A New OH Band in a Carboxylic Acid

Abstract

RECENT investigations of infra-red, spectra in the region of 3 μ by Davies and Sutherland¹, and Buswell, Rodebush and Roy², have shown that the COOH group of carboxylic acids has an absorption band close to that given by the OH group in alcohols and phenols³ (˜2.8μ) as well as a large region of absorption at longer wave-lengths. There is, however, an important distinction between the acids and other compounds. While alcoholic and phenolic bodies are generally unassociated in carbon tetrachloride at concentrations of 0.01 mol./l. and lower (compounds such as salicylic aldehyde are exceptions and are completely associated intramolecularly), the acids are much more strongly associated and intense absorption in the association region is found at concentrations so low as 0.002 mol./l. at ordinary temperatures.