[1H, 15N] heteronuclear single quantum coherence NMR study of the mechanism of aquation of platinum(IV) ammine complexes.
The aquation and hydrolysis of a series of platinum(IV) complexes of the general form cis, trans, cis-[PtCl 2(X) 2( (15)NH 3) 2] (X = Cl (-), O 2CCH 3 (-), OH (-)) have been followed by [ (1)H, (15)N] Heteronuclear Single Quantum Coherence NMR spectroscopy. Negligible aquation (<5%) is observed for the complexes where X = O 2CCH 3 (-) or OH (-) over 3-4 weeks. Aquation of cis-[PtCl 4( (15)NH 3) 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-[PtCl 2( (15)NH 3) 2] (cisplatin). The first aquated species formed from cis-[PtCl 4(NH 3) 2] has one of the axial chloro groups (relative to the equatorial NH 3 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
Murray S
MS
School of Pharmacy and Molecular Sciences, James Cook University, Townsville, Qld, 4811, Australia.
Hall
Matthew D
MD
Berners-Price
Susan J
SJ
Hambley
Trevor W
TW
D000588:Amines / Q000737:chemistry*; D006868:Hydrolysis; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D009942:Organometallic Compounds / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry*
D000588:Amines; D009942:Organometallic Compounds; D014867:Water; D010984:Platinum