Synthesis and absolute structure of ()-2-(benzyl-selan-yl)-1-phenyl-ethanaminium hydrogen sulfate monohydrate: crystal structure and Hirshfeld surface analyses.

A hydrogen sulfate salt, CHNSe·HSO ·HO or BnSeCHCH(Ph)NH , of a chiral selenated amine ()-2-(benzyl-selan-yl)-1-phenyl-ethan-amine (BnSeCHCH(Ph)NH) has been synthesized and characterized by elemental analysis,H and C{H} NMR, FT-IR analysis, and single-crystal X-ray diffraction studies. The title salt crystallizes in the monohydrate form in the non-centrosymmetric monoclinic 2 space group. The cation is somewhat W shaped with the dihedral angle between the two aromatic rings being 60.9 (4)°. The carbon atom attached to the amine nitro-gen atom is chiral and in the configuration, and, the -C-C- bond of the -CH-CH- fragment has a staggered conformation. In the crystal structure, two HSO anions and two water mol-ecules form an (12) tetra-meric type of assembly comprised of alternating HSO anions and water mol-ecules discrete (2) O-H⋯O hydrogen bonds. This tetra-meric assembly aggregates along the axis direction as an infinite one-dimensional tape. Adjacent tapes are inter-connected discrete (2) N-H⋯O hydrogen bonds between the three amino hydrogen atoms of the cation sandwiched between the two tapes and the three HSO anions of the nearest asymmetric units, resulting in a complex two-dimensional sheet along the plane. The pendant arrangement of the cations is stabilized by C-H⋯π inter-actions between adjacent cations running as chains down the [010] axis. Secondary Se⋯O [3.1474 (4) Å] inter-actions are also observed in the crystal structure. A Hirshfeld surface analysis, including , shape-index and fingerprint plots of the cation, anion and solvent mol-ecule, was carried out to confirm the presence of various inter-actions in the crystal structure.