Pt2Mo3N and PdPtMo3N:: new interstitial nitrides prepared from freeze-dried precursors

The molybdenum bimetallic and trimetallic nitrides Pt2Mo3N and PdPtMo3N have been synthesized by ammonolysis of the stoichiometric amorphous precursor, obtained by freeze drying of aqueous solutions of the appropriate metal salts. These compounds have been characterized by elemental analysis, energy-dispersive analysis of X-rays, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and thermogravimetry analysis under an oxygen atmosphere. Pt2Mo3N and PdPtMo3N crystallize in the cubic space group P4(1)32 (213), with lattice parameters of a = 6.83586(4) and 6.82542(3) Angstrom, respectively, and form with the unusual filled beta-manganese structure. These compounds are stable under air up to 580 K, the oxidation being complete at 910K. (C) 2004 Elsevier Inc. All rights reserved.