Characterization of molecular associations involving L-ornithine and α-ketoglutaric acid: crystal structure of L-ornithinium α-ketoglutarate

Abstract

The crystal structure of L-ornithinium α-ketoglutarate (C5H13N2O2, C5H5O5) has been solved by direct methods using single crystal X-ray diffraction data. It crystallizes in the monoclinic system, space group P21, unit cell parameters a=15.4326(3), b=5.2015(1), c=16.2067(3) Å and β=91.986(1)°, containing two independent pairs of molecular ions in the asymmetric unit. An extensive hydrogen-bond network and electrostatic charges due to proton transfer provide an important part of the cohesive energy of the crystal. The conformational versatility of L-ornithine and α-ketoglutaric acid is illustrated by the present results and crystal structures available from the Cambridge Structural Database.

Keywords: Conformation de la l-ornithine; Conformation de l’acide α-cétoglutarique; Crystal structure; Structure cristalline; Zwitterion; l-ornithine conformation; l-ornithinium α-ketoglutarate; α-cétoglutarate de l-ornithinium; α-ketoglutaric acid conformation.