Crystal and molecular structure of glycyl-L-ieucine

Abstract

The crystal structure of the title compound has been determined by direct methods from diffractometer data. Crystals are monoclinic, with Z= 2 in a unit cell of dimensions: a= 6·369(5), b= 5·565(5), c= 15·350(10)Å, β= 102·77(4)°, space group P2₁. The structure was refined by least-squares to R 0·044 for 823 observed reflections. The four protons available for hydrogen-bond formation are a three-dimensional network which stabilizes the structure. There is significant non-planarity of the peptide linkage, the torsion angle about the peptide bond being –11·4°. The nitrogen atom of the peptide group is significantly pyramidal. The molecular conformation is discussed.