(E)-2-[(2,4,6-Tri­meth­oxy­benzyl­idene)amino]­phenol

There are two independent mol­ecules in the asymmetric unit of the title compound, C₁₆H₁₇NO₄, with similar conformations but some differences in their bond angles. Each mol­ecule adopts a trans configuration with respect to the methyl­idene C=N bond and is twisted with a dihedral angle between the two substituted benzene rings of 80.52 (7)° in one mol­ecule and 83.53 (7)° in the other. All meth­oxy groups are approximately coplanar with the attached benzene rings, with C_meth­yl—O—C—C torsion angles ranging from −6.7 (2) to 5.07 (19)°. In the crystal, independent mol­ecules are linked together by O—H...N and O—H...O hydrogen bonds and a π–π inter­action [centroid–centroid distance of 3.6030 (9) Å], forming a dimer. The dimers are further linked by weak C—H...O inter­actions and another π–π inter­action [centroid–centroid distance of 3.9452 (9) Å] into layers lying parallel to the ab plane.

(E)-2-[4-(Di­ethyl­amino)­styr­yl]-1-methyl­quinolin-1-ium 4-chloro­benzene­sulfonate monohydrate

The asymmetric unit of the title hydrated salt, C₂₂H₂₅N₂⁺·C₆H₄ClO₃S⁻·H₂O, comprises two 2-[4-(di­ethyl­amino)­styr­yl]-1-methyl­quinolin-1-ium cations, two 4-chloro­benzene­sul­fon­ate anions and two solvent water mol­ecules. One ethyl group of both cations displays disorder over two positions in a 0.659 (2):0.341 (2) ratio in one mol­ecule and in a 0.501 (2):0.499 (2) ratio in the other. The sulfonate group of one anion is also disordered over two positions in a 0.893 (7):0.107 (7) ratio. The dihedral angle between the mean plane of the quinolinium ring system and that of benzene ring is 10.57 (18)° in one cation and 14.4 (2)° in the other. In the crystal, cations, anions and water mol­ecules are linked into chains along the [010] direction by O—H...O_sulfonate hydrogen bonds, together with weak C—H...O_sulfonate and C—H...Cl inter­actions. The cations are stacked by π–π inter­actions, with centroid–centroid distances in the range 3.675 (2)–4.162 (3) Å.