Crystal structure of 2,6-bis(2-hydroxy-5-methylphenyl)-4-phenylpyridinium bromide dichloromethane hemisolvate hemihydrate

Abstract

The asymmetric unit in the structure of the title compound, C25H22NO2+·Br −·0.5CH2Cl2·0.5H2O, comprises two pseudosymmetry-related cations, two bromide anions, a dichloromethane molecule and a water molecule of solvation. The two independent cations are conformationally similar with the comparative dihedral angles between the central pyridine ring and the three benzene substituent rings being 3.0 (2), 36.4 (1) and 24.2 (1)°, and 3.7 (2), 36.5 (1) and 24.8 (1)°, respectively. In the crystal, the cations, anions and water molecules are linked through O—H...O and O—H...Br hydrogen bonds, forming an insular unit. Within the cations there are also intramolecular N—H...O hydrogen bonds. Adjacent centrosymmetrically related aggregates are linked by π–π stacking interactions between the pyridine ring and a benzene ring in both cations [ring-centroid separations = 3.525 (3) and 3.668 (3) Å], forming chains extending across the ac diagonal. Voids between these chains are filled by dichloromethane molecules.

Keywords

• crystal structure
• ONO-type ligands
• pseudosymmetry
• hydrogen bonding
• π–π stacking