摘要:

AbstractThe anisotropic Raman spectra of liquid 1,4‐dioxane have been recorded at several temperatures and at different concentrations of aqueous and carbon tetrachloride solutions. The rotational dynamics of the 1,4‐dioxane molecules under these conditions is discussed in terms of appropriate correlation functions, reorientational relaxation times and second‐order rotational spectral mo

ISSN:0377-0486    

DOI:10.1002/jrs.1250180702

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe Raman and IR spectra of 1,4‐dichlorobut‐2‐yne (DCB) as a liquid at various temperatures and as an amorphous and as metastable and stable crystalline solids at low temperatures have been recorded in the 4000–20 cm−1range. Additional IR and Raman spectra of a high‐pressure crystalline phase were obtained atca17 kbar pressure.The broad unsymmetrical bands of DCB in the liquid and in the amorphous solid below 500 cm−1suggest nearly free rotation in these phases at all of the temperatures investigated. Belowca190 K a crystal containing theantiand above 190 K a crystal containing thegaucheconformer of DCB were formed; the latter crystal is believed to be thermodynamically more stable at all temperatures. Only one high‐pressure crystal with molecules in theanticonformation was formed at room temperature. A phase transition reported at 232 K in the liquid, involving a conversion to ananticonformer, was not detected.Complete vibrational assignments for bothantiandgaucheconformers are presented, supported by force consta

ISSN:0377-0486    

DOI:10.1002/jrs.1250180703

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractMyelin membrane and its proteolipid protein (PLP) have been examined by infrared and Raman spectroscopy to provide information about the secondary structure of proteins and conformation of lipid chains. Splitting of the amide I modes in the vibrational spectra and locations of amide A, I, II, III and V bands indicate that the polypeptide arrangement in both membrane systems is mainly helical. The β‐form is also present, its amount being higher in PLP. Raman spectra in the CC and CH stretching regions show significant differences concerning intra‐ and inter‐chain lipid order, which is grea

ISSN:0377-0486    

DOI:10.1002/jrs.1250180704

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractFermi resonances are analysed in the literature either by degenerate first‐order perturbation theory or by the coupled oscillator model of Schwartz and Wang. Here the perturbation treatment is generalized, taking into account the coupling not only between a fundamental and an overtone, but also with other eigenstates, required by a proper treatment of the Bose character of vibrations. The resulting expressions for the frequency shifts differ from those of both other models. Numerical differences from the first‐order perturbation treatment are small in most cases. However, the results can be used to relate the empirical interaction constant of the coupled oscillator model to an actual anharmonicity const

ISSN:0377-0486    

DOI:10.1002/jrs.1250180705

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractOn the basis of bond polarizability model, expressions for second derivatives of the polarizability tensor with respect to the normal coordinates of planar and pyramidal AB3molecules are presented. Using the results obtained, the relationship between the first and the second derivatives of the mean polarizability is found.

ISSN:0377-0486    

DOI:10.1002/jrs.1250180706

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe Raman and infrared spectra of NiCl2·6H2O, NiCl2·6D2O, CoCl2·6H2O, CoCl2·6D2O and CoBr2·6H2O single crystals have been measured in the range 3600–30 cm−1(Raman) and 3800–400 cm−1(IR). The water internal modes have been best assigned for NiCl2·6H2O, including Fermi resonance effects. The corresponding Raman intensities have been interpreted in terms of the free molecule Raman tensors. Among the lattice vibrations, the metal halide and metal‐water stretchings, and also the librations of the MX2·4H2O octahedra, have been identif

ISSN:0377-0486    

DOI:10.1002/jrs.1250180707

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractA Raman band at 710 cm−1has been used for the study of the NO3−ion reorientation and of the phase transitions in [Ni(NH3)6](NO3)2. The strong temperature dependence of the width of this band in phase I is evidence for the NO3−reorientation in this phase. The reorientations stops in phase II. The same band was used for studying the phase II/phase III transition. The large thermal hysteresis of this transition has been conf

ISSN:0377-0486    

DOI:10.1002/jrs.1250180708

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractA comparative Raman band shape study of the reorientation of monosubstituted benzene molecules (C6H5X, X = CH3, CH2Cl, CHCl2, CCl3and CCCH3) in the liquid phase has been performed. Reorientational correlation functions appear to be less sensitive to molecular reorientation about the major axis (Zaxis) than to rotation of the axis itself, approaching a symmetric top case. Molecular motion anisotropy is found to increase in the order C6H5CH3

ISSN:0377-0486    

DOI:10.1002/jrs.1250180709

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractLes structures rotationnelles des bandes Raman ν6et ν8de l'éthylène‐d0et de l'éthylène‐d4à l'état gazeux ont été enregistrées. Le contour de chaque bande perturbée ν8a été analysé en simulant les bandes du rotateur asymétrique, ce qui a permis de mettre en évidence les effects d'une interaction de Coriolis de type a. La constante de Coriolis, ζ 6a,8 a été d

ISSN:0377-0486    

DOI:10.1002/jrs.1250180710

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractLes spectres de rotation pure de C2H4et de C2D4ont été enregistrés. La reproduction des contours expérimentaux par des spectres simulés permet d'évaluer le rapportRégal à 0.21 pour C2H4et 0.23 pour C2D4. Les valeurs des polarisabilités optiques principales, et les relations de αzz, αyy, αxxetRen fonction des polarisabilités de liaison de l'éthylène permettent de montrer l'évolution croissante deRavec

ISSN:0377-0486    

DOI:10.1002/jrs.1250180711

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY