The interpretation of the infra-red and Raman spectra of the n -paraffins

1954 ◽  
Vol 247 (922) ◽  
pp. 35-58 ◽  
Keyword(s):  
Raman Spectra ◽  
Principal Series ◽  
Experimental Results ◽  
Absorption Bands ◽  
Infra Red ◽  
Complete Set ◽  
Stretching Vibrations

Infra-red spectra of a series of crystalline n -paraffins containing an odd number of carbon atoms have been obtained. The spectrum of oriented crystals of n -nonadecane has also been examined. These new experimental results have been combined with the earlier data on the crystalline n -paraffins containing an even number of carbon atoms, and many series of absorption bands have been identified in the complete set of spectra. These regularities, as well as those present in the Raman spectra, have been interpreted in terms of CH 2 , CH 3 , and C—C stretching vibrations. Very regular distributions of frequencies have been found between 720 and 1030 cm -1 and between 1200 and ca. 1370 cm -1 , which are assigned to CH 2 rocking and wagging vibrations, respectively. The majority of the absorption bands between 1150 and 880 cm -1 can be attributed to C—C stretching or CH 3 rocking modes, and assignments are suggested for the principal series observed in this region.

The infra-red absorption bands associated with the COOH and COOD groups in dimeric carboxylic acids. I. The region from 1500 to 500 cm -1

1953 ◽  
Vol 216 (1125) ◽  
pp. 247-266 ◽  
Keyword(s):  
Carboxylic Acids ◽  
Raman Spectra ◽  
Crystalline Solid ◽  
Cooh Group ◽  
Absorption Bands ◽  
Solid States ◽  
Infra Red ◽  
Out Of Plane ◽  
Stretching Vibrations ◽  
Skeletal Deformation

The infra-red spectra of a considerable number of carboxylic acids and their COOD derivatives have been investigated between 1500 and 500 cm -1, as dimeric units in the liquid or crystalline solid states. Under these conditions the COOH group is shown usually to give rise to strong absorption bands in the regions 1420 ±20, 1300 ± 15 and 935 ± 15 cm -1 . The first two of these are found to correspond to closely coupled OH deformation and C—O stretching vibrations occurring in the plane of the (COOH) 2 dimeric ring; the latter is caused by the out-of-plane OH deformation vibration. COOD groups have absorption bands in the ranges 1350 ±50, 1050 ± 10 and 675 ±25 cm -1 , which can be assigned respectively to the C—O stretching mode and the in-plane and out-of-plane OD deformation vibrations. Less constant absorption bands of the COOH group between 700 and 575 cm -1 are attributed to O—C = O skeletal deformation vibrations, and the corresponding bands are found at slightly lower frequencies in the spectra of the COOD derivatives. The results of the infra-red investigation are compared with the Raman spectra of such acids and with related infra-red and Raman frequencies of other molecules. Infra-red spectra of some equimolecuiar mixtures of acids with water have also been studied.

RAMAN SPECTRA OF THE H2SO4–SO3 AND D2SO4–SO3 SYSTEMS: EVIDENCE FOR THE OCCURRENCE OF POLYSULPHURIC ACIDS

1962 ◽  
Vol 40 (4) ◽  
pp. 658-674 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Sulphuric Acid ◽  
Raman Spectra ◽  
Ionic Species ◽  
The Self ◽  
Experimental Results ◽  
Similar Work ◽  
Stretching Vibrations ◽  
Sulphur Trioxide ◽  
High Concentrations

The Raman spectra of oleums, i.e. mixtures of sulphur trioxide and sulphuric acid, have been re-examined. Similar measurements on the sulphur trioxide – deuterosulphuric acid (D2SO4) system are also reported. The experimental results and conclusions of previous similar work on oleums are discussed. By comparison of the spectra of oleums with those of the polysulphuryl halides it is shown that the polysulphuric acids H2S2O7 and H2S3O10 are present in this system. The increase in the frequency of the SO2 stretching vibrations with increasing concentration of sulphur trioxide gives evidence for the existence of higher polysulphuric acids such as H2S4O13 at high concentrations of sulphur trioxide. In relatively concentrated oleum, sulphur trioxide monomer and trimer are also present. It is shown that the self-dissociation of liquid H2S2O7 gives mainly molecular H2S2O10 and H2SO4 and not ionic species. The conclusions reached from the interpretation of the Raman spectra of the D2SO4–SO3 system are similar to those arrived at for sulphuric acid oleums. The spectra of solutions of NaHSO4 in oleums were also examined, and are discussed.

Vibrational band intensities in substituted anilines

1957 ◽  
Vol 243 (1233) ◽  
pp. 143-153 ◽  
Keyword(s):  
Linear Relation ◽  
Vibrational Band ◽  
Vibration Band ◽  
Substituted Anilines ◽  
Absorption Bands ◽  
Bond Stretching ◽  
Infra Red ◽  
Analogous Data ◽  
Stretching Vibration ◽  
Stretching Vibrations

The infra-red absorption bands associated with the stretching vibrations of the NH 2 group in a series of meta - and para -substituted anilines have been examined. The effect of the sub­stituet groups upon the frequencies and intensities of the bands has been correlated with their Hammett σ factors. The widths of the bands have also been found to depend upon the position and nature of substituent. The linear relation between log (intensity) and σ suggested previously on the basis of other data has been found to hold in this case too. Measurements in several solvents have been compared, and surprising variations of band intensity have been found. Analogous data have been obtained for the N—H bond stretching vibration band in substituted N -methyl anilines. The effect of ortho substituents has also been examined in a few cases.

The raman spectra of some aromatic sulphonyl Halides

1953 ◽  
Vol 6 (2) ◽  
pp. 135 ◽  
Author(s):  
NS Ham ◽  
AN Hambly
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Raman Band ◽  
Absorption Bands ◽  
Strong Band ◽  
Liquid Benzene ◽  
Infra Red ◽  
Group A ◽  
Methyl Benzene ◽  
Sulphonyl Fluoride

The Raman spectra of benzene-, p-chlorobenzene-, p-bromobenzene-, p-methoxybenzene-, and o-, m-, and p-toluene sulphonyl chlorides and fluorides and methylbenzene sulphonate are recorded as well as the infra-red absorption bands of liquid benzene sulphonyl chloride and fluoride between 650 and 3100 cm.-l. A frequency c. 375 cm.-1 is characteristic of the S-Cl bond in sulphonyl chlorides and a strong band at c. 1210 cm.-1 is characteristic of the sulphonyl fluoride group. A Raman band at c. 1080 cm.-l in the chlorides and c. 1095 cm.-l in the fluorides appears to be associated with aromatic sulphonyl derivatives. There is such a band at 1094 cm.-1 in the Raman spectrum of methyl benzene sulphonate.

Vibrational spectra of aquadioxotetra; peroxodivanadates(V) M2[V2O2(O2)4(H2O)]·xH2O (M = N(CH3)4, Cs)

1990 ◽  
Vol 55 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Peter Schwendt ◽  
Milan Sýkora
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Infrared And Raman Spectra ◽  
Empirical Correlations ◽  
Normal Coordinate ◽  
Bond Lengths ◽  
Stretching Vibrations

The infrared and Raman spectra of M2[V2O2(O2)4(H2O)]·xH2O and M2[V2O2(O2)4(D2O)]·xD2O (M = N(CH3)4, Cs) were measured. In the region of the vanadium-oxygen stretching vibrations, the spectra were interpreted based on normal coordinate analysis, employing empirical correlations between the bond lengths and force constants.

The infra-red spectrum and molecular configuration of sodium deoxyribonucleate

1957 ◽  
Vol 239 (1219) ◽  
pp. 446-463 ◽  
Keyword(s):  
Relative Humidity ◽  
Vapour Phase ◽  
Molecular Configuration ◽  
Absorption Bands ◽  
Oriented Films ◽  
Infra Red ◽  
Modes Of Vibration ◽  
Water Measurement ◽  
Phosphate Groups ◽  
Polarized Radiation

The infra-red spectra of oriented films of sodium deoxyribonucleate have been investigated between 700 and 4000 cm -1 using polarized radiation and under varying degrees of relative humidity. Similar spectra have been obtained when the films have been deuterated by vapour-phase exchange with heavy water. It is found that the infra-red dichroism of nearly every band increases with the relative humidity. Many of the principal absorption bands can be assigned to separable modes of vibration in the bases, the phosphate groups or the absorbed water. Measurement of the dichroic ratios of certain of these bands indicates that at high relative humidity the bases must be nearly perpendicular to the orientation direction. The configuration deduced for the phosphate groups is unlike that proposed in the Crick-Watson model, but is in essential agreement with that recently proposed by Wilkins and his co-workers. Some observations are also reported on the corresponding spectra of sodium ribonucleate. Since no dichroism was observed, no conclusions can be drawn regarding the molecular configuration of this polymer.

Raman spectra of CN vibrations of acetonitrile in aqueous and other solutions. Experimental results andab initio calculations

2005 ◽  
Vol 36 (10) ◽  
pp. 932-937 ◽  
Author(s):  
F. H. Tukhvatullin ◽  
A. Jumabaev ◽  
G. Muradov ◽  
H. A. Hushvaktov ◽  
A. A. Absanov
Keyword(s):  
Raman Spectra ◽  
Experimental Results
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