N‐(6‐Methylpyridin‐2‐yl)mesitylenesulfonamide and acetic acid – a salt, a cocrystal or both?

In the solid obtained from N‐(6‐methylpyridin‐2‐yl)mesitylenesulfonamide and acetic acid, the constituents interact via two N—H...O hydrogen bonds. The H atom situated in one of these short contacts is disordered over two positions: one of these positions is formally associated with an adduct of the neutral sulfonamide molecule and the neutral acetic acid molecule, and corresponds to a cocrystal, while the alternative site is associated with salt formation between a protonated sulfonamide molecule and deprotonated acetic acid molecule. Site‐occupancy refinements and electron densities from difference Fourier maps suggest a trend with temperature, albeit of limited significance; the cocrystal is more relevant at 100 K, whereas the intensity data collected at room temperature match the description as cocrystal and salt equally well.