Structure and thermal properties of double complex salts [RuNO(NH3)4(H2O)]2[MCl4]Cl4·2H2O, M = Pt, Pd

Abstract

Double complex salts (DCS) [RuNO(NH3)4(H2O)]2[MCl4]Cl4·2H2O, M = Pt (I) and Pd (II), are prepared and characterized using IR spectroscopy, single crystal and powder X-ray diffraction, and thermogravimetric analysis. Crystalline phases of I and II are isostructural (P2(1)/n space group) and have the following crystallographic characteristics: a = 6.689 A, b = 15.609 A, c = 12.348 A, V = 1289.1 A3, Z = 2, dx = 2.425 g/cm3 (I) and a = 6.637 A, b = 15.521 A, c = 12.244 A, V = 1261.2 A3, Z = 2, dx = 2.255 g/cm3 (II). The thermolysis of the obtained DCS in the hydrogen atmosphere affords two-phase mixtures of limited solid solutions of the metals: hcp for ruthenium-based ones and fcc for Pt or Pd based solutions. On decomposition in the helium atmosphere the products contain a minor amount of RuO2. For the phases obtained during thermolysis the parameters are determined and the compositions are estimated. The heating of I to 400°C in the helium-air atmosphere yields a nanocrystalline composite Pt+RuO2 with CSR of ∼20 nm.