title: rac-Ammonium cis-2-carb-oxy-cyclo-hexane-1-carboxyl-ate.
abstract: In the structure of the title compound, NH(4) (+)·C(8)H(11)O(4) (-), the carboxyl and carboxyl-ate groups of the cation adopt C-C-C-O torsion angles of 174.9 (2) and -145.4 (2)°, respectively, with the alicyclic ring. The ammonium H atoms of the cations give a total of five hydrogen-bonding associations with carboxyl-ate O-atom acceptors of the anion which, together with a carboxyl O-H⋯O(carboxyl-ate) inter-action give sheet structures which lie in the (101) planes.
authors.affiliation: Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
authors.forename: Graham
authors.initials: G
authors.lastname: Smith
authors.forename: Urs D
authors.initials: UD
authors.lastname: Wermuth