INFRARED STUDY OF THE ASSOCIATION OF CHLOROFORM AND TRIETHYLAMINE

Abstract

“The association between chloroform and triethylamine was studied using infrared techniques with particular attention to the assignment of the absorption near $2500 cm^{-1}$. The infrared spectra show typical features associated with hydrogen bonding. The frequency of the C-H stretching mode of chloroform is shifted to approximately $2850 cm^{-1}$ in the complex. In addition, another band appears near $2500 cm^{-1}$. When $CDCl_{3}$ is used instead of $CHCl_{3}$ the frequencies of both bands are decreased by factors near 1.35. This shows that the hydrogen atom in chloroform is involved in each absorption. The intensity ratio of the two bands remains constant when the proportions of $CDCl_{3}$ and ($C_{2}H_{5})_{3} N$ are varied by a factor of ten. These features are in the spectra of solids prepared by freezing the mixed vapors. Deposition does not alter the relative intensities either at $20^{\circ} K$ or $77^{\circ} K$. Possible explanations for the presence of the two bands are examined, including the possibility that a double minimum exists in the potential curve for the hydrogen atom stretching motion.”