摘要:

AbstractThe effect of cholesterol in equimolar concentrations on five different types of phospholipids in aqueous systems is reported. The phospholipids varied in chain length and chain unsaturation. This investigation confirms that the CH stretching region at 2700–3100 cm−1is sensitive to conformational changes in the hydrocarbon chains. Moreover, this region of the Raman spectrum shows that small changes in band intensities can be correlated with the effect of the cholesterol on aqueous lecithin system both above and below the chain transition temperature (Tc). The results indicate that cholesterol moderates the change in chain mobility in both directions of the transition liquid crystal⇌gel phase. This effect is larger in lecithins with saturated chains compared to unsaturated

ISSN:0377-0486    

DOI:10.1002/jrs.1250050102

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractThis paper describes a simple numerical method for the smoothing and differentiation of digitally collected Raman spectra. This is applied to a peak finding program suitable either for batch processing of data or real time application with a computer controlled spectrometer. A basis for the implementation of such programs is given, and their limitations are discussed.

ISSN:0377-0486    

DOI:10.1002/jrs.1250050103

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractThe infrared, far‐infrared, and Raman spectra of crystalline cyanoacetylene and its deutero, chloro, bromo, and iodo derivatives were found to be consistent with the known crystal structures of these compounds. However, no definite evidence could be obtained for the existence of a distinct low‐temperature crystalline modification of iodocyanoacetylene suggested earlier from X‐ray diffraction

ISSN:0377-0486    

DOI:10.1002/jrs.1250050104

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractThe pure rotational Raman spectrum of borazine (B3N3H6) vapor was photographed with a high resolution plane grating spectrograph. Two sets of rotational spectra, each consisting ofR‐ andS‐branches, are observed and are assigned to the molecules11B3N3H6and11B210BN3H6which are concurrently present in a sample containing boron in its natural isotopic abundance. Spectral features which are due to the other two isotopic variants of borazine (11B10B2N3H6and10B3N3H6) were not detected. From the observed rotational lines the following constants were determined. For the symmetric top molecule11B3N3H6, B = 0.175581 cm−1, DJ= 2.36 × 10−8cm−1while for the slightly asymmetric top molecule11B2BN3H6B =1/2(A + B) = 0.177565 cm−1and Dj= 4.39 × 10−8cm−1. Since an appreciable number of molecules are in excited vibrational states at room temperature the observed spectra are composites of pure rotational transitions in these excited vibrational states as well as the ground state. The above constants are therefore averages over the ground and excited vibrational states of these molecules. Since resolved spectral features due to11B10B2N3H6and10B3N3H6were not detected the above constants must also be viewed as averages over these isotopic variants.TheB‐value for11B3N3H6was calculated using the electron diffraction structures for two suggested models, havingC2andD3hsymmetry. These computedB‐values are in disagreement with the observed, spectroscopicB‐valu

ISSN:0377-0486    

DOI:10.1002/jrs.1250050105

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractData on the Raman spectra of natural α‐Glycine and15N‐substituted α‐Glycine are presented together with details of a computer calculation of the normal vibrations. Assignments are made and compared with previous assignments based on IR measu

ISSN:0377-0486    

DOI:10.1002/jrs.1250050106

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractThe vibrational assignments for the liquid phase of tricyclo(3.3.0.02,6)octane (TCO) are herein presented. Special emphasis was placed upon identification of polarized lines with respect to Fermiresonance interactions. The rigidity of the molecule is discussed.

ISSN:0377-0486    

DOI:10.1002/jrs.1250050107

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractA low‐temperature single‐crystal Raman study of mercury(I) nitrate dihydrate is reported, together with low‐temperature powder Raman and i.r. spectra of the nitrate and of mercury(I) bromate and sulphate. The spectra are given consistent interpretations in terms of factor group analysis. Of note is assignment of ν(HgO) in the 250–265 cm−1interval for coordinated bromate and sulphate; the demonstration that there is no correlation coupling for ν(HgHg) which consequently appears in the Raman spectra as a single band; and a mercurous ion rotatory mode r

ISSN:0377-0486    

DOI:10.1002/jrs.1250050108

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractUsing a simple model system, a discussion is given of vibronic coupling between two excited electronic states, |e〉 and |s〉, through a non‐totally symmetric vibration along a normal coordinateQ.It is shown that such a vibronic coupling causes, on the one hand, Raman scattering associated with the vibration alongQ, and on the other hand a flattened potential function or a double‐minimum potential function of the lower electronic excited state |e>alongQ.The stronger the coupling, the stronger the scattering; and, at the same time, the more severe the flattening (or the greater the separation between the two minima) in the potential function. As an example, theb1gvibration at 917 cm−1of pyrazine has been fitted with

ISSN:0377-0486    

DOI:10.1002/jrs.1250050109

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractThe vibrational Raman spectra of some Gramicidin antibiotics and Gramicidin/lipid/water systems are reported. From comparison of these spectra some information can be obtained regarding changes in the tertiary structure of the antibiotic and changes in the hydrocarbon chain conformation within the bilayer on formation of the antibiotic/lipic/water complex.

ISSN:0377-0486    

DOI:10.1002/jrs.1250050110

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY

摘要:

AbstractThe polarized signals from the methyl group stretching coordinate of toluene‐d5have been analyzed by the time correlation technique. Based upon the polarized signal correlation function of the 2922 cm−1signal and the presence of Fermi resonance in the molecule, mechanistic interpretations of a vibrational internal conversion process are offe

ISSN:0377-0486    

DOI:10.1002/jrs.1250050111

出版商:John Wiley&Sons, Ltd.    

年代:1976

数据来源: WILEY