Quinine di-hydro-chloride hemihydrate.

Numerous non-covalent inter-actions link together discrete mol-ecules in the crystal structure of the title compound, 2C20H26N2O2 2+·4Cl-·H2O {systematic name: 4-[(5-ethenyl-1-azonia-bicyclo-[2.2.2]octan-2-yl)(hy-droxy)meth-yl]-6-meth-oxy-quinolin-1-ium dichloride hemihydrate}. A combination of hydrogen bonding between acidic H atoms and the anions in the asymmetric unit forms a portion of the observed hydrogen-bonded network. π-π inter-actions between the aromatic portions of the cation appear to play a role in the formation of the long-range ordering. One ethyl-ene double bond was found to be disordered. The disorder extends to the neighboring carbon and hydrogen atoms.