title: 5,12-Dimethyl-pyrazino-[1,2-a:4,5-a']dibenzimidazole-5,12-diium dichloride dihydrate.
abstract: The title hydrated salt, C18H18N4(2+)·2Cl(-)·2H2O, sits about an inversion centre, such that the asymmetric unit contains one half-mol-ecule. In the crystal, hydrogen bonds occur between the water mol-ecules and chloride anions, and there is π-π stacking of the benzene and imidazole rings of inversion-related pairs of mol-ecules, with a centroid-centroid distance of 3.704 (17) Å.
authors.affiliation: Research Institute of Shaanxi Yanchang Petroleum (Group) Co. Ltd, Ke Ji No. 2 Road 75, Xi'an 710075, Shaanxi, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Han
authors.forename: Ming-Gao
authors.initials: MG
authors.lastname: Zhao
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Lan
authors.initials: L
authors.lastname: Ma
authors.forename: Guang
authors.initials: G
authors.lastname: Fan