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 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.

scholarly journals The constitution of water in different states

1934 ◽  
Vol 145 (855) ◽  
pp. 489-508 ◽  
Keyword(s):  
Absorption Band ◽  
Water Vapour ◽  
Relative Intensity ◽  
Liquid State ◽  
Raman Band ◽  
Water Band ◽  
Infra Red ◽  
Triple H ◽  
Increasing Temperature ◽  
Three Components

In a previous communication, the author described the behaviour of water with changes of temperature and with addition of electrolytes as revealed by the changes in the structure of its Raman band. This band is found to consist of three components with mean Raman frequencies 3217, 3433, and 3582 cm. -1 . With increasing temperature, the component 3582 increased in intensity, while the first diminished, the central one remaining nearly constant. A comparison of the above changes with the results obtained by the author for ice indicated that the component which becomes more intense with increasing temperature is absent in the Raman band of ice. The first component with the smallest Raman frequency, however, is very conspicuous in ice, and the central one retains the same relative intensity. The above differences in the structure of the band were explained on the hypothesis that water consists not only of single (H 2 O) but also of double (H 2 O) 2 and triple (H 2 O) 3 molecules, the relative proportions of which depend upon its state of aggregation as well as on its temperature. Ice is supposed to consist only of double and triple molecules, which reveal themselves as the two components of its Raman band. In the liquid state, the presence of all the three components in this band is taken as evidence of the fact that there are all the three types of molecules in this state. No data were then available as regards the Raman band for water-vapour. But the infra-red absorption band observed by Hettner at 2.66 μ has its corresponding component in the water band which is supposed to arise out of the single H 2 O molecules.

RAMAN SPECTRA OF TITANIUM DI-, TRI-, AND TETRA-CHLORIDES

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3865-3868 ◽  
Author(s):  
H. MIYAOKA ◽  
T. KUZE ◽  
H. SANO ◽  
H. MORI ◽  
G. MIZUTANI ◽  
...  
Keyword(s):  
Force Constant ◽  
Raman Spectra ◽  
Normal Mode ◽  
Raman Band ◽  
Normal Mode Analysis ◽  
Force Constants ◽  
Mode Analysis ◽  
Oxidation Number

We have obtained the Raman spectra of TiCl n (n= 2, 3, and 4). Assignments of the observed Raman bands were made by a normal mode analysis. The force constants were determined from the observed Raman band frequencies. We have found that the Ti-Cl stretching force constant increases as the oxidation number of the Ti species increases.

Characterization of SrBi2Nb2O9 Thin Films Prepared by Sol Gel Technique

1996 ◽  
Vol 459 ◽  
Author(s):  
E. Ching-Prado ◽  
W. Pérez ◽  
A. Reynés-Figueroa ◽  
R. S. Katiyar ◽  
D. Ravichandran ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Band ◽  
Sol Gel ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Gel Technique ◽  
High Degree ◽  
First Time

ABSTRACTThin films of SrBi2Nb2O9 (SBN) with thicknesses of 0.1, 0.2, and 0.4 μ were grown by Sol-gel technique on silicon, and annealed at 650°C. The SBN films were investigated by Raman scatering for the first time. Raman spectra in some of the samples present bands around 60, 167, 196, 222, 302, 451, 560, 771, 837, and 863 cm−1, which correspond to the SBN formation. The study indicates that the films are inhomogeneous, and only in samples with thicknesses 0.4 μ the SBN material was found in some places. The prominent Raman band around 870 cm−1, which is the A1g mode of the orthorhombic symmetry, is assigned to the symmetric stretching of the NbO6 octahedrals. The frequency of this band is found to shift in different places in the same sample, as well as from sample to sample. The frequency shifts and the width of the Raman bands are discussed in term of ions in non-equilibrium positions. FT-IR spectra reveal a sharp peak at 1260 cm−1, and two broad bands around 995 and 772 cm−1. The bandwidths of the latter two bands are believed to be associated with the presence of a high degree of defects in the films. The experimental results of the SBN films are compared with those obtained in SBT (T=Ta) films. X-ray diffraction and SEM techniques are also used for the structural characterization.

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.

scholarly journals Graphene Domain Signature of Raman Spectra of sp2 Amorphous Carbons

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2021
Author(s):  
Elena F. Sheka ◽  
Yevgeny A. Golubev ◽  
Nadezhda A. Popova
Keyword(s):  
Raman Spectra ◽  
Molecular Spectroscopy ◽  
Basic Structure ◽  
Quasi Particle ◽  
Phonon Spectra ◽  
2D Pattern ◽  
Density Delocalization ◽  
Electron Density Delocalization ◽  
High Degree

The standard D-G-2D pattern of Raman spectra of sp2 amorphous carbons is considered from the viewpoint of graphene domains presenting their basic structure units (BSUs) in terms of molecular spectroscopy. The molecular approximation allows connecting the characteristic D-G doublet spectra image of one-phonon spectra with a considerable dispersion of the C=C bond lengths within graphene domains, governed by size, heteroatom necklace of BSUs as well as BSUs packing. The interpretation of 2D two-phonon spectra reveals a particular role of electrical anharmonicity in the spectra formation and attributes this effect to a high degree of the electron density delocalization in graphene domains. A size-stimulated transition from molecular to quasi-particle phonon consideration of Raman spectra was experimentally traced, which allowed evaluation of a free path of optical phonons in graphene crystal.

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