Crystal structures of two stilbazole derivatives: bis­{(E)-4-[4-(di­ethyl­amino)­styr­yl]-1-methyl­pyridin-1-ium} tetra­iodido­cadmium(II) and (E)-4-[4-(di­ethyl­amino)­styr­yl]-1-methyl­pyridin-1-ium 4-meth­oxy­benzene­sulfonate monohydrate

The title mol­ecular salts, (C(18)H(23)N(2))(2)[CdI(4)], (I), and C(18)H(23)N(2) (+)·C(7)H(7)O(4)S(−)·H(2)O, (II), are stilbazole, or 4-styryl­pyridine, derivatives. The cation, (E)-4-[4-(di­ethyl­amino)­styr­yl]-1-methyl­pyridin-1-ium, has a methyl group attached to pyridine ring and a diethyl amine group attached to the benzene ring. The asymmetric unit of salt (I), comprises one cationic mol­ecule and half a CdI(4) dianion. The Cd atom is situated on a twofold rotation axis and has a slightly distorted tetra­hedral coordination sphere. In (II), the anion consists of a 4-meth­oxy­benzene­sulfonate and it crystallizes as a monohydrate. In both salts, the cations adopt an E configuration with respect to the C=C bond and the pyridine and benzene rings are inclined to each other by 10.7 (4)° in (I) and 4.6 (2)° in (II). In the crystals of both salts, the packing is consolidated by offset π–π stacking inter­actions involving the pyridinium and benzene rings, with centroid–centroid distances of 3.627 (4) Å in (I) and 3.614 (3) Å in (II). In the crystal of (II), a pair of 4-meth­oxy­benzene­sulfonate anions are bridged by O(water)—H⋯O(sulfonate) hydrogen bonds, forming loops with an R (2) (4)(8) motif. These four-membered units are then linked to the cations by a number of C—H⋯O hydrogen bonds, forming slabs lying parallel to the ab plane.