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Crystal and molecular structure of a new cobalt complex of quinine
P Pytel1, B J Oleksy, J Sliwiński
1Faculty of Chemistry, Jagiellonian University, Kraków, Poland.
Abstract:
A new cobalt complex of quinine, C20H25Cl3CoN2O2, was obtained from a mixture of saturated alcohol solutions of CoCl2 6H2O and quinine. The X-ray structure analysis of a single crystal revealed that the complex is a zwitterion 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 the nitrogen atom, N13, of the quinoline fragment. Each chlorine atom is engaged in intermolecular hydrogen bonds. One of them is an acceptor of the proton of the hydroxyl group, while the two others share the proton of the quinuclidine nitrogen atom, N1, in a bifurcated hydrogen bond. Quinine has open conformation typical for Cinchona alkaloids forming intermolecular hydrogen bonds in the crystalline state.
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