The aquation and hydrolysis of a series of platinum(IV) complexes of the general form cis, trans, cis-[PtCl2(X)(2)((NH3)-N-15)(2)] (X = Cl-, O2CCH3-, OH-) have been followed by [H-1, N-15] Heteronuclear Single Quantum Coherence NMR spectroscopy. Negligible aquation (<5%) is observed for the complexes where X = O2CCH3- or OH- over 3-4 weeks. Aquation of cis-[PtCl4((NH3)-N-15)(2)] (1) is observed, and the rate of aquation increases with increasing pH and upon the addition of 0.01 mol equiv of the platinum(II) complex cis-[PtCl2((NH3)-N-15)(2)] (cisplatin). The first aquated species formed from cis-[PtCl4(NH3)(2)] has one of the axial chloro groups (relative to the equatorial NH3 ligands) replaced by an aqua/hydroxo ligand. The second observed substitution occurs in an equatorial position. Peaks that are consistent with five of the eight possible aquation species were observed in the NMR spectra.
Davies, M. S., Hall, M. D., Berners-Price, S., & Hambley, T. W. (2008). [1H, 15N] Heteronuclear Single Quantum Coherence NMR Study of the Mechanism of Aquation of Platinum(IV) Ammine Complexes. Inorganic Chemistry, 47(17), 7673-7680. https://doi.org/10.1021/ic8006734