Notizen: Polysulfonylamine, XIX [1] / Kristallstruktur von (1-AcetyI-4-dimethylaminopyridinium)-dimesylamid bei –90 °C / Polysulfonylamines, XIX Crystal Structure of 1-Acetyl-4-dimethylaminopyridinium Dimesylamide at –90 °C

Abstract

The crystal structure of the title compound was determined at —90 °C. It crystallizes in space group PĪ with a = 772.3(2), b = 1071.2(3), c = 1090.4(4) pm, α = 62.65(2), β = 82.71(2), γ = 71.42(2)° and Z = 2. The final R value was 0.031 for 2368 unique observed reflections. The presence of ion pairs in the solid state is observed, with short contacts of 290 pm between the pyridinium nitrogen and an oxygen of the anion. An analysis of the bond lengths suggests that the resonance form with a double bond to the nitrogen of the dimethylamino group and two localized double bonds in the ring, makes a larger contribution to the overall structure than in several similar pyridinium systems; the carbonyl moiety can however be regarded as containing a pure double bond.