These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: L-cysteinium semioxalate.
    Author: Minkov VS, Boldyreva EV.
    Journal: Acta Crystallogr C; 2008 Jun; 64(Pt 6):o344-8. PubMed ID: 18535345.
    Abstract:
    The title salt, C3H8NO2+.C2HO4-, formed between L-cysteine and oxalic acid, was studied as part of a comparison of the structures and properties of pure amino acids and their cocrystals. The structure of the title salt is very different from that formed by oxalic acid and equivalent amounts of D- and L-cysteine molecules. The asymmetric unit contains an L-cysteinium cation and a semioxalate anion. The oxalate anion is only singly deprotonated, in contrast with the double deprotonation in the crystal structure of bis(DL-cysteinium) oxalate. The oxalate anion is not planar. The conformation of the L-cysteinium cation differs from that of the neutral cysteine zwitterion in the monoclinic and orthorhombic polymorphs of L-cysteine, but is similar to that of the cysteinium cation in bis(DL-cysteinium) oxalate. The structure of the title salt can be described as a three-dimensional framework formed by ions linked by strong O-H...O and N-H...O and weak S-H...O hydrogen bonds, with channels running along the crystallographic a axis containing the bulky -CH2SH side chains of the cysteinium cations. The cations are only linked through hydrogen bonds via semioxalate anions. There are no direct cation-cation interactions via N-H...O hydrogen bonds between the ammonium and carboxylate groups, or via weaker S-H...S or S-H...O hydrogen bonds.
    [Abstract] [Full Text] [Related] [New Search]