title: trans-2,5-Di-methyl-piperazine-1,4-diium bis(perchlorate) dihydrate: crystal structure and Hirshfeld surface analysis.
abstract: The asymmetric unit of the title hydrated mol-ecular salt, C6H16N2 (2+)·2ClO4 (-)·2H2O, contains a half dication (completed by inversion symmetry), a perchlorate anion and a water mol-ecule. The extended structure consists of infinite chains of formula [(ClO4)H2O] n (n) (-) ions extending along the b axis linked by Ow-H⋯O (w = water) hydrogen bonds. These chains are cross-linked by the dications via N-H⋯Ow and weak C-H⋯O hydrogen bonds, thus forming a three-dimensional supra-molecular network. Three-dimensional Hirshfeld surface analysis and two-dimensional fingerprint maps reveal that the structure is dominated by H⋯O/O⋯H and H⋯H contacts.
authors.affiliation: Laboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna Bizerte, Université de Carthage, Tunisia.
authors.forename: Cherifa
authors.initials: C
authors.lastname: Ben Mleh
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 de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna Bizerte, Université de Carthage, Tunisia.
authors.forename: Houda
authors.initials: H
authors.lastname: Marouani
keywords: Hirshfeld surface analysis; crystal structure; hydrogen bonding; mol­ecular salt; piperazine derivative