POLYMORPHISM IN ETHYL-ESTERS OF N-ACETYLGLYCINE OLIGOMERS - A STUDY BY VIBRATIONAL SPECTROSCOPY

Ethyl esters of N-acetylglycine oligomers from tbe trimer to nonamer w ere prepared and vibrational spectra in the solid state were measured. Vibrational band assignments were made on the basis of the assignment s for polyglycine I, polyglycine II and N-acetylglycine oligomers. For ethyl esters of N-acetylglycine from the trimer to pentamer, a struct ure similar to that of polyglycine II was obtained For the hexamer and longer oligomers, structural transformations similar to those for pol yglycine I and polyglycine II was observed. X-ray powder diffraction p atterns were also measured to confirm the structures of these oligomer s. (C) 1997 by John Wiley & Sons, Ltd.