Acid- and Base-Iinduced Reversible Transformations of Platinum Carbonyl Clusters in Water-Acetone Solutions and on Alumina Surface
Статья (Full article),
Russian Journal of Inorganic Chemistry
, E-ISSN: 1531-8613
Boreskov Institute of Catalysis Siberian Division Russian Academy of Sciences, ul. Neftezavodskaya 54
Acid- and base-induced interconversions of the isostoichiometric platinum carbonyl clusters [Pt3(CO)6]n2- (n = 2, 3, 5, ∼10) in water-acetone solutions were studied by IR spectroscopy and NMR. Redox transformations of the clusters are accompanied by reversible variation of n: [Pt3(CO)6]∼102- equation presented [Pt3(CO)6]52- equation presented [Pt3(CO)6]2-32-. The rates of both the forward and back reactions increase with water concentration, suggesting that OH- and H+ ions (whose concentrations grow with [H2O] because of increasing degrees of NaOH and HCl dissociation) are involved in the transformations. On strongly acidic alumina surface, Pt6 transforms into Pt15, as it does in strongly acidic solutions. The low-n cluster can be supported onto γ-Al2O3 in the presence of a competing adsorbate binding to strongly acidic surface sites.