The Infrared Absorption Spectra of HCl in Benzene

Abstract
The infrared absorption of benzene and a solution of HCl in benzene has been measured in the region from 2.5μ to 4.2μ. The absorption band of benzene at about 3.38μ is increased in intensity and shifted to longer wave-lengths in the solution for the same cell thickness. Other benzene bands in the region from 2μ to 3μ did not show an appreciable change in intensity or position. It was concluded that the absorption in the region of 3.4μ was due to the HCl in solution. When the ratio of the absorption of the solution to the absorption of the benzene is found, there appears a band with center at about 3.49μ. The relation of the absorption to the dipole moment is discussed.