4-{[4-(Di­methyl­amino)­benzyl­idene]amino}­benzene­sulfonamide

The title Schiff base compound, C₁₅H₁₇N₃O₂S, is non-planar with a dihedral angle of 69.88 (4)° between the planes of the benzene rings. In the crystal, pairs of N—H...N hydrogen bonds, between the sulfonamide nitro­gen-H atom and the azomethine N atom, link the mol­ecules into inversion dimers, forming R₂²(16) ring motifs. These dimers are linked by N—H...O hydrogen bonds, between the sulfonamide nitro­gen-H atom and one sulfonamide O atom, forming sheets lying parallel to (100). Within the sheets there are weak parallel slipped π–π inter­actions involving inversion-related benzene­sulfonamide rings [centroid–centroid distance = 3.8800 (9) Å; normal distance = 3.4796 (6) Å; slippage = 1.717 Å].

Crystal structure of 4,4′-bipyridine-1,1'-diium naphthalene-2,6-di­sulfonate dihydrate

The title hydrated mol­ecular organic salt, C₁₀H₁₀N₂²⁺·C₁₀H₆O₆S₂²⁻·2H₂O, crystallized with half a bipyridinium cation, half a naphthalene-2,6-di­sulfonate anion and a water mol­ecule in the asymmetric unit. The whole cation and anion are generated by inversion symmetry, the inversion centers being at the center of the bridging C—C bond of the cation, and at the center of the fused C—C bond of the naphthalene group of the anion. In the crystal, the anions and cations stack alternately along the a axis with π–π inter­actions [inter-centroid distance = 3.491 (1) Å]. The anions are linked via O—H...O(sulfonate) hydrogen bonds involving two inversion-related water mol­ecules, forming chains along [10-1]. These chains are bridged by bifurcated N—H...(O,O) hydrogen bonds, forming a three-dimensional framework structure. There are also C—H...O hydrogen bonds present, reinforcing the framework structure.