摘要:

AbstractThe Raman optical activity (ROA) spectra of some azo dyes binding to cyclodextrins have been measured. This appears to be the first successful attempt to measure the ROA induced in achiral molecules by intermolecular interaction with chiral molecules. There was no relationship between the ROA signals and the Raman shifts accompanying inclusion phenomenon. From comparison of the ROA spectra of methyl orange with α‐cyclodextrin and congo red with γ‐cyclodextrin, it seems that the ROA spectra reflect the difference in the positions of the SO3−groups in the guest mo

ISSN:0377-0486    

DOI:10.1002/jrs.1250180302

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractRaman spectra were obtained for aqueous solutions of MgCl2, Mg(NO3)2, MgSO4and Mg(ClO4)2in both liquid and glassy states. Spectral changes associated with the transition from the liquid to the glassy state were studied for the Raman OH stretching spectra, and the restricted translational Raman bands of the low‐frequency Raman spectra of the glassy solutions were characterized. It is shown that the spectral features and peak frequencies are greatly dependent on the chemical natures of the anion

ISSN:0377-0486    

DOI:10.1002/jrs.1250180303

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractTime‐resolved Raman spectroscopy (TRRS) is presented as a non‐invasive technique for measuring mixing/concentration profiles in a fully baffled disc turbine‐agitated

ISSN:0377-0486    

DOI:10.1002/jrs.1250180304

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe surface‐enhanced Raman (SER) spectra of aromatic amino acids (L‐phenylalanine,L‐tyrosine and tryptophan) and their glycyl dipeptides (glycyl‐L‐phenylalanine, glycyl‐L‐tyrosine and glycyl‐L‐tryptophan) adsorbed on Ag colloidal particles have been obtained. The surface‐enhanced and ordinary Raman spectra show satisfactory correlations. The most prominent features in the SER spectra of all compounds are the strongly enhanced peaks at about 930 and 1390 cm−1due to the CCOO−stretching and COO−symmetric stretching vibrational modes, respectively. This is interpreted as suggesting that the above compounds are adsorbed on the Ag surface through the carboxylate group. In the SER spectrum of glycyl‐L‐phenylalanine, the amide I and II bands are observed at about 1

ISSN:0377-0486    

DOI:10.1002/jrs.1250180305

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractRaman spectra of single crystals of CdMo6Cl14and CdMo6Br14were recorded with several directions of polarization. It is shown that the spectra must be interpreted from one [Mo6X8i]X6acluster, slightly distorted apart cubic ideal symmetry. All the vibrational modes are identified and their frequencies determined. This work is the first Raman study of ‘cube‐octahedral’ cluster Mo6X8in the solid

ISSN:0377-0486    

DOI:10.1002/jrs.1250180306

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe Raman spectra of solid odd‐numberedn‐alkanes were analysed in the frequency ranges corresponding to the LAM‐1 and the methyl rocking modes, in order to specify the nature and the quantity of thegaucheforms occurring in the high‐temperature phases. The evolution of the LAM‐1 frequency under different pressure and temperature conditions is discussed in connection with the interlamellar distances. In the high‐temperature phases, the relative quantity and the nature of thegaucheforms located at the ends and near the ends of the chains was estimated as functions of the chain length and of

ISSN:0377-0486    

DOI:10.1002/jrs.1250180307

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe Raman and infrared spectra of the superionic protonic conductor CsHSO4(CsDSO4) were investigated in the 18–450 K range. Polarized single crystal Raman and infrared reflection spectra were also studied at room temperature. An assignment of bands due to internal and external vibrations is given in terms of symmetry species and approximate type of motion. The spectroscopic results, in particular the behaviour of the Raman bands as a function of temperature, are used to discuss the crystalline structures of various phases, hydrogen bonding, the type and degree of structural disorder, phase transitions and conductivit

ISSN:0377-0486    

DOI:10.1002/jrs.1250180308

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractUltraviolet resonance Raman spectra of some guanine derivatives in aqueous solutions are reported, viz. guanosine,N1‐methylguanosine,N2‐methylguanosine andN2,N2‐dimethylguanosine. The effects of deuteriation were also investigated. The vibrational patterns of guanosine and the derivatives are complicated, since they involve contributions from both the pyrimidine and imidazole rings. However, the understanding of the spectral features is of special interest since some bands are highly sensitive to theBtoZconformational transition of alternating dG‐dC sequences containing DNA. From these UV resonance Raman spectra, assignments of the principal modes of vibration are proposed and discussed in relation to the results of normal coordinate calculations previously performed by other

ISSN:0377-0486    

DOI:10.1002/jrs.1250180309

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe Raman spectra of formaldehyde‐d0in water‐d0,2have been recorded. In such solutions formaldehyde is hydrated, thus giving rise to the presence of methylene‐d0glycol‐d0,2. With increasing concentration, methylene glycol polymerizes yielding soluble and insoluble polyoxymethylene hydrates. By varying the concentration of the solution, the observed Raman transitions could be assigned to vibrations corresponding to the monomer and/or the oligomer hydrates. The Raman spectra obtained for the partly deuteriated molecules permitted improved assignments for the OH bending vibrations and some HCH vib

ISSN:0377-0486    

DOI:10.1002/jrs.1250180310

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe structure of 2‐(2‐pyridylazo)‐5‐diethylaminophenol (PADAP) and its complex at various pH values was studied by resonance Raman spectroscopy. The spectral features are sensitive to the pH and the solvent, which can be explained in terms of azo–hydrazone tautomers. Two types of quinonoid structures are found under neutral conditions: a hydrazone structure in chloroform solution and a pyridone‐like structure with an NH bond in the pyridine ring in aqueous solution. The quinoid structure is found at both pH 0.1 and 2.3. The relationship between the structure and the absorption spectrum under neutral conditions is discussed on the basis of CNDO/2

ISSN:0377-0486    

DOI:10.1002/jrs.1250180311

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY