Characterization of Carboxylic Acids: Identification of Their Anilide Derivatives by X-ray Diffractometry

Abstract

In order to extend the data available for the characterization of carboxylic acids, an x-ray diffraction technique has been used for the identification of their anilide derivatives. This technique often makes possible the identification of carboxylic acids that cannot be examined readily by other techniques such as gas chromotography and mass spectrometry. Reference x-ray diffraction patterns have been obtained for the anilide derivatives of 32 carboxylic acids containing up to 18 carbon atoms. Detailed descriptions are given for obtaining and qualitatively using the x-ray diffraction patterns of these anilides. The x-ray diffraction patterns of these anilides are unique; even closely related acids which differ only in isomeric form produce anilide derivatives which exhibit different and characteristic x-ray diffraction patterns. In the qualitative analysis of single or multicomponent carboxylic acid-containing mixtures, this x-ray diffraction technique is used either alone or with infrared spectrometric techniques.