摘要:

AbstractBand intensities in the polarized Raman spectra have been measured for the CO2−stretching, the CH2stretching and the CH2bending modes of α‐glycine crystal and the CO2−stretching and the CH3symmetric deformation modes ofL‐ andDL‐alanine crystals. Variations in the relative band intensities on the change of the scattering geometry have been elucidated by applying the oriented gas model to the local groups, –CH2, –CH3and –CO2−, of these amino acid crystals. The calculated values of the components of the derived polarizability tensors are consistent with the geometry of the groups. The depolarization ratios estimated from the calculated anisotropy of the polarizability tensors have been compared with those observed for

ISSN:0377-0486    

DOI:10.1002/jrs.1250090302

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractBelow 162K, carbon disulphide crystallizes in the space groupD2h18with two molecules in the primitive cell. The internal modesv1,v2andv3of the isolated CS2molecule are split due to static and correlation field splittings. Andersonet al. have extensively studied the Raman and infrared spectra of CS2at 79 K and 18 K and have analysed the internal and external modes with a lattice dynamical calculation of theq= 0 phonons. However, their spectra reveal the presence of extensive second order features accompanying thev1,v2,v3and 2v1bands. The present investigation attempts an interpretation of these second order Raman spectra employing Born's theory and the lattice dynamical calculation of phonons at all allowedqpoints in the Brillouin zone employing the rigid molecule approximation.

ISSN:0377-0486    

DOI:10.1002/jrs.1250090303

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe Raman spectra of three deuferated poly(methylmethacrylate) derivatives, —(CH2C(CD3)COOCD3)n, —(CD2C(CH3)COOCD3)nand —(CD2C(CD3)COOCH3)n, are measured and the assignment of the CH stretching and bending vibrations of the methylene, α‐methyl and ester methyl groups of PM

ISSN:0377-0486    

DOI:10.1002/jrs.1250090304

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe Raman spectra of bromine and iodine adsorbed on 5A and 13X zeolites from carbon tetrachloride solutions presented bands that were assigned to chemical and physical adsorption. Using a rotating cell and an oscillating optical system it was possible, choosing a convenient laser power, to aid the bands due to chemisorption.

ISSN:0377-0486    

DOI:10.1002/jrs.1250090305

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe polarized Raman spectra of monoclinic CBr4are interpreted in terms of pseudo‐cubic site symmetry42m. The large polarizability of Br atoms is responsible for the high intensity of the off‐diagonal terms of total symmetric tensors. Dipole–dipole coupling gives, for thev3mode, a quite different behaviour from that of the other internal

ISSN:0377-0486    

DOI:10.1002/jrs.1250090306

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe rotational‐vibrational Raman Spectrum of thev2band of H14N3has been measured. The results of the analysis of the observed wavenumbers arev0= 2140.308(4) cm−1, ΔB= −0.00312(1) cm−1and ΔDj= −7(5)×10−9cm−1. TheQ‐branches of the hot band transitionsv5→v2+v5andv6→v2+v6have been determined t

ISSN:0377-0486    

DOI:10.1002/jrs.1250090307

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractWe have designed and assembled a sensitive vidicon Raman spectrometer which is shown to be well suited for the studies of heme proteins in both Soret (near‐ultraviolet) andQ(visible) band regions. This system, employing a dry ice‐cooled silicon intensified target (SIT) detector and an additive dispersion double monochromator (two 600 g mm−1gratings blazed at 400 nm), has excellent stray light rejection and optimum bandpass and resolution (5–12 cm−1) for biological applications. It is demonstrated that a 600 cm−1wide section of the low frequency Raman spectrum of ferrocytochromecexcited at 413.1 nm (70 mW) can be obtained in 30 ms, which is ˜ 2×104times faster than that required by the conventional scanning techniques. Our multichannel Raman system has an enhanced detection capability which enables us to identify at least 41 weak Raman lines below 850 cm−1in the spectrum of ferrocytochromec. Using the SIT detection system, the Raman excitation profile of a depolarized line at 750 cm−1in Fe(II) cytochromechas been constructed and compared with that reported for Ni etioporphyrin. Instead of strong 0–0 Raman intensity, the cytochromecprofile exhibits weaker 0–0 intensity, indicative of the absence of the Jahn‐Teller effect. It is further demonstrated that the Soret‐excited Raman spectrum of oxyhemoglobin can be readily obtained

ISSN:0377-0486    

DOI:10.1002/jrs.1250090308

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractResearch on the Raman spectrum shows that the features of the different phases of which semi‐crystalline polyethylene is composed can be obtained through bending vibrations of δ (CH

ISSN:0377-0486    

DOI:10.1002/jrs.1250090309

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractResearch on the polarization of bending vibrations of CH2makes it possible to deduce the orientation of the different phases of polyethylene. When the sample is stretched, the orthorhombic monocrystalline phase becomes parallel to the stretching axis but the other two phases take a more or less perpendicular direction.

ISSN:0377-0486    

DOI:10.1002/jrs.1250090310

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe low frequency Raman spectra of CF3OF (gas, liquid), CF3OCI (liquid), CF3OOH (gas, liquid), CF3OOD (liquid), CF3OOF (gas, liquid) and CF3OOCI (liquid) have been recorded below 300 cm−1. The spectra have been assigned and the CF3torsional modes were observed for all of these compounds in the liquid state. The assigned frequencies for the liquids and the calculated barriers for the vapor state are: CF3OF, ντ= 144 cm−1,V3= 4.64 kcal mol−1; CF3OCI, ντ= 122 cm−1,V3= 4.6 kcal mol−1; CF3OOH, ντ= 155 cm−1,V3= 6.0 kcal mol−1; CF3OOF, ντ= 78 cm−1,V3= 2.9 kcal mol−1; and CF3OOCI, ντ= 80 cm−1,V3= 3.7 kcal mol−1. The assignments are discussed and the barriers are compared to the corresponding quant

ISSN:0377-0486    

DOI:10.1002/jrs.1250090311

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY