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1.
Abstract The compounds of beryllium - Be(IO3)2.4H2O, its deuterated analogue and Be(IO3)2 were studied by IR-spectroscopy over the range of 200 to 4000 cm?1. 相似文献
2.
J. Hanuza M. Maczka J. Lorenc A. A. Kaminskii P. Becker L. Bohatý 《Journal of Raman spectroscopy : JRS》2008,39(3):409-414
Polarized Raman and IR spectra of a PbB4O7 single crystal were measured. The obtained spectra are discussed within the factor group approach for the orthorhombic P21nm(C2v7) space group with Z = 2 assuming that the crystal structure is built up of the (B4O7)∞2− framework and Pb2+ ions. It has been shown that vibrations of borate and Pb2+ units are observed above 240 and below 160 cm−1, respectively. The results obtained for the spontaneous Raman scattering have also been used in the discussion of the stimulated Raman spectra of the material studied—a new Raman‐laser crystal. The obtained results revealed that mainly translational motions of Pb2+ ions participate efficiently in the SRS effect. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
3.
A study is carried out by FT-IR spectroscopy of the carbonate species formed upon interaction of CO2 with alumina and vanadia-alumina catalysts doped with sodium. It is found that the presence of sodium enhances the ability of the catalyst surface to adsorb CO2, yielding to carbonate formation. The species formed changes in the presence of vanadium, shifting the νCOO stretching bands towards higher wavenumbers than those recorded in Na-Al2O3 systems. 相似文献
4.
Low-temperature experiments of Raman scattering and heat capacity have been performed in a B2O3 glass, pressure quenched from 1200 °C in order to obtain the density as largest as possible (ρ = 2373 kg/m3). When compared to those of compacted B2O3 glasses having smaller density, the Raman spectrum of this glass exhibits a strong decrease of the intensities of the Boson peak and the band at 808 cm?1, both the features being determined by the decrease of the boroxol ring population. Moreover, the Boson peak exhibits a large shift to 68 cm?1 (from 26 cm?1 observed in normal vitreous B2O3). The high atomic packing of the glassy network also leads to a marked decrease of the excess heat capacity over the Debye T3-behaviour characterizing the crystal. The density g(ν) of low-frequency vibrational states has been assessed by using the low-frequency Raman intensity to determine the temperature dependence of the low-temperature heat capacity. The observations performed over a wide range of glass densities are compared to the predictions of theoretical models and computer simulations explaining the nature of the Boson peak. Consistency with the results of a simulation study concerning the vibrations of jammed particles leads to evaluate a nanometre length scale which suggests the existence of poorly packed domains formed from several connected boroxols. These soft regions are believed to be the main source of low-frequency optic-like vibrations giving rise to the Boson peak. 相似文献
5.
C. Yohannan Panicker Hema Tresa Varghese L. Ushakumary 《Journal of Raman spectroscopy : JRS》2009,40(12):2023-2030
The IR and Raman spectra of ethyl salicylate were recorded and analyzed. The surface enhanced Raman scattering (SERS) spectrum was recorded in a silver colloid. The vibrational wavenumbers of the compound have been computed using the Hartree‐Fock/6‐31G* basis. The direction of charge transfer contribution to SERS has been discussed from the frontier orbital theory. The presence of methyl modes in the SERS spectrum indicates the nearness of the methyl group to the metal surface and the presence of ring vibrations and out‐of‐plane ring modes in the SERS spectrum suggests a flat orientation of the molecule on the silver surface. The first hyperpolarizability is calculated and the calculated molecular geometry has been compared with the reported similar structures. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
6.
N. D. Strekal’ I. G. Motevich J. W. Nowicky S. A. Maskevich 《Journal of Applied Spectroscopy》2007,74(1):31-37
We present the IR absorption and surface-enhanced Raman scattering (SERS) spectra of the isoquinoline alkaloid berberine adsorbed
on a silver hydrosol and on the surface of a silver electrode for different potentials. Based on quantum chemical calculations,
for the first time we have assigned the vibrations in the berberine molecule according to vibrational mode. The effect of
the potential of the silver electrode on the geometry of sorption of the molecule on the surface is considered, assuming a
short-range mechanism for enhancement of Raman scattering.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 31–36, January–February, 2007. 相似文献
7.
We have used valence optical theory to carry out calculation and analysis of in-plane vibrations and intensities of IR spectra
for isolated 5-fluorouracil and 5-bromouracil molecules. We give a complete interpretation of the corresponding bands in the
absorption spectra. We have carried out a quantum mechanical calculations of the relative intensities in the resonant Raman
spectra of 5-fluorouracil and 5-chlorouracil. The calculated spectra for the molecular models obtained agree quantitatively
with the experimental spectra, and reproduce the observed characteristic spectral differences in the series of molecules:
uracil, 5-fluorouracil, 5-chlorouracil, and 5-bromouracil. The models obtained for the molecules can be used for calculation
and analysis of the spectra of other halosubstituted nucleic acid bases.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 437–442, July–August, 2006. 相似文献
8.
We have used IR spectroscopy to study the structure of tellurium germanate glasses synthesized in the system TeO2-GeO2-B2O3-PbO. The structure of the glasses consists of [BO3], [BO4], [GeO4], [GeO6], [TeO3], and [PbO6] groups. Changes in the coordination of boron and germanium ions occur when the PbO and GeO2 contents in the glasses increase. The glasses are attractive for designing optical and laser devices.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 78–81, January–February, 2007. 相似文献
9.
10.
Raman spectra of strontium borate binary glasses in the systemxSrO.(1-x)B2O3 forx=0.20, 0.25, 0.30, 0.35, 0.40, and 0.50 and ternary glasses in the system (SrCl2)
y
.[xSrO.(1−y−x)B2O3]1−y
fory=0.10, 0.20, 0.30 and 0.40 andx=0.20 and 0.35, are reported. Raman spectra of the glasses show experimental evidence of glass network modifying nature of
SrO in borate matrix. SrO causes a change of boron atom coordination number from 3 to 4 resulting in the complex structural
groupings comprising of BO4 and BO3 units. Strontium cations are not easily accommodated in the glass structure and tend to break up the network at high concentration
(x) of SrO, causing non-bridging oxygens. The effect of temperature variation of binary glasses has also been studied. The introduction
of SrCl2 to the binary stronium borate glass causes a large change in intensity of low frequency Raman scattering whereas there is
no change in the vibrational dynamics in the high frequency region. The temperature reduced Raman spectra represents true
vibrational density of states. Martin-Brenig model developed for the low frequency region has been discussed to obtain the
structural correlation range in the glass. 相似文献
11.
氨团簇(NH_3)_n(n=2~8)红外振动光谱的密度泛函理论研究 总被引:1,自引:0,他引:1
在密度泛函理论的基础上,利用B3LYP/6-31G(d)的方法计算得到了氨团簇(NH3)n(n=2~8)的最稳定构型,并对它们的红外振动光谱进行了理论计算和研究.结果表明氨团簇(NH3)n(n=2~8)的红外振动光谱按团簇分子的振动类型分主要分布在Ⅰ(0~1000 cm-1)、Ⅱ(1000~1500 cm-1)、Ⅲ(1500~3000cm-1)和Ⅳ(3000~4000 cm-1)四个区域;除n=2外,最强峰都出现在Ⅳ区域,并且随着团簇尺寸的增大,最强峰的强度有所增加,位置也出现明显的红移. 相似文献
12.
本工作系统地测量和分析了Li_O-(LiCl)_2-B_2O_3-Al_2O_3系玻璃的红外光谱,据此研究了玻璃中硼的配位数和硼酸盐结构基团随组成的变化以及Al~(3+)和Cl~-离子在结构中所起的作用,并对光谱中某些吸收峰机理作了定性探讨。 相似文献
13.
14.
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
15.
Abstract In order to aid assignment of Co-C bond stretching vibrational frequency of CH3Co(DH)2H2O (DH=dimethylgIyoximato monanion) in IR and Raman spectra, its isotopic substitution CD3Co(DH)2H2O has been synthesized and normal coordinate analyses on the two complex have been made. The bands were assigned in terms of potential energy distribution. The results provide definitive band assignment of the Co-C bond and Co-N bond stretching modes which are coupling at 511 cm?1. 相似文献
16.
利用密度泛函理论(DFT)中的B3LYP方法,在6-31G(d)基组水平上对1,8,15,22-四(3-戊氧基)自由酞菁的分子结构、分子轨道、原子电荷分布和红外光谱进行了研究。对酞菁骨架结构计算的键长 和晶体结构相差最大仅0.002 nm,最小的不足0.000 3 nm,表明了计算的酞菁骨架结构与晶体数据很吻合;对实验红外光谱图上的峰和模拟的峰的波数进行对应线性拟合,得出拟合直线的斜率为1.039, 截距为58 cm-1,说明计算的红外光谱和实验测得的对应得非常好。上述结果验证了所选取的理论方法和基组的可靠性。通过与未取代自由酞菁结构和性质的比较,发现烷氧基取代后的酞菁 分子中原子电荷仍然主要分布在酞菁环的内部,烷氧基的氧原子也带有较多负电荷。但是α-位烷氧基取代对整个酞菁分子结构和性质都产生很大的影响,烷氧基取代升高了HOMO和LUMO的能量,降低了 HOMO-LUMO能级,从而降低了其稳定性。借助正则坐标分析,对红外光谱中的重要吸收峰进行了详细的指认。 相似文献
17.
Raman and IR spectra of Bi2W2O9, the m = 2 member of the cation‐deficient Aurivillius phase, have been measured. The obtained spectra are discussed using the factor group approach for the orthorhombic Pna21(C2v9) space group. The results are compared with those obtained for Bi2WO6 and some m = 2 members of Aurivillius family of bismuth layered ferroelectrics. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
18.
C. Yohannan Panicker Hema Tresa Varghese K.R. Ambujakshan Samuel Mathew Subarna Ganguli Ashis Kumar Nanda Christian Van Alsenoy 《Journal of Raman spectroscopy : JRS》2009,40(9):1262-1273
Fourier transform infrared (FT‐IR) and Fourier transform (FT) Raman spectra of 3‐{[(2‐hydroxyphenyl)methylene]amino}‐2‐phenylquinazolin‐4(3H)‐one were recorded and analyzed. The vibrational wavenumbers of the title compound were computed using HF/6‐31G* and 6‐311G* basis sets and compared with experimental data. The assignments of the normal modes are done by potential energy distribution (PED)calculations. The prepared compound was identified by nuclear magnetic resonance (NMR) and mass spectra. Optimized geometrical parameters of the title compound are in agreement with reported structures. Shortening of CN bond lengths reveal the effect of resonance. The simultaneous IR and Raman activations of the CO stretching mode shows a charge transfer interaction through a π‐conjugated path. The first hyperpolarizability, infrared intensities and Raman activities are reported. The phenyl C C stretching modes are equally active as strong bands in both IR and Raman spectra, which are responsible for hyperpolarizability enhancement leading to nonlinear optical activity. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
19.
M. Maczka A. Pietraszko J. Hanuza A. Majchrowski 《Journal of Raman spectroscopy : JRS》2010,41(10):1297-1301
Single crystals of optical nonlinear borate, Bi0.21La0.91Sc2.88(BO3)4, were grown and polarized Raman and IR spectra were recorded for this material at room temperature. The spectra have been discussed on the factor group approach for the trigonal R32 (D37) space group with Z = 3. The assignment of the observed bands to the respective internal and lattice modes is proposed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
20.
Eu3+掺杂Bi2O3-TeO2-B2O3-ZnO玻璃光谱性质 总被引:4,自引:1,他引:4
测量了Eu3+(1 mol%)掺杂(60-χ)Bi2O3-χ TeO2-30B2O3-10ZnO(χ=5,10,20,30,摩尔百分比)玻璃的吸收光谱、发射光谱、激发光谱以及声子边带谱.根据稀土离子Eu3+光学跃起矩阵元的特点,从发射光谱获得了Eu3+光学跃起的J-O参数Ω2与Ω4.结果显示,强度参量Ω2随着Bi2O3量的增加与TeO2量的减少而减小,表明材料的对称性提高, Eu-O键强减弱,共价性减弱.随着Bi2O3量的增加,电-声子偶合减弱,材料的热稳定性大幅度提高. 相似文献