The Intensity of the Carbonyl Band in the Infrared Spectra of Methyl Benzoates

J. L. MATEOS; R. CETINA; E. OLIVERA; S. MEZA

doi:10.1021/jo01351a085

The split carbonyl band in the infrared spectra of halogen derivatives of 4-hydroxy-2,4-pentadienoic acid lactone

Tetrahedron ◽

10.1016/s0040-4020(01)90723-9 ◽

1971 ◽

Vol 27 (3) ◽

pp. 543-548 ◽

Cited By ~ 7

Author(s):

A. Winston ◽

R.N. Kemper

Keyword(s):

Infrared Spectra ◽

Carbonyl Band ◽

Pentadienoic Acid ◽

Acid Lactone ◽

Derivatives Of

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Infrared spectra of 2α-substituted 3-oxotriterpenoids and conformation of ring A

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19910966 ◽

1991 ◽

Vol 56 (5) ◽

pp. 966-972 ◽

Cited By ~ 1

Author(s):

Jiří Klinot ◽

Stanislav Hilgard ◽

Jakub Krijt ◽

Petr Olšovský

Keyword(s):

Infrared Spectra ◽

Carbonyl Band ◽

Polar Substituent

Infrared spectra of triterpenoid 19β,28-epoxy-18α-oleanane 3-ketones I - VI in the region of carbonyl stretching frequencies have been studied. Comparison of the spectra of crystals with those of solutions in various solvents, together with comparison of fundamental C=O frequencies with their first overtone leads to the conclusion that the doublet character of the carbonyl band in the solution of ketones I - IV with polar substituent in position 2α is caused by the chair-boat equilibrium of the ring A.

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THE CARBONYL STRETCHING BANDS IN THE INFRARED SPECTRA OF UNSATURATED LACTONES

Canadian Journal of Chemistry ◽

10.1139/v59-293 ◽

1959 ◽

Vol 37 (12) ◽

pp. 2007-2022 ◽

Cited By ~ 150

Author(s):

R. N. Jones ◽

C. L. Angell ◽

T. Ito ◽

R. J. D. Smith

Keyword(s):

Infrared Spectra ◽

Carbonyl Compounds ◽

Structural Features ◽

Membered Ring ◽

Fermi Resonance ◽

Fundamental Vibration ◽

Conformational Isomers ◽

Band Splitting ◽

Carbonyl Band ◽

Unsaturated Lactones

Certain types of unsaturated lactones exhibit two bands in the region of the spectrum associated with the C=O stretching vibrational mode. This is observed both in the infrared and Raman spectra.The infrared spectra of 23 simple saturated and unsaturated lactones have been examined in an attempt to determine the structural features with which this carbonyl band splitting is associated. It appears to be common to most unsaturated five- and six-membered ring lactones in which the double bond is conjugated with the carbonyl group, though one well-established exception has been observed. The relative intensities of the two bands are extremely sensitive to changes in the polarity of the solvent; they also vary reversibly with temperature but are independent of concentration.The splitting of the C=O stretching band is attributed to an intramolecular vibrational effect similar to that which occurs in cyclopentanone and in certain Δ2-cyclopentenone derivatives. Its possible dependence on Fermi resonance with the overtone of a lower lying fundamental vibration is discussed.Similar effects occur in other types of carbonyl compounds, such as benzoyl chloride and cyclic five-membered ring anhydrides, and care is needed to distinguish carbonyl band splitting of this kind from that associated with equilibria between conformational isomers.

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Infrared spectra of substituted benzoyl chlorides and benzoyl bromides. Explanation of the anomalous carbonyl band-splittings

Spectrochimica Acta ◽

10.1016/s0371-1951(62)80135-0 ◽

1962 ◽

Vol 18 (3) ◽

pp. 273-278 ◽

Cited By ~ 32

Author(s):

C.N.R. Rao ◽

R. Venkataraghavan

Keyword(s):

Infrared Spectra ◽

Carbonyl Band ◽

Benzoyl Chlorides

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Some Comments on the Infrared Spectra of Vapors

Applied Spectroscopy ◽

10.1366/000370268774384119 ◽

1968 ◽

Vol 22 (6) ◽

pp. 678-688 ◽

Cited By ~ 9

Author(s):

David Welti ◽

Rainer Stephany

Keyword(s):

Hydrogen Bonding ◽

Infrared Spectra ◽

Carbonyl Compounds ◽

Liquid Solution ◽

Dilute Solutions ◽

Carbonyl Band ◽

Selection Of

The bands in ir vapor spectra shift from their frequency positions in liquid, solution, or solid spectra according to the extent of the interaction of the sample with the solvent or other solute or condensed molecules. The most noticeable differences occur with hydrogen bonding compounds, where the vapor spectra are analogous to the spectra of very dilute solutions and can be correlated with the presence of free monomers, particularly at higher vapor temperatures. The spectra of alcohols, phenols, acids, amines, and amides have been obtained at temperatures ranging from 80°–190°C. The frequencies of the typical bands are tabulated. The carbonyl band frequencies of a selection of carbonyl compounds are also tabulated.

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