title: Bis(tetra-methyl-amonium) bis-(2,4,5-carboxy-benzoate)-benzene-1,2,4,5-tetra-carboxylic acid (1/1).
abstract: The asymmetric unit of the title compound, 2C(4)H(12)N(+)·2C(10)H(5)O(8) (-)·C(10)H(6)O(8), consists of a tetra-methyl-amonium cation, an anion derived from the singly deprotonated pyromellitic acid anion, 2,4,5-carboxy-benzoate (H(3)bta(-)), and one-half of a benzene-1,2,4,5-tetra-carboxylic acid (H(4)bta) mol-ecule, which has the centroid of the aromatic ring positioned at a crystallographic centre of inversion. The H(4)bta and H(3)bta(-) residues are involved in an extensive inter-molecular O-H⋯O hydrogen-bonding network, which leads to a three-dimensional supra-molecular structure containing one-dimensional channels running parallel to the [001] crystallographic direction. These channels house the tetra-methyl-amonium cations.
authors.forename: Luís
authors.initials: L
authors.lastname: Cunha-Silva
authors.forename: Penka I
authors.initials: PI
authors.lastname: Girginova
authors.forename: Tito
authors.initials: T
authors.lastname: Trindade
authors.forename: João
authors.initials: J
authors.lastname: Rocha
authors.forename: Jacek
authors.initials: J
authors.lastname: Klinowski
authors.forename: Filipe A
authors.initials: FA
authors.lastname: Almeida Paz