Tris{trans-4-[p-(N,N-diethyl­amino)styryl]-N-methyl­pyridinium} dodecatungstophosphate

In the title compound, (C₁₈H₂₃N₂)₃[PW₁₂O₄₀], three trans-4-[p-(N,N-diethyl­amino)styryl]-N-methyl­pyridinium cations lie around one dodecatungstophosphate anion and they form an infinite three-dimensional assembly via electrostatic forces. The three similar cations are distorted to different extents because of different packing environments, e.g. the dihedral angles between the benzene rings and the pyridine rings are 3.4 (1)-29.0 (3)°. The Keggin structure polyanion is also severely distorted.

Tetrakis(1,4-dimethyl­pyridinium) dodeca­molybdo­phosphate nitrate

In the title compound, (C₇H₁₀N)₄[PMo₁₂O₄₀]NO₃, the asymmetric unit contains two 1,4-dimethyl­pyridinium (DMP) cations, one half of a nitrate anion perpendicular to the mirror plane and one half of a dodeca­molybdophosphate (PMo₁₂) anion. Because of orientational disorder, a crystallographic centre of symmetry appears at the central P atom of the PMo₁₂ anion, although the PO₄ moiety has a tetra­hedral structure and does not have a centre of symmetry. The PMo₁₂ anions show a disordered `pseudo-Keggin' structure and they are linked into an infinite three-dimensional assembly by DMP cations, via electrostatic forces and C—H...O inter­actions.

1,4-Dimethyl­pyridinium triiodide

In an attempt to synthesize 1,4-dimethyl­pyridinium dodeca­tungsto­phosphate and 1,4-dimethyl­pyridinium dodeca­molybdo­phosphate, the title compound, C₇H₁₀N⁺·I₃^-, was obtained as a by-product. The crystal structure contains a disordered 1,4-dimethyl­pyridinium cation and a triiodide anion.