title: Desipramine hydro-chloride: a non-merohedrally twinned structure.
abstract: The title compound, C(18)H(23)N(2) (+)·Cl(-), is a non-merohedrally twinned salt [domains 0.9288 (3) and 0.0712 (3)] which crystallizes with four independent cation-anion pairs in the asymmetric unit. The seven-membered ring in each of the cations adopts a boat conformation, thus creating a butterfly effect within the ring system. The average value of the dihedral angle between the two aromatic rings in the four cations is 57.1 (1)°. The crystal packing is stabilized only slightly by a collection of inter-mediate N-H⋯Cl hydrogen-bonding inter-actions, which produce a weak, but cooperative, infinite, one-dimensional, inter-molecular hydrogen-bond network along the a axis. A MOPAC PM3 computational calculation gives support to these observations.
authors.forename: Jerry P
authors.initials: JP
authors.lastname: Jasinski
authors.forename: Ray J
authors.initials: RJ
authors.lastname: Butcher
authors.forename: Q N M
authors.initials: QN
authors.lastname: Hakim Al-Arique
authors.forename: H S
authors.initials: HS
authors.lastname: Yathirajan
authors.forename: A R
authors.initials: AR
authors.lastname: Ramesha