Migration of a cis-(NH3)2PtII moiety along two adenine nucleobases, from N1 to N6, is markedly facilitated by additional PtII entities coordinated to N7.
Adenine acidification as a consequence of simultaneous PtII binding to N1 and N7 facilitates deprotonation of the exocyclic N(6)H2 group and permits PtII migration from N1 to N6 under mild conditions. Starting from the trinuclear complex cis-[(NH3)2Pt(N1-9-MeA-N7)2{Pt(NH3)3)}2]6+ (3), stepwise migration of cis-(NH3)2PtII takes place in the alkaline aqueous solution to give initially cis-[(NH3)2Pt(N1-9-MeA-N7)(N6-9-MeA--N7){Pt(NH3)3}2]5+ (4) and eventually cis-[(NH3)2Pt(N6-9-MeA--N7)2{Pt(NH3)3}2]4+ (5) (with 9-MeA = neutral 9-methyladenine, 9-MeA- = 9-methyl-adenine monoanion, deprotonated at N6). The migration process has been studied by 1H NMR spectroscopy, and relevant acid-base equilibria have been determined. 5 has been crystallized as its nitrate salt and has been characterized by X-ray crystallography. The precursor of 3, [(NH3)3Pt (9-MeA-N7)]Cl2.2H2O (2) has likewise been studied by X-ray analysis.
Añorbe
Marta Garijo
MG
Fachbereich Chemie, Universität Dortmund, 44221 Dortmund, Germany.
Welzel
Thea
T
Lippert
Bernhard
B
D000225:Adenine / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D010984:Platinum / Q000737:chemistry*