Platinum(IV) complexation with the nitrate ion in aqueous solutions according to 195Pt, 15N, 14N, and 17O NMR data

Abstract

Solutions of platinum(IV) nitrate were studied by 195Pt, 15N, 14N, and 17O NMR and IR and Raman spectroscopy. It was found that in nitric acid, two interrelated systems of nitrate complexes, mono- and polynuclear ones, coexist. The complexes predominating in concentrated solutions are [Pt2(μ-OH)(μ-NO3)(NO3)2(H2O)6 − x(OH)x](4 − x)+, [Pt4(μ-OH)3(μ-NO3)3(NO3)3(H2O)9 − x(OH)x](7 − x)+, [Pt4(μ-OH)4(μ-NO3)2(NO3)4(H2O)8 − x(OH)x](6 − x)+, and [Pt4(μ-OH)6(NO3)3(H2O)16 − x(OH)x](7 − x)+.