The reaction of 2′-deoxyribonucleoside with the α-pyrrolidonate-bridged Pt(III) dinuclear complex

Of the four 2′-deoxyribonucleosides (dA, dG, dC, and dT), only dG coordinated to the α-pyrrolidonate-bridged platinum(III) dinuclear complex [Pt2(NH3)4(C4H6NO)2(NO3)(H2O)](NO3)3 (1) with N7 of the guanine base by replacing the NO3 − ligand. The 2′-deoxyguanosine platinum(III) dinuclear complex [Pt2(NH3)4(C4H6NO)2(C10H13N5O4)(SO4)](SO4)·4H2O (2) was prepared by oxidation of the platinum (+2,25) blue complex [Pt4(NH3)8(C4H6NO)4](NO3)5·2H2O (3) with Na2S2O8 in the presence of dG. The X-ray diffraction analysis confirmed the structure of complex 2. The 1H NMR spectroscopy showed that the complex is stable at pH<4, but free dG is liberated at pH 7.