Alcohol Spectrum Research Articles

Mass spectra and organic analysis. Part VII. The mass spectra of the menthols, carvomenthols, their acetates and related alcohols

The mass spectra of the saturated p-menthane alcohols are described. Fission occurs preferentially around the carbinol carbon and adjacent to the ring substituents. The tertiary alcohols lose water less readily than the secondary alcohols. Loss of methyl is appreciable in only one case (menth-1-ol). The stereochemical isomers of menthol and carvomenthol are readily distinguished by their mass spectra. The acetates of menthol and carvo-menthol behave quite differently, resembling the menthenes formed from them by loss of acetic acid in a 1,2-elimination. Many of the hypothetical fragmentations were confirmed by deuteration studies.

Near-infrared absorption spectra of hydroxylated steroids and other alcohols

Near-infrared absorption spectra of over 30 hydroxylated steroids dissolved in carbon disulfide were obtained with the Beckman DK-2 spectrophotometer. The use of microcuvettes made possible an analysis on less than 50 μg of steroid. The free hydroxyl group in the secondary and tertiary alcohols absorbed maximally at 2764–2772 mμ with extinction coefficients of 32–56 l/mole-cm, both parameters being affected by the position of the hydroxyl group. Hydroxyl groups attached to a carbon forming part of an epoxy linkage absorbed maximally at 2788–2798 mμ. α-Diols yielded doublets in specific locations, indicating intramolecular hydrogen bonding. 21-Hydroxy- and 17α-hydroxy-20-ketones gave broad bands with maximum absorption at 2867 and at 2843–2857 mμ, respectively, also ascribed to intramolecular hydrogen bonding. Suspensions of hydroxylated steroids in carbon disulfide also yielded characteristic spectra that differed from those of steroids in solution. The spectra of various non-steroid alcohols and diols dissolved in carbon disulfide were determined for comparison with those of hydroxylated steroids.

The Raman spectra of organic compounds

The Raman spectra of methyl alcohol, ethyl alcohol,n-propyl alcohol andn-butyl alcohol have been recorded using λ 2537 excitation. 35, 49, 45 and 51 Raman lines respectively have been identified in the spectra of these alcohols, in addition to the rotational ‘wings’. In each case, a large number of additional lines have been recorded. The existence of Raman lines with frequency shifts greater than 3800 cm.−1, first reported by Bolla in the spectrum of ethyl alcohol, has been confirmed. Similar high-frequency shift Raman lines have also been recorded in the spectrum of methyl alcohol. They have been assigned as combinations. Proper assignments have been given for the prominent Raman lines appearing in the spectra of these alcohols.

Hydrogen Bond: An Experimental Verification of the Double Minimum Potential

The spectra of alcohols in the region of the first and second OH stretching overtone in solvents of various bonding strengths reveal a pair of solvent dependent absorption bands. These bands are shown to arise from an energy level splitting resulting from a double minimum in the potential energy curve for the proton. The form that the potential energy curve must assume to yield the observed spectra is such that the second minimum lies in the region of the v=2 vibrational energy level for ordinary hydrogen bonding situations. The higher overtone bands, particularly in strongly basic solvents, are characteristic of the broad potential well. This observed splitting of the absorption bands of hydrogen bonded alcohols confirms the theoretical predictions of a double minimum potential energy function for the proton.

Electron resonance studies of the change in free radical spectra of solid alcohols with variation of temperature and time of U.-V. irradiation

Electron resonance studies of the change in free radical spectra of solid alcohols with variation of temperature and time of U.-V. irradiation

THE MICROWAVE ABSORPTION SPECTRUM OF METHYL ALCOHOL

The microwave absorption spectrum of methyl alcohol was studied in the region 23,400 to 25,200 Mc., using a double modulation system in which the usual radio-frequency sine wave was replaced by a sharp, pip-shaped pulse with a repetition rate of 55 kc. Twenty-five new lines were found and these, along with those previously reported outside the region examined, were grouped into four series. When the methyl alcohol was mixed with a large percentage of water vapor the spectrum was found to be modified considerably.

Intensity and Polarization of Brillouin Spectra*

Apparatus is described for the production of intense Brillouin spectra. The fine structure of the transverse scattered light (Rayleigh scattering) has been analyzed by means of a large Fabry and Perot etalon placed in the parallel beam of a high aperture glass spectrograph. Interferograms have been obtained of the Brillouin spectrum of acetone, ethyl alcohol, and water using λ4078 of Hg as the exciting line. Intensity measurements of these interference patterns show that the theory of Landau and Placzek is a very close approximation to the truth in the spectra investigated.Polarization measurements have been made on these spectra excited by λ4358Hg by means of the method of Douglas and Rank. These polarization measurements show that ρs is small but not zero for the modified Brillouin components. The polarization of the unmodified Brillouin components seems to be somewhat less complete than that of the modified components. However the polarization measurements on the unmodified lines are vitiated by parasitic light and are not nearly as reliable as measurements on the modified lines.

Raman spectra of methyl alcohol, ethyl alcohol andn-heptane

Raman spectra of methyl alcohol, ethyl alcohol andn-heptane

First-Order Stark Effect in the Microwave Spectrum of Methyl Alcohol

First-Order Stark Effect in the Microwave Spectrum of Methyl Alcohol

The Infrared Absorption Spectrum of Water and Alcohols in Nonpolar Solvents

The Infrared Absorption Spectrum of Water and Alcohols in Nonpolar Solvents

On the Infrared Absorption Spectra of Several Gases

The spectra of acetylene, ethylene, n-butane, n-hexane, n-octane, benzene, toluene, cumene, ethyl alcohol, ethyl ether, and sulphur dioxide were investigated with a grating of 1134 lines per cm in the region between 3 and 4 μ. The absorption curves are represented in figures. A table gives the wave-numbers of the maxima and selected wave-number differences. The individual lines of the bands are not revealed, but the envelopes are obtained. From the latter an attempt is made to state what branches are present in the bands. Attention is called to relations existing among the wave-number differences.