Acta Cryst. (2013). E69, o1711
[ doi:10.1107/S1600536813028754 ]
Abstract: The title compound, C10H22N22+·2Br-, was synthesized via reduction of 2,2'-dipyridyl with Ni-Al alloy/KOH, followed by separation of diastereoisomers (meso and rac) by recrystallization from ethanol. Although the two bridging C atoms are optically active, these two chiral centers adopt an (S,R) configuration; thus, the title compound contains an achiral meso form of 2,2'-bipiperidine. Both of the piperidinium rings adopt chair conformations, and the two N atoms are trans to each other; an inversion center is located in the mid-point of the central C-C bond. The conformation of the organic moiety resembles that of 1,1'-bi(cyclohexane). The organic diammonium cations are linked to each other through hydrogen bonding with bromide counter-ions, each of which forms two hydrogen bonds (N-HBr) with two adjacent organic cations, thus linking the latter together in sheets parallel to (100).
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