title: Tetra-methyl-ammonium hydrogen terephthalate.
abstract: The asymmetric unit of the title salt, C(4)H(12)N(+)·C(8)H(5)O(4) (-), contains one half of a tetra-methyl-ammonium cation and one half of a hydrogen terephthalate monoanion. The N atom of the ammonium cation lies on a twofold rotation axis and the centre of mass of the terephthalate anion is on a centre of inversion. In the crystal, the centrosymmetric terephthalate ions are linked by a very short symmetric O-H⋯O hydrogen bond [O⋯O = 2.4610 (19) Å] into a one-dimensional polymeric chain along [1-12]. The tetra-methyl-ammonium cations and terephthalate anions are then connected through a pair of bifurcated acceptor C-H⋯O hydrogen bonds, generating a three-dimensional supra-molecular network. The carboxyl-ate groups at both ends of the terephthalate anion are charge-shared with an equal probability of 0.5.
authors.affiliation: Department of Chemistry, Zanjan Branch, Islamic Azad University, PO Box 49195-467, Zanjan,  Iran.
authors.forename: Leila
authors.initials: L
authors.lastname: Dolatyari
authors.forename: Samad
authors.initials: S
authors.lastname: Shoghpour Bayraq
authors.forename: Sara
authors.initials: S
authors.lastname: Sharifi
authors.forename: Ali
authors.initials: A
authors.lastname: Ramazani
authors.forename: Ali
authors.initials: A
authors.lastname: Morsali
authors.forename: Hadi
authors.initials: H
authors.lastname: Amiri Rudbari