were determined by fitting data using a Lorentz shape line. A functional form was found for the dependence of the vibrational frequency on pressure and temperature to 40 GPa and 5000 K, respectively. The result is compared to a recent theoretical model. 相似文献
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Nancy Mancilla Maria C. D'Antonio Ana C. Gonzlez‐Bar Enrique J. Baran 《Journal of Raman spectroscopy : JRS》2009,40(12):2050-2052
The infrared and Raman spectra of anhydrous lead oxalate (PbC2O4) were recorded and discussed on the basis of its structural peculiarities. Some comparisons with other previously investigated metallic oxalates were made. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Infrared and Raman spectra of seven new metal (II) 3,4-lutidine tetracyanonickelate complexes, M(3,4 L)2 Ni(CN)4 [where 3,4 L = 3,4 - dimethyl-pyridine or 3,4-lutidine; M = Mn, Fe, Co, Zn, Ni, Cu or Cd] (abbreviated to M - Ni - 3,4 L) have been investigated. Spectroscopic and magnetic susceptibility measurements indicate that the compounds have the structure of Hofmann-type complexes. The copper complex has spectral features different from the other compounds. 相似文献
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Their and Raman spectra of molybdenum trioxide—monohydrate are studied assuming an effective tetrahedral Mo-O coordination and
isolated water molecules, although the crystallographic coordination is six-fold with two long Mo-O distances. Based onCt symmetry, the group theoretical analysis has been carried out and a vibrational assignment is proposed. The nature of hydrogen
bonding and the librational modes of water molecules are discussed. The factor group splitting forv3, the asymmetric stretching mode of MoO4
= ion, is large indicating strong interchain coupling. 相似文献
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Raman, infrared and energy dispersive X-ray spectra of monazites have been measured and discussed. The result shows that the mineral is enriched in cerium, lanthanum,neodymium and praseodymium (Ce>La>Nd>Pr), The monazites have marked spectral characteristics, especially their v1, V3 Raman bands and v1, v4 infrared absorption bands. The characteristics can distinguish between monazite and other phosphate minerals. In addition, based on EDS and infrared absorption spectra, a small amount of fluoro-carbonate is found in the monazites. 相似文献
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Thiago O. Mendes Georgia M. A. Junqueira Brenda L. S. Porto Charles D. Brito Fernando Sato Marcone A. L. de Oliveira Virgilio Anjos Maria J. V. Bell 《Journal of Raman spectroscopy : JRS》2016,47(6):692-698
This paper presents a systematic analysis of the infrared absorption spectra and Raman scattering of the triacylglycerol molecule predominant in raw bovine milk. Gas chromatography measurements were also performed and revealed the palmitic, stearic, and oleic acids as the most predominant fatty acids in the composition of milk. Based on the gas chromatography results, infrared, and Raman spectra of the triacylglycerol with this combination of fatty acids were simulated. The theoretical spectra were compared with the experimental ones of milk fat and fluid raw milk. Assignment of bands of milk fat was proposed, which can be used for a quality monitoring of the product. We also performed a multivariate model of partial least squares from samples of fluid milk with different concentrations of fat. As a result, the most important variables in the projection were selected as vibrational markers for quality monitoring and quantifying of this important constituent of milk. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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The infrared and laser Raman spectra of 2, 3 dichloro aniline and 2, 6 dichloro aniline have been recorded. The vibrational
spectra have been analysed assumingC
s andC
2v
point groups for 2, 3 dichloro aniline and 2, 6 dichloro aniline respectively. Assignments for fundamental vibrations, combination
and overtone frequencies and internal modes of vibration of amino group have been proposed. 相似文献
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Infrared and Raman spectra were obtained for 2,3-dimethyl-1-butene. The spectra showed the presence of two stable conformations. Vibrational assignments were made for both conformers with the aid of normal coordinate calculations. Values for the force constants that were obtained will be used in the future as the initial values for other substituted 1-alkenes, such as 2-isopropyl-3-methyl-1-butene. 相似文献
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Nancy Mancilla Valeria Caliva Maria C. D'Antonio Ana C. Gonzlez‐Bar Enrique J. Baran 《Journal of Raman spectroscopy : JRS》2009,40(8):915-920
The three known hydrates of manganese(II) oxalate, α‐MnC2O4 · 2H2O, γ‐MnC2O4 · 2H2O and MnC2O4 · 3H2O were synthesized by known procedures and characterized by X‐ray powder diffractometry. Their infrared (IR) and Raman spectra were recorded and discussed on the basis of its structural peculiarities allowing to establish some interesting relations between them and with other, previously investigated, oxalate complexes. The IR spectra of partially deuterated samples of α‐MnC2O4 · 2H2O were also discussed, reinforcing some of the performed assignments. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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The i-r. spectra of thiazole-2-carboxylic acid and thiazole-2-carboxylate ion as CsI pellets and Nujol mull as well as Raman spectrum of an aqueous solution of the salt have been investigated. Most vibrations have been assigned on the basis of group frequencies and by correlation between the spectra of both molecules. The -COOH characteristic vibrations have been assigned as vibrations of the intermolecularly associated species. 相似文献
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Polaprezinc, the Zn(II) complex of the dipeptide carnosine (β‐alanyl histidine) presents an interesting biological and pharmacological activity, specially as an anti‐ulcer agent. The infrared and Raman spectra of this compound were recorded and briefly discussed. Some comparisons were made with related complexes and with free carnosine. The results confirm the coordination environment of the Zn(II) cation, constituted by the terminal amino N‐atom, the deprotonated amide N‐atom and one carboxylate oxygen of one dipeptide molecule and the N‐atom of the imidazole moiety of a second carnosine molecule. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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J. Santos Coelho W. Paraguassu M. Maczka A. G. Souza Filho P.T.C. Freire J. Mendes Filho J. Hanuza 《Journal of Raman spectroscopy : JRS》2009,40(9):1150-1157
Hexagonal bronzes and valence‐balanced hexatungstates (VBHT) have attracted great attention for presenting rich polymorphism and displaying superconductor or ferroelectric properties. In the present work, structural and vibrational properties of RbBi1/3W8/3O9 (RBW) crystal (VBHT type) were investigated by high‐pressure Raman scattering experiments. The results suggest the existence of a reversible pressure‐induced structural phase transition at about 4 GPa. This transformation is most likely related to rotations of octahedral units along the c‐axis with no abrupt changes of apical O W O bonds length. In order to get further understanding of RBW vibrational properties, we performed phonon calculations, by using classical lattice dynamics, in the related hexagonal structure of the K0.26WO6 system. These calculations revealed that most of vibrational properties of K0.26WO6 are governed by tubular ‘like’ vibrations of the hexagonal cavity, which resemble similar vibrations of tubular nanostructures. The pressure dependence of Raman modes is understood in terms of calculated phonon eigenvectors at ambient pressure. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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The structural parameters, mechanical, electronic and thermodynamic properties of TE-C36 under high pressure were calculated via the density functional theory in combination with the quasi-harmonic Debye model. The results show that the pressure has significant effects on the equilibrium structure parameters, mechanical, electronic and thermodynamic properties of TE-C36. The obtained ground state structural parameters are in good agreement with previous theoretical results. The mechanically and dynamically stable under pressure were confirmed by the calculated elastic constants and phonon dispersion spectra. The elastic constants, elastic modulus, B/G ratio, Poisson’s ratio and Vicker’s hardness were determined in the pressure range of 0–100?GPa. The elastic anisotropy of TE-C36 under pressure are also determined in detail. The electronic structure calculations reveal that TE-C36 remains a direct band gap semiconductor when the pressure changes from 0 to 100?GPa, and the band gap decreases with increasing pressure. Furthermore, the pressure and temperature dependence of thermal expansion coefficient, heat capacity and Debye temperature are predicted in a wide pressure (0–90?GPa) and temperature (0–2500?K) ranges. The obtained results are expected to provide helpful guidance for the future synthesis and application of TE-C36. 相似文献
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Brushite (CaHPO4·2H2O) has been extensively studied using X-ray1),2),3),4) and infrared techniques5),6),7),8). However, no Raman data have been reported in the literature for this phase. In this paper, we will present the nonpolarized and 相似文献