<unk>  is a quaternary ammonium cation with an asymmetric carbon atom. It is used as the pure R-enantiomer. The salt,<unk> , is a crystalline powder that is hardly soluble in water or ethanol.
Aclidinium bromide
Umeclidinium bromide
Chloropicrin
Tiratricol
Bifluranol
Hydrastine
Brinzolamide
Pirisudanol