title: 2-Aminopyridinium-fumarate-fumaric acid (2/1/1).
abstract: The title complex, 2C5H7N2+.C4H2O42-.C4H4O4, contains cyclic eight-membered hydrogen-bonded rings involving 2-aminopyridinium and fumarate ions. The fumaric acid molecules and fumarate ions lie on inversion centers and are linked into zigzag chains by O-H...O hydrogen bonds. The dihedral angle between the pyridinium ring and the hydrogen-bonded fumarate ion is 7.60 (4) degrees. The fumarate anion is linked to the pyridinium cations by intermolecular N-H...O hydrogen bonds. The heterocycle is fully protonated, thus enabling amine-imine tautomerization.
authors.affiliation: Department of Physics, Ondokuz Mayis University, TR-55139 Samsun, Turkey.
authors.forename: Orhan
authors.initials: O
authors.lastname: Büyükgüngör
authors.forename: Mustafa
authors.initials: M
authors.lastname: Odabaşoğlu
authors.forename: Ciğdem
authors.initials: C
authors.lastname: Albayrak
authors.forename: Peter
authors.initials: P
authors.lastname: Lönnecke