title: 2-Amino-5-chloro-pyrimidin-1-ium hydrogen maleate.
abstract: In the title salt, C(4)H(5)ClN(3) (+)·C(4)H(3)O(4) (-), the 2-amino-5-chloro-pyrimidinium 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 intra-molecular O-H⋯O 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 carboxyl-ate O atoms of the anion via a pair of N-H⋯O hydrogen bonds, forming an R(2) (2)(8) ring motif. The ion pairs are connected via further N-H⋯O hydrogen bonds and a short C-H⋯O inter-action, forming layers lying parallel to the bc plane.
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun
authors.forename: Madhukar
authors.initials: M
authors.lastname: Hemamalini
authors.forename: Venkatachalam
authors.initials: V
authors.lastname: Rajakannan