Crystal structure determination of two pyridine derivatives: 4-[(E)-2-(4-meth­oxy­phen­yl)ethen­yl]-1-methyl­pyridin-1-ium hexa­fluoro-λ(6)-phosphane and 4-{(E)-2-[4-(di­methyl­amino)­phen­yl]ethen­yl}-1-phenyl-1λ(5)-pyridin-1-ylium hexa­fluoro-λ(6)-phosphane

The title mol­ecular salts, C(16)H(16)NO(+)·PF(6) (−), (I), and C(21)H(21)N(2) (+)·PF(6) (−), (II), are pyridine derivatives. In compound (I), the cation comprises a methyl N-substituted pyridine ring and a meth­oxy-substituted benzene ring connected by a C=C double bond. The F atoms of the PF(6) (−) anion are disordered over two sets of sites with refined occupancy factors of 0.614 (7):0.386 (7). In compound (II), the cation comprises a pyridine ring attached to unsubstituted phenyl ring and a di­methyl­aniline ring, which are connected by a C=C double bond. The anion is PF(6) (−). In both salts, the cation adopts an E configuration with respect to the C=C bond. The pyridine ring makes a dihedral angle of 9.86 (12)° with the meth­oxy-substituted benzene ring in compound (I) and 11.2 (3)° with the di­methyl­amine-substituted benzene ring in compound (II). In compound (I), the crystal packing is stabilized by weak C—H⋯F inter­molecular inter­actions which result in R (4) (3)(14) ring motifs, forming mol­ecular sheets running parallel to ([Image: see text]03). These are further stabilized by weak P—F⋯π interactions. In compound (II), the crystal packing is stabilized by C—H⋯F inter­actions, which result in R (6) (6)(40) ring motifs, forming mol­ecular sheets running parallel to (101) and these are further connected by π–π inter­actions.