title: 4-Chloro-anilinium 3-carb-oxy-prop-2-enoate.
abstract: In the title compound, C(6)H(7)ClN(+)·C(4)H(3)O(4) (-), the cations and anions lie on mirror planes and hence only half of the mol-ecules are present in the asymmeric unit. The 4-chloro-anilinium cation and hydrogen maleate anion in the asymmetric unit are each planar and are oriented at an angle of 15.6 (1)° to one another and perpendicular to the b axis. A characterestic intra-molecular O-H⋯O hydrogen bond, forming an S(7) motif, is observed in the maleate anion. In the crystal, the cations and anions are linked by N-H⋯O hydrogen bonds, forming layers in the ab plane. The aromatic rings of the cations are sandwiched between hydrogen-bonded chains and rings formed through the amine group of the cation and maleate anions, leading to alternate hydro-phobic (z = 0 or 1) and hydro-philic layers (z = 1/2) along the c axis.
authors.forename: R
authors.initials: R
authors.lastname: Anitha
authors.forename: S
authors.initials: S
authors.lastname: Athimoolam
authors.forename: S Asath
authors.initials: SA
authors.lastname: Bahadur
authors.forename: M
authors.initials: M
authors.lastname: Gunasekaran