Crystal structures of anhydrous and hydrated N-benzyl­cinchonidinium bromide

N-benzyl­cinchonidinium bromide, C(26)H(29)N(2)O(+)·Br(−), with the systematic name (R)-[(2S,4S,5R)-1-benzyl-5-ethenyl-1-azoniabi­cyclo­[2.2.2]octan-2-yl](quinolin-4-yl)­methanol bromide, is a quaternary ammonium salt of the cinchona alkaloid cinchonidine. This salt is widely used as a chiral phase-transfer catalyst and chiral resolution agent. Both classical and non-classical hydrogen-bonding inter­actions, as well as anion effects have been shown to play key mechanistic roles in the catalysis of cinchona alkaloids. In an effort to understand the effects of water on these inter­molecular inter­actions, the structures of anhydrous N-benzyl­cinchonidinium bromide, (I), and the sesquihydrate, C(26)H(29)N(2)O(+)·Br(−)·1.5H(2)O, (II), were determined.