Raman Spectra of a Series of Normal Alcohols and Other Compounds

Abstract

The Raman spectra of benzene, cyclohexane, cyclohexene, carbon disulfide, butyl bromide and the normal alcohols from C${\mathrm{H}}_3$OH to ${\mathrm{C}}_{12}$ ${\mathrm{H}}_{25}$OH were investigated. The technique recently developed by Wood was used in conjunction with a praseodymium filter. New lines were found in all cases and for some compounds the number was nearly doubled. Two new frequencies at 2660 and 2730 ${\mathrm{cm}}^{-1\mathrm{}}$ were found in the spectra of essentially all the alcohols and butyl bromide. They appear to be characteristic of the saturated hydrocarbons. The lines which appear in the Raman spectra of the aliphatic hydrocarbons at 1450 and 1300 ${\mathrm{cm}}^{-1\mathrm{}}$ have been attributed respectively to the transverse vibrations of the hydrogens of the C${\mathrm{H}}_3$ and C${\mathrm{H}}_2$ groups. The line appearing in the Raman spectra of the alcohols at 1270 ${\mathrm{cm}}^{-1\mathrm{}}$ is attributed to the transverse vibrations of the hydrogens of the C${\mathrm{H}}_2$OH groups. It is pointed out that the Raman spectra of ${\mathrm{C}}_{12}$ ${\mathrm{H}}_{25}$OH is that of an infinitely long normal alcohol. The new lines of benzene reported by Weiler and Krishnamurti were verified with the exception of the 806 ${\mathrm{cm}}^{-1\mathrm{}}$ frequency. In addition a new line at 1690 ${\mathrm{cm}}^{-1\mathrm{}}$ was found. The two relatively strong lines of C${\mathrm{S}}_2$ at 650 and 800 ${\mathrm{cm}}^{-1\mathrm{}}$ were each found to be doublet, thus completing the analogy with C${\mathrm{O}}_2$. The separation of the components in each case was 10 ${\mathrm{cm}}^{-1\mathrm{}}$. The existence of a line at 391 ${\mathrm{cm}}^{-1\mathrm{}}$, originally reported by Bhagavantam, was verified.