title: Two polymorphs of 2-ethyl-3-hydroxy-6-methylpyridinium hydrogen N-acetyl-L-glutamate from powder diffraction data.
abstract: The title salt, C8H12NO(+)·C7H10NO5(-), crystallizes in two polymorphic modifications, viz. monoclinic (M) and orthorhombic (O). The crystal structures of both polymorphic modifications have been established from laboratory powder diffraction data. The crystal packing motifs in the two polymorphs are different, but the conformations of the anions are generally similar. In M, the anions are linked by pairs of hydrogen bonds of the N-H···O and O-H···O types into chains along the b-axis direction, and neighbouring molecules within the chain are related by the 21 screw axis. The cations link these chains via O-H···O and N-H···O hydrogen bonds into layers parallel to (001). In O, the anions are linked by O-H···O hydrogen bonds into helices along [001], and neighbouring molecules within the helix are related by the 21 screw axis. The neighbouring helical turns are linked by N-H···O hydrogen bonds. The cations link the helices via O-H···O and N-H···O hydrogen bonds, thus forming a three-dimensional network.
authors: Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russian Federation.
authors: Vladimir V
authors: VV
authors: Chernyshev
authors: Sergey Y
authors: SY
authors: Efimov
authors: Ksenia A
authors: KA
authors: Paseshnichenko
authors: Andrey A
authors: AA
authors: Shiryaev
mesh_terms: D003460:Crystallization; D005971:Glutamates / Q000737:chemistry*; D006860:Hydrogen Bonding; D007477:Ions / Q000737:chemistry*; D015394:Molecular Structure; D033362:Powder Diffraction; D012492:Salts / Q000737:chemistry*
chemical_list: C587642:2-ethyl-3-hydroxy-6-methylpyridinium hydrogen N-acetyl-L-glutamate; D005971:Glutamates; D007477:Ions; D012492:Salts
keywords: N-acetyl-l-glutamic acid; antihypoxic activity; crystal structure; hydrogen bonding; polymorphs; powder diffraction