5-Amino-3-eth­oxy-1,8,8-trimethyl-2-aza­bicyclo­[2.2.2]octa-2,5-diene-4,6-dicarbo­nitrile

The title 2-aza­bicyclo­[2.2.2]octa-2,5-diene derivative, C₁₄H₁₈N₄O, crystallized out with two independent mol­ecules with similar conformations in the asymmetric unit. In each mol­ecule, the three six-membered rings adopt boat conformations. The mol­ecules exist in the enamine form. In the crystal, mol­ecules are linked by N—H...O and N—H...N hydrogen bonds into a two-dimensional network parallel to the ab plane.

(E)-1-(2,4-Dinitro­phen­yl)-2-[1-(3-nitro­phen­yl)ethyl­idene]hydrazine

In the asymmetric unit of the title compound, C₁₄H₁₁N₅O₆, there are three crystallographically independent mol­ecules with similar conformations but some differences in bond angles. The mol­ecules are slightly twisted with the dihedral angles between the benzene rings being 10.02 (14), 8.41 (15) and 1.40 (14)°. In each mol­ecule, an intra­molecular N—H...O hydrogen bond generates an S(6) ring motif. In the crystal, mol­ecules are linked by weak C—H...O inter­actions into a three-dimensional network. π–π inter­actions with centroid–centroid distances of 3.5635 (17)–3.8273 (18) Å are observed.

(E)-2-[4-(Diethyl­amino)­styr­yl]-1-methyl­pyridinium 4-meth­oxy­benzene­sulfonate monohydrate

In the cation of the title compound, C₁₈H₂₃N₂⁺·C₇H₇O₄S⁻·H₂O, one ethyl group of the diethyl­amino unit is disordered over two sets of sites in a 0.665 (6):0.335 (6) ratio. The styrylpyridinium unit is nearly planar, with a dihedral angle between the pyridinium and benzene rings of 4.27 (8)°. In the crystal, the anion ring is almost perpendicular to the aromatic rings of the cation; the sulfonate-substituted benzene ring forms dihedral angles of 89.60 (8) and 89.37 (8)°, respectively, with the pyridinium and benzene rings of the cation. In the crystal, the three components are linked into a three-dimensional network by O—H...O and C—H...O hydrogen bonds. π–π inter­actions with centroid–centroid distances of 3.6999 (9) and 3.7106 (9) Å are also present.