Crystal and molecular structure of a new cobalt complex of quinine

A new cobalt complex of quinine, C20H25Cl3CoN2O2, was obtained from a mixtu re of saturated alcohol solutions of CoCl2 . 6H(2)O and quinine. The X-ray structure analysis of a single crystal revealed that the complex is a zwitt erion in which the positive charge is localised on the protonated nitrogen atom, N1, of the quinuclidine fragment and the negative charge is shared by the three chlorine atoms. The cobalt atom coordinates the chlorines and th e nitrogen atom, N13, of the quinoline fragment. Each chlorine atom is enga ged in intermolecular hydrogen bonds. One of them is an acceptor of the pro ton of the hydroxyl group, while the two others share the proton of the qui nuclidine nitrogen atom, N1, in a bifurcated hydrogen bond. Quinine has ope n conformation typical for Cinchona alkaloids forming intermolecular hydrog en bonds in the crystalline state.