Crystal structure and Hirshfeld surface analysis of a pyridiniminium bromide salt: 1-[2-([1,1 '-biphenyl]-4-yl)-2-oxoethyl]-3-methyl-1,4-dihydropyridin-4-iminium bromide

In the cation of the title salt, C20H19N2O+center dot Br-, the phenyl rings are inclined to one another by 38.38 (8)degrees, whereas the central phenyl ring and the pyridiniminium ring are almost perpendicular with a dihedral angle of 87.37 (9)degrees. The N+=C cationic double bond was verified by the shortened bond length of 1.337 (2)degrees. In the crystal, the Br- anion is linked to the cation by an N-H center dot center dot center dot Br hydrogen bond. C-H center dot center dot center dot O hydrogen bonds link adjacent pyridiniminium cations into inversion dimers with an R-2(2) (18) graph-set motif. These dimers are stacked in a phenyl-phenyl T-shaped geometry through C-H center dot center dot center dot pi interactions. A Hirshfeld surface analysis was conducted to verify the contributions of the different intermolecular interactions.