title: 1,4-Bis(4-pyridylmeth-yl)piperazin-1-ium perchlorate fumaric acid hemisolvate.
abstract: In the title salt, C(16)H(21)N(4) (+)·ClO(4) (-)·0.5C(4)H(4)O(4), fumaric acid mol-ecules, situated across crystallographic inversion centres, are O-H⋯N hydrogen bonded to two protonated 1,4-bis-(4-pyridylmeth-yl)piperazine cations, forming trimolecular units. These construct one-dimensional supra-molecular ribbons by N-H⋯N hydrogen bonding, and further aggregate via π-π inter-actions [shortest C⋯C contact = 3.640 (1) Å] and perchlorate-mediated C-H⋯O inter-actions.
authors.affiliation: Lyman Briggs College, Department of Chemistry, Michigan State University, East Lansing, MI 48825, USA.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Farnum
authors.forename: Robert L
authors.initials: RL
authors.lastname: Laduca