摘要:

AbstractDepending on the nature of the electronic absorption spectrum, that is, whether there are resolved vibronic transitions or broad and structureless bands, the scattering time associated with the Raman process can be long (10−8–10−12s) or short (<10−12s). In the first case the resonance Raman spectrum is characterized by a strong and non‐systematic dependence of first and higher order processes on the exciting wavelenghth; In the latter case the resonance Raman spectrum exhibits a strong, but systematic, frequency dependence of the intensities, which also show a regular decrease with the order of the process. These effects have been interpreted in terms of the Fourier transform of the correlator function which describes the time dependence of the secondary emission, evaluated for intermediate and long times and for the short time limit, respectively, Calculations for the gaseous I2molecule using a simplified model Hamiltonian are reported and compared with the experime

ISSN:0377-0486    

DOI:10.1002/jrs.1250150302

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractBinary mixtures of all‐trans‐N‐retinylidene‐n‐butylamine (NRB) in hexafluoroisopropanol (HFIP) were irradiated by various laser lines. The laser lines served both as sources of photoconversion and for Raman excitation. The photoproducts were studied by clectronic and resonacnce Raman Spectroscopy. The high specificity of resonance Raman spectroscopy was used to characterize different photoproducts at concentrations of the order uf 10−5m, present simultaneously in the same mixture. The results show that a partial break in conjugation occurs during the phototransformation. The electronic spectra of the photoproducts were compared with the electronic spectra of modified chromophores

ISSN:0377-0486    

DOI:10.1002/jrs.1250150303

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe polarized and depolarized Raman spectra of the ν2(CH2bend) and ν3(CBr stretch) vibrations in dibromomethane have been studied as a function of temperature throughout the liquid range. Reorientational correlation times derived from the two modes were simllar in both magnitude and dependence on temperature. This result, together with other structural data, suggests that the rotational dynamics of this molecule in the liquid phase are quasi symmetric‐top in character. Vibrational dephasing times calculated from the two lineshapes were also of the same magnitude. However, modulation times determined via the Kubo lineshpae formalism varied markedly between the vibrations. This provides evidence that vibrational dephasing of the bending and stretching modes are influenced by different intermolecular forces in the l

ISSN:0377-0486    

DOI:10.1002/jrs.1250150304

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractQuantitative measurements of chromium oxide film thicknesses on pure chromium have been made using Raman scattering. The results are compared with those from argon ion erosion. Possible developments of the technique to the chemical mapping of corrosion film using Raman scuttering are discussed.

ISSN:0377-0486    

DOI:10.1002/jrs.1250150305

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractSurface‐enhanced Raman spectra of 2,2′‐bipyridine, Ru(bpy)(py)4(CIO4)2, Ru(py)6(BF4)2and Ru(bpy)‐(PVP)(CIO4)2at the surface of a copper electrode are presented [bpy = 2,2′‐bipyridine; py=pyridine; and PVP =poly(4‐vinylpyridine)]. The dependence of the spectra on potential is demonstrated through presentation of complete spectra at applied potentials from −0.2 to −1 V, as well as in plots of SER intensityvselectrode potential. The effect of excitation wavelength on the spectra is discussed. Significant differences between the potential dependences of these compounds at copper and silver electrode surfaces are shown. SER spectra from the surface‐enhanced resonance Raman active ruthenium complexes could be obtained only with an excitation wavelength l

ISSN:0377-0486    

DOI:10.1002/jrs.1250150306

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe Raman spectra of KOX (X  H or D) at 77 K and room temperature are reported. The observed frequencies are assigned on the basis of a normal coordinate analysis by use of the valence force field. The KO stretching force constants are consistent with those expected from bond distances or related compounds. Dispersion relations are derived and some bands are assigned to a combination band at critical poi

ISSN:0377-0486    

DOI:10.1002/jrs.1250150307

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractA method utilizing divided KBr discs has been developed for estimating the relative intensities of the resonance Raman bands of different samples in the solid state. The relationship between the band intensity and the sample concentration in the disc is described on the basis of the Kubelka‐Munk theory of diffuse reflection. The utility of the method was checked by using crystalline methyl orange and potassium sulphate as the sample and reference materials, respectively. By comparing the measured and calculated intensities, the Raman scattering coefficient of the NN stretching band of methyl orange at 1420 cm−1was estimated to be 440±90 times as large as that of the 984 cm−1band of potassium

ISSN:0377-0486    

DOI:10.1002/jrs.1250150308

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe resonance Raman spectra of specifically deuteriated divalentd6metal complexes are reported. These include the iron(II) and ruthenium(II) perdeuteriated complexes and the Ru(bpy‐3,3′‐d2)32+and Ru(bpy‐6,6′‐d2)32+complex ions. The syntheses of the deuteriated ligands are reported and the frequency shifts observed on deuteriation are correlated with the natural abundance iron(II), ruthenium(II) and osmium(II

ISSN:0377-0486    

DOI:10.1002/jrs.1250150309

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe infrared spectra (4000–400 cm−1) of gaseous, liquid and solid (cyanomethyl) cyclopropane have been recorded for the first time. Additionally, the Raman spectra (3500–50 cm−1) of condensed phases of this substance have also been obtained. ‘Extra’ Q branches have been observed in the gas‐phase infrared spectrum, and six liquid‐phase Raman doublets (two of which are also seen in the infrared spectrum of the liquid) have also been observed, wherein one member of each doublet vanishes once the polycrystalline solid state spectrum is obtained. These data have been interpreted in terms of a two conformer (gauche/cis) fluid‐phase equilibrium for (cyanomethyl)cyclopropane, with only thegaucheconformer remaining in the solid phase. The temperature behavior of the 774/756 and 835/855 cm−1liquid‐phase Raman doublets yields an enthalpy difference between conformers of 0.72±0.10 kcal mol−1, with thegaucheconformer the more stable. This ΔHvalue implies a room‐temperature conformational equilibrium for (cyanomethyl)cyclopropane composed of 87%gaucheand 13%cisrotamers in the liquid phase. In addition, a vibrational assignment for the 33 normal modes of (cyanomethyl)cyclopropane has been proposed, and it is in excellent agreement with the previously published vibrational assignments for thre

ISSN:0377-0486    

DOI:10.1002/jrs.1250150310

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractLes interactions isobutylamine‐eau ont été étudiées par spectroscopie de vibration infrarouge et Raman. L'étude préliminaire de l'isobutylamine pure montre l'existence, dans l'état liquide, de deux isomères de rotation, un seul conformère étant favorisé par cristallisation. Dans l'état solide les fréquences de vibrations sont caractéristiques de l'existence de liaisons hydrogène due à un enchaǐnement (RNH2)xdans lequel l'environnement de l'atome d'azote est tétraèdrique. L'analyse des spectres infrarouge et Raman du complexe équimoléculaire isobutylamine‐eau montre la formation de chaǐnes dans lesquelles la molécule d'eau casse la liaison NH…︁N pour former une liaison NH…︁O. Les fréquences de vibration sont en accord avec un environment tétraèrdique de l'atome d'oxygène analogue à celui observé pour l'atome d'oxygène dans le glace II. Les spectres de l'homologue deutérié sont beaucoup plus complexes du fait de l'apparition d'un échange hydrogè

ISSN:0377-0486    

DOI:10.1002/jrs.1250150311

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY