Some Speculations Concerning the Low Frequency Vibrations in the Infrared Spectra of C19-Ketosteroids

1955 ◽  
Vol 77 (23) ◽  
pp. 6331-6340 ◽  
Author(s):  
R. Norman Jones ◽  
B. Nolin ◽  
G. Roberts
Keyword(s):  
Infrared Spectra ◽  
Low Frequency

Far Infrared Group Frequencies. V. Oximes and Aldoximes

1973 ◽  
Vol 27 (1) ◽  
pp. 22-26 ◽  
Author(s):  
S. M. Craven ◽  
F. F. Bentley ◽  
D. F. Pensenstadler
Keyword(s):  
Hydrogen Bond ◽  
Infrared Spectra ◽  
Low Frequency ◽  
Far Infrared ◽  
Torsional Vibrations ◽  
Lattice Vibrations ◽  
Dilute Solutions ◽  
Solid Samples ◽  
Bending Modes ◽  
Bond Stretch

The low frequency infrared spectra from 450 to 75 cm−1 of seven oximes and five aldoximes have been recorded for pure samples and for dilute solutions in cyclohexane. An intense characteristic band is present in the solution spectra at 367 ± 10 cm−1. This characteristic band shifts to 275 ± 10 cm−1 in the spectra of the OD compounds. The 367 ± 10 cm−1 and 275 ± 10 cm−1 bands are assigned to OH and OD torsional vibrations. A comparison of the solution spectra with spectra of the solid samples indicated that the OH … N hydrogen bond stretch of oximes and aldoximes occurs in 300 to 200 cm−1 region. Strong bands also are present in 140 to 100 cm−1 region which are due to OH … N bending modes or perhaps lattice vibrations.

Investigation of Spectral Sensitization III. A Study of the Visible and Infrared Spectra of Some Very Pure Bis-Thiazolinyl and Bis-Thiazolyl Cyanine Iodides

1966 ◽  
Vol 20 (3) ◽  
pp. 150-158 ◽  
Author(s):  
A. Leifer ◽  
M. Boedner ◽  
P. Dougherty ◽  
A. Fusco ◽  
M. Koral ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Low Frequency ◽  
Red Shift ◽  
Absorption Bands ◽  
Spin Resonance ◽  
Visible Spectra ◽  
Bond System ◽  
Phenyl Rings ◽  
In Series ◽  
Systematic Group

A detailed study of the visible spectra in solution and the infrared spectra of the dyes in the solid state have been made for the following vinylogous series of cyanine dyes: [2-bis(3-ethylthiazolinyl)] cyanine iodides, I; [2-bis(3-ethyl-4-methylthiazolyl)] cyanine iodides, II; and [2-bis(3-ethyl-4,5-diphenylthiozolyl] cyanine iodides, III. Each dye, to be acceptable for study, had to be chromatographically pure, give a correct microchemical elemental analysis, and be free of electron-spin resonance (free radical) signals. These vinylogous series of dyes form a systematic group. That is, in series I there is only a resonant conjugated chain of alternate single and double bonds present between the two nitrogen atoms; in series II there are additional olefinic unsaturated bonds which are in conjugation with the resonant conjugated chain; and in series III there are additional phenyl rings in conjugation with the entire pi bond system present in II. The characteristic red shift of the principal absorption maxima was observed for these dyes in the visible as the number of methine linkages increased. Furthermore, a small relative red shift of the absorption maxima has been observed for this group of dyes and has been interpreted on the basis of the type of unsaturation present in conjugation with the resonant conjugated chain. Assignments of vibrational modes to separate absorption regions have been made for these vinylogous series of dyes. A correlation of the dye structure with the absorption bands has been made. Each vinylog gave rise to a characteristic pattern of resonant conjugated stretching modes in the region 1600 to 1400 cm−1. These modes exhibited a low frequency shift as the resonant conjugated chain-length increased. For a constant number of polymethine linkages these modes are a function of the type of unsaturation present which is in conjugation with the resonant conjugated chain.

The Preparation and Low-Frequency Vibrational Spectra of Some Copper(I) and Silver(I) Alkane- and Arene-monothiolate Complexes

1979 ◽  
Vol 32 (7) ◽  
pp. 1443 ◽  
Author(s):  
GA Bowmaker ◽  
L Tan
Keyword(s):  
Raman Spectra ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Low Frequency ◽  
Far Infrared ◽  
New Methods ◽  
Thiolate Complexes ◽  
New Compounds ◽  
First Time ◽  
Far Infrared Spectra

A number of different methods for preparing anionic Group 1B metal thiolate complexes have been investigated. The compounds [Me4N] [CU2(SMe)3] and [Et4N] [Ag5(SBut)6] are reported for the first time, and new methods for preparing the previously known compounds [Et4N] [Cu5(SBut)6], [Me4N]2 [CU5(SPh)7] and [Et4N]2 [Cu5(SPh)7] are described. The far-infrared spectra of the above compounds, and of CuSMe, CuSBut, AgSBut, [Me4N]2 [CU4(SPh)6] and [Me4N]2 [Ag5(SPh)7] have been obtained, and metal-sulfur stretching bands are assigned in the 150-350 cm-1 region. The low-frequency Raman spectra have also been obtained for some of these compounds. Possible structures for the new compounds are considered in the light of the low-frequency vibrational spectra.

Low-Frequency Infrared Spectra of Aliphatic Monocarboxylic Acids

1968 ◽  
Vol 22 (4) ◽  
pp. 286-294 ◽  
Author(s):  
J. E. Saunders ◽  
F. F. Bentley ◽  
J. E. Katon
Keyword(s):  
Infrared Spectra ◽  
Low Frequency ◽  
Pure Liquid ◽  
Vibrational Modes ◽  
Monocarboxylic Acids ◽  
Strongly Coupled ◽  
Dimer Structure ◽  
Raman Intensities ◽  
Infrared And Raman Intensities

The infrared spectra of a number of aliphatic monocarboxylic acids in the 350–50 cm−1 range are reported and several consistencies in band frequencies noted. An attempt to assign the low frequency vibrational modes of some of the simpler acids has been made based on infrared and Raman intensities. It is concluded that these molecules consist of relatively strongly coupled dimer molecules in the pure liquid and that the spectra reflect this dimer structure.

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