INTERNAL ROTATION: VIII. THE INFRARED AND RAMAN SPECTRA OF FURFURAL

1955 ◽  
Vol 33 (6) ◽  
pp. 1055-1061 ◽  
Author(s):  
G. Allen ◽  
H. J. Bernstein
Keyword(s):  
Raman Spectrum ◽  
Infrared Spectrum ◽  
Equilibrium Mixture ◽  
Stable Form ◽  
Infrared And Raman Spectra ◽  
Dilute Solution ◽  
Electric Moment ◽  
Temperature Range ◽  
Planar Configuration ◽  
Rotational Isomers

The Raman spectrum of furfural has been obtained photoelectrically in the liquid over a temperature range of 50° and in solution. The infrared spectrum has been obtained for the solid, the liquid (over a temperature range of 90°), and in dilute solution over a 50° temperature range. The vibrational spectrum is interpreted in terms of an equilibrium mixture of two rotational isomers with planar configuration. The isomer with higher electric moment is the more stable form in the liquid and in the solid.

The Infrared and Raman Spectra of Trifluoronitrosomethane

1974 ◽  
Vol 52 (18) ◽  
pp. 3149-3157 ◽  
Author(s):  
Herbert F. Shurvell ◽  
Shiv C. Dass ◽  
Robert D. Gordon
Keyword(s):  
Raman Spectrum ◽  
Infrared Spectrum ◽  
Potential Energy ◽  
Internal Rotation ◽  
Condensed Phase ◽  
Infrared And Raman Spectra ◽  
Vibrational Assignment ◽  
Normal Coordinate ◽  
Energy Distributions ◽  
Torsional Mode

The infrared spectrum of gaseous CF3NO has been studied in the region 4000–35 cm−1. The infrared spectrum of the condensed phase has also been recorded and a complete vibrational assignment is proposed. Attempts to record the Raman spectrum have been hampered by photolysis. A frequency of 50 cm−1 for the CF3 torsional mode has been estimated from combination and hot bands. This corresponds to a barrier to internal rotation of approximately 425 cal/mol (150 cm−1). A normal coordinate analysis has been carried out and potential energy distributions, and valence and symmetry force constants are reported.

FAR INFRARED AND RAMAN SPECTRA AND STRUCTURE OF DITHIOPHOSGENE

1964 ◽  
Vol 42 (9) ◽  
pp. 2107-2112 ◽  
Author(s):  
W. K. Busfield ◽  
M. J. Taylor ◽  
E. Whalley
Keyword(s):  
Raman Spectrum ◽  
Infrared Spectrum ◽  
Raman Spectra ◽  
Far Infrared ◽  
Infrared And Raman Spectra ◽  
Tentative Assignment

The infrared spectrum in the range 3000–50 cm−1 and the Raman spectrum of solutions of dithiophosgene have been obtained. There are no coincidences in the infrared and Raman spectra, and the only structure consistent with this and approximately tetrahedral carbon valencies is[Formula: see text]that is tetrachloro-1,3-dithietane, in which the ring is planar or nearly planar. A tentative assignment of the observed bands is given on the basis of D2h symmetry.

Schwingungsspektren der Clusterverbindung Nb6F15/Vibrational Spectrum of the Cluster Compound Nb6F15

1989 ◽  
Vol 44 (1) ◽  
pp. 74-78 ◽  
Author(s):  
G. Kliche ◽  
H. G. von Schnering
Keyword(s):  
Raman Spectrum ◽  
Infrared Spectrum ◽  
Vibrational Spectrum ◽  
Raman Spectra ◽  
Metal Cluster ◽  
Cluster Compound ◽  
Vibrational Modes ◽  
Infrared And Raman Spectra ◽  
Normal Coordinate ◽  
Valence Force

Abstract Infrared and Raman spectra of the metal cluster compound [Nb6F12]F3 (cubic Im3̄m; Z = 2) are reported. The three intense m odes observed in the Raman spectrum at 215. 267, and 337 cm-1 and a weak mode observed in the infrared spectrum at 287 cm-1 are assigned to the T2g, Eg, A1g, and T1u vibrational modes of the Nb6 octahedra. The assignment is supported by normal coordinate analysis and Raman measurements at 47 kbar. The valence force constants are f(Nb-Fi) = 2.04, f(Nb-Fa-a) = 1.30 and f(Nb-Nb) = 0.97 N cm-1 metal-to-metal interaction in the cluster.

THE INFRARED AND RAMAN SPECTRA OF DISULPHUR DECAFLUORIDE (S2F10)

1957 ◽  
Vol 35 (3) ◽  
pp. 191-201 ◽  
Author(s):  
J. K. Wilmshurst ◽  
H. J. Bernstein
Keyword(s):  
Raman Spectrum ◽  
Infrared Spectrum ◽  
Potential Energy ◽  
Liquid Nitrogen ◽  
Potential Barrier ◽  
Energy Calculation ◽  
Infrared And Raman Spectra ◽  
Vibrational Assignment ◽  
Torsional Frequency ◽  
Simple Potential

The infrared spectrum of S2F10 has been obtained for the vapor from 5 to 35 μ and for the solid at liquid nitrogen temperatures from 10 to 24 μ. The Raman spectrum, together with depolarization ratios, was obtained for the liquid. A vibrational assignment has been made consistent with either D4d or D4h, symmetry and all the fundamentals identified except two low FSSF bending frequencies and the inactive torsional frequency. A normal co-ordinate calculation located the bending frequencies at 37 and 57 cm.−1 while a simple potential energy calculation gave a torsional frequency of 89 cm.−1 corresponding to a potential barrier of 2780 cm.−1.

INFRARED AND RAMAN SPECTRA OF TETRABROMOETHYLENE

1953 ◽  
Vol 31 (12) ◽  
pp. 1223-1228 ◽  
Author(s):  
F. E. Malherbe ◽  
G. Allen ◽  
H. J. Bernstein
Keyword(s):  
Raman Spectrum ◽  
Infrared Spectrum ◽  
Raman Spectra ◽  
Liquid State ◽  
Potential Functions ◽  
Infrared And Raman Spectra ◽  
Vibration Frequencies

The infrared spectrum of liquid and dissolved tetrabromoethylene has been investigated from 3µ–36µ. The Raman spectrum has been obtained photographically in the liquid state and photoelectrically in solution and depolarizations measured. All of the fundamentals were observed except v4, v7, v10, and v12. The last two vibration frequencies are estimated by calculations from two different potential functions.

CONFORMATIONAL EQUILIBRIA IN OPEN-CHAIN α,β-UNSATURATED KETONES

1961 ◽  
Vol 39 (11) ◽  
pp. 2225-2235 ◽  
Author(s):  
K. Noack ◽  
R. Norman Jones
Keyword(s):  
Raman Spectra ◽  
Equilibrium Mixture ◽  
Infrared And Raman Spectra ◽  
Temperature Dependent ◽  
Trans Form ◽  
Open Chain ◽  
Unsaturated Ketones ◽  
Conformational Isomers ◽  
Alkyl Substitution ◽  
Conformational Equilibria

The infrared and Raman spectra of trans-Δ3-penten-2-one have been measured over the temperature range +30° to −75° and +85° to +5° respectively. The temperature-dependent changes observed in the spectra indicate that this ketone exists as an equilibrium mixture of s-cis and s-trans conformational isomers in the liquid state. The s-trans form is the more stable and is present exclusively in the crystalline solid.Similar measurements have been carried out on Δ3-buten-2-one. The infrared and Raman spectra of this ketone also exhibit temperature effects that can be explained by a similar equilibrium, though the evidence is not as conclusive as for trans-Δ3-penten-2-one.The influence of alkyl substitution at the α- and β-carbon atoms on the relative stability of the s-cis and s-trans forms of α,β-unsaturated ketones is discussed.

Alterations in the Infrared Spectrum (2–15 μ) of Some Ketones at the Transition Liquid—Solid in the Low-Temperature Range

1968 ◽  
Vol 22 (6) ◽  
pp. 689-693 ◽  
Author(s):  
R. Caspary
Keyword(s):  
Low Temperature ◽  
Infrared Spectrum ◽  
Temperature Range ◽  
Work Characteristic

In this work characteristic alterations in the spectrum of some ketones are described resulting from the transition liquid—solid and from the influence of further lowering of the temperature.

scholarly journals The Interplay of Structure and Dynamics in the Raman Spectrum of Liquid Water over the Full Frequency and Temperature Range

2018 ◽  
Vol 9 (4) ◽  
pp. 851-857 ◽  
Author(s):  
Tobias Morawietz ◽  
Ondrej Marsalek ◽  
Shannon R. Pattenaude ◽  
Louis M. Streacker ◽  
Dor Ben-Amotz ◽  
...  
Keyword(s):  
Raman Spectrum ◽  
Liquid Water ◽  
Temperature Range ◽  
Structure And Dynamics

31P-NMR-Untersuchungen an linearen Phosphorylphosphazenen / 31P NMR Investigations oil Linear Phosphorylphosphazenes

1982 ◽  
Vol 37 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Gerhard Schilling ◽  
Claus W. Rabener ◽  
Wendel Lehr
Keyword(s):  
Small Molecules ◽  
Nmr Spectra ◽  
31P Nmr ◽  
Temperature Range ◽  
Rotational Isomers ◽  
Relaxation Effects ◽  
Homologous Compounds

Abstract The 31P NMR Spectra of PCl3NPCl2O (1) and the homologous compounds 2-4 do not indicate any rotational isomers in the temperature range 183-413 K. The observed values for ν/2 depend on the viscosity of the solvent and on the temperature of the sample. They are reduced to T1 relaxation effects, where the spin rotational mechanism may be dominant in the case of the small molecules and the PCl3 group.

scholarly journals Evolution Mechanism of Macromolecular Structure in Coal during Heat Treatment: Based on FTIR and XRD In Situ Analysis Techniques

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Dun Wu ◽  
Wenyong Zhang
Keyword(s):  
Heat Treatment ◽  
Infrared Spectroscopy ◽  
Infrared Spectrum ◽  
Functional Groups ◽  
Coal Sample ◽  
Diffraction Peak ◽  
Coal Rank ◽  
Coal Structure ◽  
Temperature Range

Owing to the complexity and heterogeneity of coal during pyrolysis, the ex situ analytical techniques cannot accurately reflect the real coal pyrolysis process. In this study, according to the joint investigation of Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), the structural evolution characteristics of lignite-subbituminous coal-bituminous coal-anthracite series under heat treatment were discussed in depth. The results of the infrared spectrum of coal show that the different functional groups of coal show different changes with the increase of coal rank before pyrolysis experiment. Based on in situ infrared spectroscopy experiments, it was found that the infrared spectrum curves of the same coal sample have obvious changes at different pyrolysis temperatures. As a whole, when the pyrolysis temperature is between 400 and 500°C, the coal structure can be greatly changed. By fitting the infrared spectrum curve, the infrared spectrum parameters of coal were obtained. With the change of temperature, these parameters show regular changes in coal with different ranks. In the XRD study of coal, the absorption intensity of the diffraction peak (002) of coal increases with increasing coal rank. The XRD patterns of coal have different characteristics at different pyrolysis temperatures. Overall, the area of (002) diffraction peak of the same coal sample increases obviously with the increase of temperature. The XRD structural parameter of coal was obtained by using the curve fitting method. The changing process of two parameters (interlayer spacing (d002) and stacking height (Lc)) can be divided into two main stages, but the average lateral size (La) does not change significantly and remains at the 2.98 ± 0.09 nm. In summary, the above two technologies complement each other in the study of coal structure. The temperature range of both experiments is different, but the XRD parameters of coal with different ranks are reduced within the temperature range of less than 500°C, which reflects that the size of coal-heated aromatic ring lamellae is reduced and the distance between lamellae is also reduced, indicating that the degree of condensation of coal aromatic nuclei may be increased. Correspondingly, the FTIR parameters of coal also reflect that, with increasing temperature, the side chains of coal are constantly cracked, the oxygen-containing functional groups are reduced, and the degree of aromatization of coal may be increased.

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