NITRATO COMPLEXES OF PLATINUM(IV) WITH CESIUM CATIONS

Two novel platinum(IV) nitrate complexes, Cs-2[Pt(NO3)(6)] (1) and Cs-2[Pt-2(mu-OH)(2)(NO3)(8)] (2), are prepared by adding cesium nitrate to a solution of platinum(IV) hydroxide in nitric acid. It is established that the main reaction product is the Cs-2[Pt(NO3)(6)] mononuclear complex, while Cs-2[Pt-2(mu-OH)(2)(NO3)(8)] is formed only after the removal of the first portion of the precipitate and subsequent long-term storage of the mother liquor. The structures of the salts are studied by XRD. Crystal data for Cs-2[Pt(NO3)(6)] (1): a = 9.7346(3) A, b = 11.5072(3) angstrom, c = 13.6813(2) angstrom, space group Pbcn, Z = 4. Crystal data for Cs-2[Pt-2(mu-OH)(2)(NO3)(8)] (2): a = 7.0889(2) angstrom, b = 14.2216(6) angstrom, c = 10.7931(4) angstrom, ss = 91.776(1)degrees, space group P2(1/n), Z = 2. It is shown that NO3 ligands in (1) occupy atypical positions. The geometry of the complex anion in (2) is similar to the one described for (Me4N)(2)[Pt-2(mu-OH)(2)(NO3) (8)]. Powdered samples of (1) and those of a mixture of (1) and (2) are characterized by powder XRD and IR spectroscopy. The obtained compounds are shown to be stable upon long-term storage in air.