title: rac-2-Amino-pyridinium cis-2-carb-oxy-cyclo-hexane-1-carboxyl-ate.
abstract: In the structure of the title compound, C(5)H(7)N(2) (+)·C(8)H(11)O(4) (-), the cis anions associate through head-to-tail carb-oxy-lic acid-carboxyl O-H⋯O hydrogen bonds [graph set C(7)], forming chains which extend along c and are inter-linked through the carboxyl groups, forming cyclic R(2) (2)(8) associations with the pyridinium and an amine H-atom donor of the cation. Further amine-carboxyl N-H⋯O inter-actions form enlarged centrosymmetric rings [graph set R(4) (4)(18)] and extensions down b, giving a three-dimensional structure.
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
references.citation: Acta Crystallogr A. 2008 Jan;64(Pt 1):112-22
references.pmid: 18156677
references.citation: Acta Crystallogr D Biol Crystallogr. 2009 Feb;65(Pt 2):148-55
references.pmid: 19171970
references.citation: Acta Crystallogr Sect E Struct Rep Online. 2010 Dec 18;67(Pt 1):o174
references.pmid: 21522680
references.citation: Acta Crystallogr B. 1990 Apr 1;46 ( Pt 2):256-62
references.pmid: 2344397