1-Methyl-4-[(E)-2-(2-thien­yl)ethen­yl]pyridinium 4-chloro­benzene­sulfonate1

In the title compound, C12H12NS+·C6H4ClO3S−, the cation is almost planar and exists in the E configuration. The cations and anions form alternate layers parallel to the ab plane. Within each layer, both cations and anions form chains directed along the b axis. The mol­ecules are inter­connected by weak C—H⋯O inter­actions into a three-dimensional network. The crystal structure is further stabilized by C—H⋯π inter­actions involving the thio­phene ring. The sulfonate and thio­phene groups are involved in weak intra­molecular C—H⋯O and C—H⋯S inter­actions, respectively. The latter intra­molecular hydrogen bonds produce S(5) ring motifs

(E)-1-Methyl-4-[2-(2-naphth­yl)vin­yl]pyridinium iodide1

In the title compound, C18H16N+·I−, the cation is disordered over two orientations related by a 180° rotation about its long axis with occupancies of 0.554 (7) and 0.446 (7). Both disorder components exist in an E configuration. The dihedral angle between the pyridinium ring and the naphthalene ring system is 4.7 (6)° in the major disorder component and 1.6 (8)° in the minor component. In the crystal structure, centrosymmetrically related cations are stacked along the a axis, with significant π–π inter­actions between the pyridinium ring and the naphthalene ring system [centroid-centroid distance = 3.442 (9) Å]. The iodide ions are located between adjacent columns of cations. The cations are linked to the iodide ions by C—H⋯I inter­actions. Weak C—H⋯π inter­actions involving the methyl group are also observed

2-[(E)-2-(4-Ethoxy­phen­yl)ethen­yl]-1-methyl­pyridinium iodide monohydrate

In the title compound, C16H18NO+·I−·H2O, the cation is essentially planar, with a dihedral angle of 3.13 (16)° between the pyridinium and benzene rings. The mol­ecule adopts an E configuration with respect to the alkene double bond. In the crystal structure, the cations are packed in an anti-­parallel manner through π–π inter­actions between adjacent pyridinium and benzene rings along the a axis, with centroid-to-centroid distances of 3.615 (2) and 3.630 (2) Å. Water mol­ecules bind the iodide ions through O—H⋯I hydrogen bonds into layers. These layers link with the cations through weak C—H⋯O and C—H⋯I inter­actions

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

In the title salt, C14H13ClN+·C6H4ClO3S−, the cation exists in an E configuration with respect to the ethynyl bond and is approximately planar, with a dihedral angle of 3.4 (2)° between the pyridinium and benzene rings. The anion is approximately perpendicular to the cation plane, the benzene ring of the anion making dihedral angles of 89.4 (2) and 89.9 (2)°, respectively, with the pyridinium and benzene rings of the cation. In the crystal structure, the cations are linked into a chain along the c axis by C—H⋯Cl inter­actions. The anions are linked to the adjacent cation chains by C—H⋯O and C—H⋯Cl inter­actions, forming a two-dimensional network parallel to the bc plane. The crystal structure is further stabilized by C—H⋯π inter­actions. A π–π inter­action is also observed between the pyridinium ring and the benzene ring of the cation with a centroid–centroid distance of 3.668 (3) Å

Bis[(E)-2-(3-hydr­oxy-4-methoxy­phen­yl)ethen­yl]-1-methyl­quinolinium tetra­iodidozincate(II) methanol solvate1

In the title compound, (C19H18NO2)2[ZnI4]·CH3OH, each cation is nearly planar and exists in an E configuration, the dihedral angles between the quinolinium systems and the benzene rings being 1.78 (10) and 5.44 (10)° for the two cations. The [ZnI4]2− anion displays a very slightly distorted tetra­hedral geometry. There are intra­molecular O—H⋯O hydrogen bonds between the hydr­oxy and meth­oxy groups in each cation which generate S(5) ring motifs. In the crystal structure, cations are linked together by O—H⋯O hydrogen bonds and weak C—H⋯O inter­actions, whereas the anions are linked to the cations through weak C—H⋯I inter­actions. The asymmetric unit also contains a methanol solvent mol­ecule which is linked to one of the cations by an O—H⋯O hydrogen bond and the anion through an O—H⋯I hydrogen bond. The crystal is further stabilized by C—H⋯π and π–π inter­actions [centroid–centroid distances 3.6054 (15) and 3.6057 (15) Å]

2-[(E)-2-(1H-Indol-3-yl)ethen­yl]-1-methyl­pyridinium 4-chloro­benzene­sulfonate1

In the title compound, C16H15N2 +·C6H4ClO3S−, the cation exists in an E configuration with respect to the central C=C bond and is approximately planar, with a dihedral angle of 2.95 (5)° between the pyridinium and indole rings. The mean plane of the π-conjugated system of the cation and the benzene ring of the anion are inclined to each other at a dihedral angle of 69.65 (4)°. In the crystal packing, the cations are stacked in an anti­parallel manner along the a axis, resulting in a π–π inter­action with a centroid–centroid distance of 3.5889 (7) Å. The anions are linked into a chain along the a axis by weak C—H⋯O inter­actions. The cations are linked with the anions into a three-dimensional network by N—H⋯O hydrogen bonds and weak C—H⋯O inter­actions. There are also short O⋯Cl [3.1272 (10) Å] and C⋯O [3.1432 (14)–3.3753 (14) Å] contacts. The crystal structure is further stabilized by C—H⋯π inter­actions

1-Methyl-2-[(E)-2-(2-thien­yl)ethen­yl]quinolinium 4-bromo­benzene­sulfonate

In the title compound, C16H14NS+·C6H4BrO3S−, the cation exists in an E configuration and is essentially planar, the dihedral angle between the quinolinium and thio­phene rings being 3.45 (9)°. The anion is inclined to the cation with dihedral angles of 75.43 (8) and 72.03 (11)°, respectively between the benzene ring and the quinolinium and thio­phene rings. In the crystal, the cations and anions are arranged individually into separate chains along the c axis. The cation chains are stacked in an anti­parallel manner along the a axis by π⋯π inter­actions with centroid–centroid distances of 3.7257 (13) and 3.7262 (14) Å. Weak C—H⋯O and C—H⋯π inter­actions link the cations and anions into a three-dimensional network. Short Br⋯S [3.7224 (5) Å] and Br⋯O [3.4267 (16) Å] contacts are also observed

Bis{4-[(E)-2-(1H-indol-3-yl)ethen­yl]-1-methyl­pyridinium} 4-fluoro­benzene­sulfonate nitrate 0.25-hydrate1

In the title compound, 2C16H15N2 +·C6H4FO3S−·NO3 −·0.25H2O, the two cations are nearly planar, with dihedral angles of 1.34 (14) and 4.6 (2)°, respectively, between the pyridinium and indole rings. The cations each adopt E configurations with respect to the C=C bonds and are inclined to each other with a dihedral angle of 77.66 (5)°. The ethenyl group of one cation is disordered over two sites with occupancies of 0.685 (12) and 0.315 (12), and the sulfonate group of the 4-fluoro­benzene­sulfonate anion is also disordered with occupancies of 0.535 (10) and 0.465 (10) for the two sets of O atoms. The anion is also inclined to the two cations, with dihedral angles between the mean planes of the benzene ring and the π-conjugated systems of the cations of 24.72 (11) and 79.83 (11)°. In the crystal structure, the cations are stacked in an anti­parallel fashion into columns approximately along the a axis and are further linked through the anions into a three-dimensional network via N—H⋯O and C—H⋯O inter­actions. The water mol­ecule forms O—H⋯O hydrogen bonds to the nitrate anion and C—H⋯π inter­actions are also observed

(E)-1-Methyl-4-[2-(1-naphth­yl)vin­yl]pyridinium 4-chloro­benzene­sulfonate1

In the title compound, C18H16N+·C6H4ClO3S−, the cation exists in an E configuration with respect to the central C=C bond. The naphthalene ring system is slightly bent, the dihedral angle between the two aromatic rings being 3.71 (14)°. The whole cation is twisted, the dihedral angles between the pyridinium and the two aromatic rings of the naphthalene ring system being 47.44 (14) and 50.81 (14)°. The pyridinium ring and the benzene ring of the anion are inclined to each other at a dihedral angle of 68.21 (13)°. In the crystal structure, the cations and anions are arranged alternately with the cations stacked in an anti-parallel manner along the c axis and the anions linked into chains along the same direction. The cations are linked to the anions by weak C—H⋯O inter­actions, forming a three-dimensional network. The crystal structure is further stabilized by C—H⋯π inter­actions and π–π contacts with centroid–centroid distances of 3.6374 (16) and 3.6733 (17) Å. A short Cl⋯O contact [3.108 (2) Å] is also present

2-[(E)-2-(1H-Indol-3-yl)ethen­yl]-1-methyl­pyridinium 4-bromo­benzene­sulfonate1

In the title compound, C16H15N2 +·C6H4BrO3S−, the cation exists in the E configuration and is essentially planar with a dihedral angle of 3.10 (5)° between the pyridinium ring and the indole ring system. The π-conjugated planes of the cation and the anion are inclined to each other at a dihedral angle of 64.32 (4)°. In the crystal structure, the cations are stacked in an anti­parallel manner along the a axis. The anions are linked into a chain along the a axis. The cations and the anions are linked into a three-dimensional network by N—H⋯O and weak C—H⋯O hydrogen bonds. The crystal structure is further stabilized by C—H⋯π inter­actions. A π–π inter­action between the five-membered heterocyclic ring of the indole system and the pyridinium ring is also observed with a centroid–centroid distance of 3.5855 (7) Å