Received 30 November 2011
In the title salt, C4H5ClN3+·C4H3O4-, the 2-amino-5-chloropyrimidinium cation is protonated at one of its pyrimidine N atoms. In the roughly planar (r.m.s. deviation = 0.026 Å) hydrogen malate anion, an intramolecular O-HO hydrogen bond generates an S(7) ring. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms of the anion via a pair of N-HO hydrogen bonds, forming an R22(8) ring motif. The ion pairs are connected via further N-HO hydrogen bonds and a short C-HO interaction, forming layers lying parallel to the bc plane.
For background to pyrimidine compounds, see: Glidewell et al. (2003); Panneerselvam et al. (2004). For details of maleic acid, see: James & Williams (1974); Bertolasi et al. (1980). For hydrogen-bond motifs, see: Bernstein et al. (1995).
Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB6543 ).
HKF and MH thank the Malaysian Government and Universiti Sains Malaysia for the Research University grant No. 1001/PFIZIK/811160. MH also thanks Universiti Sains Malaysia for a post-doctoral research fellowship.
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