4-(4-Amino­phenyl­sulfon­yl)anilinium toluene-4-sulfonate

In the title p-toluene­sulfonate salt of the drug dapsone, C₁₂H₁₃N₂O₂S⁺·C₇H₇O₃S⁻, the dihedral angle between the two aromatic rings of the dapsone monocation is 70.19 (17)° and those between these rings and that of the p-toluene­sulfonate anion are 72.34 (17) and 46.43 (17)°. All amine and aminium H atoms are involved in inter­molecular N—H...O hydrogen-bonding associations with sulfonyl O-atom acceptors as well as one of the sulfone O atoms, giving a three-dimensional structure.

Crystal structures and hydrogen bonding in the proton-transfer salts of nicotine with 3,5-di­nitro­salicylic acid and 5-sulfosalicylic acid

The crystal structures of the 1:1 salts of nicotine with 3,5-di­nitro­salicylic acid and with 5-sulfosalicylic acid both show polymeric hydrogen-bonded and π–π-bonded structures but these differ in that in the first example, cations and anions form separate cation chains or anion columns which are unassociated through formal hydrogen bonds while in the second, hydrogen-bonded cation–anion chains are found.