The structure and stability of sulfated alumina and titania

Fine-particle metal chromites (MCr2O4, where M = Mg, Ca, Mn, Fe, Co, Ni, Cu, and Zn) have been prepared by the combustion of aqueous solutions containing the respective metal nitrate, chromium(III) nitrate, and urea in stoichiometric amounts. The mixtures, when rapidly heated to 350°C, ignite and yield voluminous chromites with surface areas ranging from 5 to 25 m2/g. MgCr2O4, sintered in air at 1500°C for 5 h, has a density of 4.0 g/cm3.

Combustion Synthesis of Metal Chromite Powders

Lattice vibration spectra. LIX. Single crystal infrared and Raman studies of spinel type oxides

Introduction T metal oxides (TMO) like Fe2O3, CuO, MnO2, CuCr2O4, etc., form a very popular group of catalysts for burning rate modification of composite solid propellants. Although it is well known that these oxides affect the decomposition characteristics of polymers and oxidizers like ammonium perchlorate (AP)' and potassium perchlorate, (KP) the exact mechanism of the effect on solid propellants is by no means clear even today. Much fragmentary literature is available on the effect of these oxides on propellant burning and decomposition, oxidizer burning and decomposition, and sandwich and condensed mixture combustion. It is the purpose of this review to bring the material together so that a comprehensive picture can be drawn of the mechanism of the action of these catalysts. It may be mentioned here that these oxides also catalyze hydrocarbon oxidation reactions by inducing free radical decomposition of hydroperoxides (formed by the contact of oxidizer and hydrocarbon).

Effect of Transition Metal Oxides on Decomposition and Deflagration of Composite Solid Propellant Systems: A Survey

In recent years, research in organophosphorus chemistry has mainly focused in designing newer and better phosphorus ligands for synthesizing novel metal complexes with improved catalytic activities. Aminophosphines [tricoordinate phosphorus(III)–nitrogen systems] are considered as versatile compounds owing to the presence of nitrogen centres which, in principle, can influence additional reactivity features. They are quite sensitive to air and moisture due to the presence of polar PN bond(s). In spite of this, research in aminophosphine chemistry is gaining momentum day-by-day and this is due mainly to one reason: their rich behaviour as ligands in metal complex chemistry and subsequently in catalysis. Their role as synthons in inorganic heterocyclic chemistry has also helped produce new types of heterocycles. In this paper, the chemistry of simple acyclic aminophosphines (synthesis, characterization, reactivity and applications) is covered and particular focus is given to their ability to form chalcogenides along with their role played as ligands in coordination chemistry and as synthons in inorganic heterocyclic chemistry. Copyright © 2009 John Wiley & Sons, Ltd.

M.R. Udupa

Papers

Thermal decomposition of -onium type oxalates

Thermal behaviour of cetyl trimethylammonium perchlorate

Solid state reactions in the system oxalate-bromate-chromium(III) oxide

Preparation of chromium(III) spinels by the solid state reaction between potassium dichromate and hydrated metal chlorides

Thermal decomposition of thallium(I) perchlorate in presence of chromium(III) oxide