Strong asymmetric hydrogen bonding in 2-(oxamoylamino)ethylammonium oxamate-oxamic acid (1/1)

Martinez Belmonte, M. and Price, D.J. (2010) Strong asymmetric hydrogen bonding in 2-(oxamoylamino)ethylammonium oxamate-oxamic acid (1/1). Acta Crystallographica. Section C: Crystal Structure Communications, 66(3), o147-o150. (doi: 10.1107/S0108270110004233)

Abstract

The title compound, C₄H₁₀N₃O₂+·C₂H₂NO₃-·C₂H₃NO₃, contains at least 11 distinct hydrogen-bond interactions showing a great variety of bond strengths. The shortest and strongest hydrogen bond [O...O = 2.5004 (12) Å] is found between the uncharged oxamic acid molecule and the oxamate monoanion. The grouping formed by such a strong hydrogen bond can thus be considered as a hydrogen bis(oxamate) monoanion. It lacks crystallographic symmetry and the two oxamate groups have different conformations, showing an asymmetric hydrogen-bond interaction. Significantly, the asymmetry allows us to draw a direct comparison of site basicity for the two inequivalent carboxylate O atoms in the planar oxamate anion. The constituent molecular ions of (I) form ribbons, where all amide and carboxylate groups are coplanar. Graph-set analysis of the hydrogen-bonded networks reveals the R²2(10) and R²2(9) homodromic nets as important structure-directing motifs, which appear to be a common feature of many oxamate-containing compounds.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Price, Dr Daniel
• Authors: Martinez Belmonte, M., and Price, D.J.
• Subjects: Q Science > QD Chemistry
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Acta Crystallographica. Section C: Crystal Structure Communications
• Publisher: International Union of Crystallography
• ISSN: 0108-2701
• ISSN (Online): 1600-5759
• Copyright Holders: Copyright © 2010 International Union of Crystallography
• First Published: First published in Acta Crystallographica. Section C: Crystal Structure Communications 66(3):o147-o150
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher