PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-1 (1)
 

Clipboard (0)
None

Select a Filter Below

Journals
Authors
Year of Publication
Document Types
1.  Strong asymmetric hydrogen bonding in 2-(oxamoylamino)ethyl­ammonium oxamate–oxamic acid (1/1) 
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 R 2 2(10) and R 2 2(9) homodromic nets as important structure-directing motifs, which appear to be a common feature of many oxamate-containing compounds.
doi:10.1107/S0108270110004233
PMCID: PMC2855574  PMID: 20203413

Results 1-1 (1)