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Feasibility of a two-metal, four-purine nucleobase quartet motif
Michael Roitzsch1, Bernhard Lippert
1Fachbereich Chemie, Universität Dortmund, 44221 Dortmund, Germany.
Abstract:
A mixed-purine nucleobase complex of composition trans-[(NH(3))(2)Pt(9-EtA-N1)(9-MeHx-N7)](NO(3))(2).2H(2)O (1) (9-EtA = 9-ethyladenine; 9-MeHx = 9-methylhypoxanthine) has been prepared and characterized by X-ray crystallography. Cations of 1 are self-complementary as far as hydrogen bonding properties are concerned and form H bonded dimers, containing four intermolecular hydrogen bonds in addition to two intramolecular ones. The resulting mixed-purine square is considered a model compound for a putative mixed-purine tetrad consisting of two adenines and two guanines. In this model, the one-metal, four-nucleobase quartet motif, as seen in guanine or uracil quartets of nucleic acids, with the metal located in the center of the base tetrad, has been altered to a two-metal, four-nucleobase motif, with the two metal ions localized at the periphery.
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