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.

Studies of the Jahn - Teller effect IV. The vibrational spectra of spin-degenerate molecules

1962 ◽  
Vol 255 (1050) ◽  
pp. 31-53 ◽  
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Physical Theory ◽  
Vibronic Coupling ◽  
Infra Red ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Active Vibration ◽  
Degenerate States

The physical theory necessary for interpreting the vibrational spectra of spin-degenerate molecules is developed in this paper. Particular attention is paid to those molecules whose behaviour is expected to be markedly different from that of both orbitally non-degenerate molecules and those with purely spatial degeneracy. These include certain Kramers degenerate molecules, whose Raman spectra are expected to contain reverse-polarized contributions, and also tetrahedral and octahedral molecules in fourfold degenerate states. The case of a fourfold degenerate octahedral molecule is investigated in the limits of strong vibronic coupling by one of the Jahn—Teller active vibrations (e g and t 2g ). It turns out that the forbidden t 2u vibration may be infra-red active, that the Raman spectrum may contain reverse-polarized contributions and that both infra-red and Raman spectra may contain strong progressions of bands involving multiple excitations of the vibronically active vibration.

Resonance Raman labels: spectroscopic studies on cis- and trans-4-benzylidene-2-phenyl-Δ2 -oxazolin-5-one and an isotopically substituted analog

1978 ◽  
Vol 56 (2) ◽  
pp. 232-239 ◽  
Author(s):  
K. Kumar ◽  
D. J. Phelps ◽  
P. R. Carey
Keyword(s):  
Raman Spectra ◽  
Electronic Transition ◽  
Raman Band ◽  
Resonance Raman ◽  
Spectroscopic Studies ◽  
Trans Isomers ◽  
Absorption Bands ◽  
Cis And Trans Isomers ◽  
Raman Excitation Profiles ◽  
Cis And Trans

The absorption and preresonance Raman spectra of cis- and trans-4-benzylidene-2-phenyl-Δ2-oxazoIin-5-one are reported. Although steric considerations suggest that the π electron pathway in the cis isomer is considerably distorted compared to the trans isomer, the Raman and absorption spectra of the two isomers are strikingly similar. Preresonance Raman excitation profiles for the cis and trans isomers indicate that the main features in the Raman spectra owe their intensity to coupling to the 360 nm absorption band present in both isomers. It is proposed that both the electronic dipole transition responsible for this absorption and the vibrational modes giving rise to the intense Raman bands are localized in the —C=C—N=C—Ph part of the molecule. Thus the main Raman and absorption bands are insensitive to isomerization in the benzylidene portion. Support for a localized electronic transition, polarized along the —C=C—N=C—Ph long axis, comes from Raman depolarization ratio (ρ) measurements which show that ail intense Raman features in both cis and trans isomers have ρ ∼ 0.33. Further support comes from ir and resonance Raman spectra of trans-4-(4-dimethylamino-3-nitrobenzylidene)-2-phenyloxazolin-5-one substituted either with 13C in the 4 position, or with 15N, in the oxazolinone ring. These spectra indicate that the main Raman feature seen in all 4-benzylidene-2-phenyloxazolinonesat 1561 cm−1 is a symmetric stretching mode associated with the —C=C—N=C— chain and that this feature has some C=N stretching character. The substitution experiments also show that the weak 1654 cm−1 Raman band has a high degree of C=C stretching character and may represent an essentially antisymmetric mode from the C=C—N=C moiety. The preresonance Raman excitation profiles show that the intensity enhancement follows an FB2 type dependence. The utility of the Raman spectrum as a probe for the chromophore responsible for the electronic transition in a highly conjugated system is discussed.

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.

Vibrational Spectra of Sulphonyl Derivatives. V. A Reassignment of the SO2 Stretching Frequencies in Sulphonyl Fluorides

1960 ◽  
Vol 13 (4) ◽  
pp. 443 ◽  
Author(s):  
NS Ham ◽  
AN Hambly ◽  
RH Laby
Keyword(s):  
Vibrational Spectra ◽  
Vibrational Assignments ◽  
Infra Red ◽  
Methyl Benzene ◽  
Sulphonyl Fluoride

The symmetric SO2 stretching frequency in methane sulphonyl fluoride and a number of aromatic sulphonyl fluorides is reassigned to a frequency of 1210 cm-1 on the basis of new infra-red evidence (vapour and solution spectra of CH3SO2F and the infra-red spectra of a number of aromatic sulphonyl chlorides and the corresponding fluorides). Complete vibrational assignments for benzene sulphonyl chloride, benzene sulphonyl fluoride, and methyl benzene sulphonate are also given. The S-F stretching frequency appears as a strong infra-red band near 780 cm-1 and the aromatic sulphonyl frequency near 1090 cm-1 is identified as being more specifically characteristic of the Car-S bond.

scholarly journals The normal vibrations of carbonate and nitrate ions

1931 ◽  
Vol 134 (823) ◽  
pp. 265-277 ◽  
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Raman Effect ◽  
Normal Modes ◽  
Potassium Nitrate ◽  
Nitrate Ions ◽  
Carbonate Ion ◽  
Infra Red ◽  
Modes Of Vibration

When the Raman effect was first discovered, it was believed that every line in the Raman spectrum referred to some characteristic vibration of the scatter­ing molecule. Later the tendency was to regard the lines as due to transitions between states of vibration of the molecule, so that the energies corresponded not to energies of vibration directly, but to differences in the energy of vibra­tion of two different modes. It is now realised that the infra-red spectrum of a substance and the Raman spectrum which it scatters give complementary information. Certain modes of vibration are represented solely in the infra­red spectrum, others are found only in the Raman spectrum, while others may appear in both spectra. Quite early a rough criterion on the basis of symmetry was put forward by Schaefer, for the determination of whether or not a particular vibration was to be expected in the Raman effect. Recently a selection rule has been formulated by Placzek; no vibration will appear as a fundamental in the Raman effect if it is such that any symmetrical operation upon it can change the signs of the displacements of the normal co-ordinates, without altering the energy. It is clear that a knowledge of the normal modes of vibration of the molecule under discussion must precede the application of any such rule, and it is the purpose of the present communication to discuss the normal modes of vibration of the carbonate and nitrate ions. In 1929 the writer showed that it was possible to obtain Raman spectra from powdered crystals, and the discovery was made when using powdered crystals of potassium nitrate. The method was applied first to carbonates and nitrates, so it became of interest to attempt to fix the structure of the anions of these salts by means of the Raman spectra combined with the infra-red data. In what follows the carbonate ion will first be dealt with in some detail, and then the nitrate ion can be treated summarily owing to the similarity of structure of the two ions.

The Raman and infra-red spectra of carbon suboxide

1954 ◽  
Vol 223 (1153) ◽  
pp. 251-266 ◽  
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Malonic Acid ◽  
Mass Spectra ◽  
Linear Molecule ◽  
Molecular Symmetry ◽  
Carbon Suboxide ◽  
Photoelectric Recording ◽  
Infra Red

The infra-red and Raman spectra of carbon suboxide have been redetermined since earlier data did not permit an unequivocal decision as to the molecular symmetry. The infra-red spectrum of the gas was measured over the range 275 to 4600 cm -1 using a Perkin-Elmer spectrometer. The Raman spectrum of the liquid (at — 90° C) was investigated using a photoelectric recording spectrometer constructed in this laboratory. No trouble was experienced with decomposition of the sample. The purity of the suboxide which was prepared from malonic acid was carefully checked by following changes in the infra-red and mass spectra at various stages of the purification. In this way several bands previously attributed to the suboxide were shown to be due to impurities. Details of a normal co-ordinate treatment are given, and with its aid all the observed bands are given satisfactory assignments on the basis of a linear molecule, symmetry D ∞λ . This necessitates the postulation of one infra-red active fundamental at about 198 cm -1 . Though this lies outside the region investigated here it has recently been observed by O’Loane in the course of investigations on a series of compounds in the far infra-red.

The infra-red spectra of the Borate esters

1955 ◽  
Vol 8 (3) ◽  
pp. 355 ◽  
Author(s):  
RL Werner ◽  
KG O'Brien
Keyword(s):  
Absorption Band ◽  
Boric Acid ◽  
Raman Spectra ◽  
Raman Band ◽  
Methyl Groups ◽  
Group Comparison ◽  
Trimethyl Borate ◽  
Characteristic Absorption Band ◽  
Infra Red ◽  
High Degree

The infra-red spectra of a series of alkyl and aryl esters of boric acid have been obtained in the region from 1800 to 670 cm-1. These all show a strong characteristic absorption band at 1340 � 10 cm-1 which is assigned to the asymmetrical stretching frequency of the BO3 group. Comparison of the infra-red and Raman spectra of trimethyl borate suggests the assignment of the 728 cm-1 Raman band to the symmetrical stretching mode. The non-coincidence of infra-red and Raman bands indicates a fairly high degree of symmetry with restriction of the rotation of the methyl groups round the B-O link. This contrasts with other data on the behaviour in the vapour where such rotation may occur.

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 RAMAN SPECTRUM OF ETHANE

1955 ◽  
Vol 33 (10) ◽  
pp. 588-599 ◽  
Author(s):  
J. Romanko ◽  
T. Feldman ◽  
H. L. Welsh
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Spectral Resolution ◽  
Raman Band ◽  
Point Group ◽  
Infrared Band ◽  
Torsional Frequency

The rotational and rotation-vibrational Raman spectra of gaseous ethane at 1–3 atm. pressure have been photographed with a spectral resolution of approximately 1 cm.−1. Analyses of the rotational structures of the ν1 and ν2 totally symmetric bands were carried out; only the Q branch of the ν2 band was observed. The structures of the degenerate ν10 and ν11 bands were analyzed; however, no trace of ν12 was found. The structure of the ν10 band shows beyond doubt that the point group of the molecule is D3d. From the ν11+ν4 infrared band, and the ν11 Raman band, the value, 278.4 cm.−1, is deduced for the torsional frequency ν4.

THE RAMAN SPECTRA OF DEUTERATED METHYL LAURATES AND RELATED COMPOUNDS

1964 ◽  
Vol 42 (2) ◽  
pp. 305-325 ◽  
Author(s):  
R. Norman Jones ◽  
R. A. Ripley
Keyword(s):  
Raman Spectrum ◽  
Liquid Phase ◽  
Raman Spectra ◽  
Infrared Spectra ◽  
Minor Effect ◽  
Absorption Bands ◽  
Methyl Group ◽  
A Minor ◽  
Related Compounds ◽  
Methylene Group

The Raman spectra of methyl laurate and five derivatives selectively deuterated in the terminal methyl group, the α-methylene group, and the carbomethoxy group have been examined in the liquid phase. Raman spectra of n-dodecane and n-dodecane-1,12-d6 have also been determined. The spectra are compared with the infrared spectra, which have been reported previously, and are analyzed in terms of current views on the vibrations of compounds containing polymethylene chains.Whereas the infrared spectra of the esters are dominated by absorption bands associated with the carbomethoxy group, this group has only a minor effect on the Raman spectrum; the implications of this in organic structural analysis are discussed.

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