The Infrared Spectra of Amino Acids and Some Simple Polypeptides to 33 cm −1 at Room and Liquid Nitrogen Temperatures

Abstract

The ir spectra of a number of amino acids have been studied and the absorption bands in the 400–33 cm⁻¹ region are reported. Spectra were recorded at both room and liquid nitrogen temperatures. It was observed that recording at low temperatures is a useful method for obtaining additional analytical information when the amino acids are in the zwitterion form. Low temperature is also useful in determining the assignment of several of the low frequency bands.