Structure and IR spectroscopic properties of the anhydrous 4-N,N-dimethylaminopyridinium pentachlorophenolate

Abstract

The structure of the anhydrous 4-N,N-dimethylaminopyridinium pentachlorophenolate has been determined by X-ray diffraction. The crystals are triclinic, space group$\bar P1$ witha=8.637(1),b=8.865(1),c=10.235(1) Å, α=83.80(1), β=86.88(1), γ=89.37(1)° andZ=2. The structure was solved by direct methods and refined to R=0.031 for 1874 non-zero reflections. The N⁺−H...O⁻ hydrogen bond length is 2.579(4) Å and bond angle 165(3)°. The pyridinium ring plane is almost perpendicular to the phenolate ring plane (83.9(5)°). The ionic character and strongly asymmetric proton position in the hydrogen bond has been confirmed by the IR spectrum.