
%0 Journal Article
%A Hughes, Andrew B. 
%A Mackay, Maureen F. 
%A Aurelio, Luigi 
%T Synthesis and Structural Characterization of <emph type="2">N</emph>-Methyl-DL-glutamic Acid
%J Australian Journal of Chemistry
%D 2000/06/26
%V 53
%N 3
%P 237-240
%K X-Ray crystallography; zwitterion; glutamic acid; peptide.
%R https://doi.org/10.1071/CH99182
%U https://www.publish.csiro.au/paper/CH99182 
%X The solid-state conformation of racemic N-methylglutamic acid has been defined by single-crystal X-ray crystallography. Orthorhombic crystals belong to the space group Pbca with a 15.219(2), b 10.583(1), c 9.595(1) &#197; and Z 8. The structure was refined to a final R value of 0.049 for the 1285 measured data. In the crystal the molecules adopt a zwitterionic form with protonation having occurred at the amino nitrogen atom. The a-carboxyl is unprotonated with the d-carboxy group retaining a proton. The i.r. spectrum shows absorptions which also are indicative of the amino acid being in the zwitterionic form. Intermolecular H-bonds involving the carboxylate proton and the two protons on the N-atom link the molecules into a three-dimensional network in the crystal. 
