Synthesis and absolute structure of (R)-2-(benzyl­selan­yl)-1-phenyl­ethanaminium hydrogen sulfate monohydrate: crystal structure and Hirshfeld surface analyses

A hydrogen sulfate salt, C(15)H(18)NSe(+)·HSO(4) (−)·H(2)O or [BnSeCH(2)CH(Ph)NH(3) (+)](HSO(4) (−)), of a chiral selenated amine (R)-2-(benzyl­selan­yl)-1-phenyl­ethan­amine (BnSeCH(2)CH(Ph)NH(2)) has been synthesized and characterized by elemental analysis,(1)H and (13)C{(1)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 P2(1) 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 nitro­gen atom is chiral and in the R configuration, and, the –C—C– bond of the –CH(2)—CH– fragment has a staggered conformation. In the crystal structure, two HSO(4) (−) anions and two water mol­ecules form an R (4) (4)(12) tetra­meric type of assembly comprised of alternating HSO(4) (−) anions and water mol­ecules via discrete D(2) O—H⋯O hydrogen bonds. This tetra­meric assembly aggregates along the b-axis direction as an infinite one-dimensional tape. Adjacent tapes are inter­connected via discrete D(2) N—H⋯O hydrogen bonds between the three amino hydrogen atoms of the cation sandwiched between the two tapes and the three HSO(4) (−) anions of the nearest asymmetric units, resulting in a complex two-dimensional sheet along the ab plane. The pendant arrangement of the cations is stabilized by C—H⋯π inter­actions between adjacent cations running as chains down the [010] axis. Secondary Se⋯O [3.1474 (4) Å] inter­actions are also observed in the crystal structure. A Hirshfeld surface analysis, including d (norm), shape-index and fingerprint plots of the cation, anion and solvent mol­ecule, was carried out to confirm the presence of various inter­actions in the crystal structure.