title: Bis(4-amino-pyridinium) dichromate(VI).
abstract: The asymmetric unit of the title salt, (C5H7N2)2[Cr2O7], contains four independent cations and two independent dichromate anions. The crystal structure consists of discrete dichromate anions with an eclipsed conformation stacked in layers parallel to (010) at y = 1/4 and y = 3/4. These layers are linked via 4-amino-pyridinium cations by N-H⋯O and weak C-H⋯O hydrogen bonds, forming a three-dimensional supra-molecular network. In addition, π-π inter-actions are present in this structure; the shortest distance separating mean planes through 4-amino-pyridinium cations is 3.679 (6) Å.
authors.affiliation: Laboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna Bizerte, Tunisia.
authors.forename: Sonia
authors.initials: S
authors.lastname: Trabelsi
authors.affiliation: Centre de Diffractométrie X, UMR 6226 CNRS, Unité Sciences Chimiques de Rennes, Université de Rennes I, 263 Avenue du Général Leclerc, 35042 Rennes, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Roisnel
authors.affiliation: Laboratoire des Matériaux Utiles, Institut National de Recherche et d'Analyse Physico-chimique, Pole Technologique de Sidi-Thabet, 2020 Tunis, Tunisia.
authors.forename: Hassouna
authors.initials: H
authors.lastname: Dhaouadi
authors.affiliation: Laboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna Bizerte, Tunisia.
authors.forename: Houda
authors.initials: H
authors.lastname: Marouani