(E)-2-[4-(Dimethyl­amino)­styr­yl]-1-methyl­pyridinium triiodide

The asymmetric unit of the title compound, C16H19N2 +·I3 −, contains a (E)-2-[4-(dimethyl­amino)­styr­yl)-1-methyl­pyrid­in­ium cation and half each of two triiodide anions. The complete triiodide anions are each generated by inversion symmetry. The planar cation has all of its eighteen non-H atoms situated on a mirror plane. In the crystal, the cations are stacked along the b axis by π–π inter­actions with a centroid–centroid distance of 3.5757 (13) Å. The triiodide anions are located between the cations. The crystal structure is further consolidated by short C⋯C [3.322 (9)–3.3952 (19) Å] contacts

2-[(E)-2-(4-Eth­oxy­phen­yl)ethen­yl]-1-methyl­pyridinium 4-chloro­benzene­sulfonate monohydrate1

In the title compound, C16H18NO+·C6H4ClO3S−·H2O, the cation exists in an E configuration with respect to the ethenyl bond and is slightly twisted with a dihedral angle of 9.85 (5)° between the pyridinium and the benzene rings. The anion is inclined to the cation with the dihedral angles between the benzene ring of the anion and the pyridinium and benzene rings of the cation of 78.33 (6) and 68.73 (6)°, respectively. In the crystal, the cations and anions are arranged alternately into head-to-head ribbons along the c axis, with the cationic ribbons stacked along the b axis. The crystal is consolidated by O—H⋯O hydrogen bonds, weak C—H⋯O and C—H⋯π inter­actions. π–π inter­actions with centroid–centroid distances of 3.6111 (7) and 3.6466 (7) Å are also observed

2-[(E)-4-(Dimethyl­amino)­styr­yl]-1-methyl­pyridinium 4-chloro­benzene­sulfonate monohydrate1

In the title hydrated mol­ecular salt, C16H19N2 +·C6H4ClO3S−·H2O, the 2-[4-(dimethyl­amino)­styr­yl]-1-methyl­pyridinium cation exists in an E configuration with respect to the C=C bond and is slightly twisted, with the dihedral angle between the pyridinium and benzene rings being 9.33 (10)°. In the crystal structure, the packing is stabilized by O—H⋯O hydrogen bonds and weak C—H⋯O inter­actions, which link the cations, anions and water mol­ecules into chains propagating in [010]. These chains are stacked along the a axis by π–π inter­actions, with centroid-to-centroid distances of 3.6429 (12) and 3.6879 (12) Å; weak C—H⋯π inter­actions are also observed

2-[(E)-2-(4-Chloro­phen­yl)ethen­yl]-1-methyl­pyridinium 4-methoxy­benzene­sulfonate

In the asymmetric unit of the title salt, C14H13ClN+·C7H7O4S−, there are two crystallographically independent mol­ecules for each component. Each cation adopts an E configuration with respect to the C=C bond and is slightly twisted; the dihedral angle between the pyridinium and benzene rings is 6.53 (7)° for one mol­ecule and 5.30 (7)° for the other. The meth­oxy groups in the anion mol­ecules are each twisted from the mean plane of benzene ring with torsion angles of 16.38 (19) and 4.32 (19)°. In the crystal structure, the cations are stacked in an anti­parallel manner along the a axis and the anions are linked together by C—H⋯O inter­actions into a layer parallel to (001). The anion layers are further linked to adjacent cations by C—H⋯O inter­actions. C—H⋯π inter­actions involving the benzene rings of both ions are also observed

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

In the title compound, C18H23N2 +·I−, the cation exists in the E configuration with respect to the ethenyl C=C bond. The pyridinium and benzene rings are nearly coplanar, making a dihedral angle of 4.63 (7)°. The two ethyl groups of the diethyl­amino substituent point in opposite directions with respect to the benzene plane. In the crystal, the cation and the iodide anion are linked by a weak C—H⋯I inter­action. The cations are stacked in an anti-parallel manner along the a axis by a π–π inter­action with a centroid–centroid distance of 3.5262 (9) Å. The crystal structure is further stabilized by C—H⋯π inter­actions

1,1′-Dimethyl-4,4′-[(2,4-diphenyl­cyclo­butane-1,3-di­yl)dipyridinium–(E)-1-methyl-4-styrylpyridinium–benzene­sulfonate (0.15/1.70/2)

In the title compound, 1.70C14H14N+·0.15C28H28N2 2+·2C6H5O3S−, the monocation exists in the E configuration with respect to the ethenyl C=C double bond and is close to planar, the dihedral angle between the pyridinium and phenyl ring being 5.20 (13)°. The dication lies about an inversion centre. In the crystal, the dication occupies almost the same site occupied by monocations at (x, y, z) and (2 − x, 1 − y, 1 − z). The O atoms of the anion are disordered over two positions with occupancies of 0.75 and 0.25. In the crystal, the cations are stacked in an anti­parallel manner along the a axis, whereas the anions are linked into chains along the same direction by C—H⋯O hydrogen bonds. In addition, C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.593 (9) or 3.6705 (16) Å] are observed

2,2′-[2,4-Bis(naphthalen-1-yl)cyclo­butane-1,3-di­yl]bis­(1-methyl­pyridinium) diiodide: thermal-induced [2 + 2] cyclo­addition reaction of a heterostilbene1

The asymmetric unit of the title compound, C36H32N2 2+·2I−, consists of one half-mol­ecule of the cation and one I− anion. The cation is located on an inversion centre. The dihedral angle between the pyridinium ring and the naphthalene ring system in the asymmetric unit is 19.01 (14)°. In the crystal, the cations and the anions are linked by C—H⋯I inter­actions into a layer parallel to the bc plane. Intra- and inter­molecular π–π inter­actions with centroid–centroid distances of 3.533 (2)–3.807 (2) Å are also observed

2-[(E)-2-(4-Ethoxy­phen­yl)ethen­yl]-1-methyl­pyridinium 4-bromo­benzene­sulfonate monohydrate1

In the title compound, C16H18NO+·C6H4BrO3S−·H2O, the cation exists in an E configuration with respect to the ethenyl bond and is slightly twisted with a dihedral angle of 8.5 (2)° between pyridinium and benzene rings. In the crystal, the cations are arranged in layers parallel to (100), with π–π inter­actions between pyridinium and benzene rings [centroid–centroid distances = 3.651 (3) and 3.613 (3) Å]. The anions and water mol­ecules are located between the cationic layers. The ions and water mol­ecules are linked into a three-dimensional framework by O—H⋯O and C—H⋯O hydrogen bonds

(E)-1-Methyl-2-styrylpyridinium iodide

In the title compound, C14H14N+·I−, the cation exists in an E configuration with respect to the ethenyl bond and is slightly twisted, the inter­planar angle between the pyridinium and phenyl rings of the cation being 4.8 (2)°. In the crystal packing, the cations are stacked in an anti­parallel fashion along the a axis by a π–π inter­action involving both pyridinium and phenyl rings; the centroid–centroid distance is 3.542 (3) Å. Each iodide ion is sandwiched between two cations. The cations and iodide anions are linked together by weak C—H⋯I inter­actions, giving rise to ladder-like ribbons along the a axis