The Infrared Absorption of Cyanides and Thiocyanates

Abstract

Aqueous solutions of seven inorganic cyanides, two thiocyanates, and one cyanate were studied in the region from 1.2μ to 7.5μ. Two organic cyanides and an organic thiocyanate were studied in the same region. In all the materials a characteristic absorption band was observed in the region from 4.38μ to 4.90μ. The exact position of the band was found to be different for the various substances. This characteristic absorption was attributed to changes in the vibrational energy of the bound CN group. An additional band appearing only in the highly ionized cyanide solutions was attributed to the free CN ions. In the cyanate solution a double band appeared in the region of 7μ which was not characteristic of the cyanide or thiocyanate solutions. Hydrolysis and solvation effects were observed in some of the solutions.