Synthesis, crystal structure and Hirshfeld surface analysis of 3-(4-fluoro-phen-yl)-2-formyl-7-methyl-imidazo[1,2- a]pyridin-1-ium chloride monohydrate

Abstract

In the title salt, C₁₅H₁₂FN₂O⁺·Cl^-·H₂O, the imidazo[1,2-a]pyridin-1-ium ring system of the cation is almostly planar [maximum deviaition = -0.047 (2) Å for the ring C atom with the attached arene ring] and forms a dihedral angle of 61.81 (6)° with the plane of the fluoro-phenyl ring. In the crystal, water mol-ecules form an R ₂ ⁴(8) motif parallel to the (100) plane by bonding with the chloride ions via O-H⋯Cl hydrogen bonds. The cations are connected along the b axis via N-H⋯O hydrogen bonds involving the O atoms of water mol-ecules, and C-H⋯O, C-H⋯Cl and π-π inter-actions [centroid-to-centroid distance = 3.6195 (8) Å] form layers parallel to the (100) plane. Furthermore, these layers are connected via π-π inter-actions [centroid-to-centroid distance = 3.8051 (9) Å] that further consolidate the crystal structure.

Keywords: Hirshfeld surface analysis; crystal structure; hydrogen bonds; imidazo[1,2-a]pyridin-1-ium; π–π inter­actions.