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Autori: Florina Dumitru, Eddy Petit, Arie van der Lee, Mihail Barboiu
Editorial: European Journal of Inorganic Chemistry (Cover Picture), 21, p.4255-4262, 2005.
We describe in this paper a study of the equilibrium binding of Zn2+ to the
binary mixtures of tridentate terpy-type ligands 1-3, leading to the formation of the dynamic mixture
of homo- (4-6) and hetero- (7-9) coordination compounds. We report the crystal structures of five such complexes (4, 5, 7-9) which assemble into complementary duplex compounds, and further selforganize into double helical- or lamellar-type architectures in the solid state.
The ligand exchange between homoduplex complexes in solution led to the preferential formation of the heteroduplex complexes. As might expected these processes display a statistical distribution of homoduplex : heteroduplex : homoduplex = 1:2:1 complexes for the mixtures resulted from 4 : 6 and
5 : 6 ligands. However the complex 8 is preferred in a 4 : 5 mixture which present a composition of
1:4:1 (amplification factor of about 33%). The X-ray structural determinations of the selected single crystals resulting from the stoichiometric mixtures of homoduplex complexes led to unique heteroduplex superstructures 7-9 in the solid state. The present results presents the solid state structures of homo- and heterocomplexes resulted from terpyridine-type ligands 1-3 and Zn2+ metal ions. The heteroduplex Zn2+ complexes 7-9 are quantitatively crystallized in the solid state by
statistical (7, 9) and structural (8) driven selection in solution from a binary mixture of the terpyridine-type complexes and then be trapped by crystallisation in the solid state.
Cuvinte cheie: Crystal engineering, N ligands, Supramolecular chemistry , Ternary complexes, Zinc