Racemic dipeptide glycyl-DL-leucine at 120 K.

The structure of glycyl-DL-leucine, C(8)H(16)N(2)O(3), has been determined at 120 K by single-crystal X-ray diffraction. In addition to three N-H.O-type hydrogen bonds of the positively charged RNH(3)(+) group of the zwitterionic molecule, an intermolecular N-H. O contact exists between the peptide bond and the carboxylate group. Four hydrogen-bond cycles were identified, giving a complex pattern.