Abstract: The present invention relates to the use of a molybdenum carboxylate as precursor of a catalyst based on molybdenum sulfide, and also to the process for preparing such a catalyst. The invention also relates to certain molybdenum carboxylates.

Abstract: Solutions of rare-earth organophosphates in an organic solvent are prepared by reacting, in such solvent, a rare-earth compound selected from among the rare-earth oxides, hydroxides, carbonates and hydroxycarbonates with an organophosphorus acid and in the presence of a reaction promoter selected from among water, nitric, hydrochloric, acetic, formic and propionic acids and the rare-earth salts of these acids; utilizing a reaction promoter simplifies the method, reduces the reaction time and provides a solution in which the residual solids content may be low.

Abstract: Solutions of rare-earth organophosphates in an organic solvent are prepared by reacting, in such solvent, a rare-earth compound selected from among the rare-earth oxides, hydroxides, carbonates and hydroxycarbonates with an organophosphorus acid and in the presence of a reaction promoter selected from among water, nitric, hydrochloric, acetic, formic and propionic acids and the rare-earth salts of these acids; utilizing a reaction promoter simplifies the method, reduces the reaction time and provides a solution in which the residual solids content may be low.

Abstract: A method for preparing solutions of rare-earth organophosphates in an organic solvent includes a first step of reacting, with an organophosphated acid, a rare-earth compound selected from among the rare-earth oxides, hydroxides, acetates, carboxylates, carbonates and bicarbonates in the absence of the organic solvent of in the presence of the solvent in an amount not exceeding 50% of the final amount if the solvent in the solution; and a second step that includes adding the remaining quantity of the solvent to the product of the reaction of the preceding step.

Abstract: The present invention concerns an addition compound of a carboxylic acid and a rare earth or gallium halide or a rare earth or gallium halogenocarboxylate of the same acid. This compound is obtained by a process in which a rare earth or gallium carboxylate is reacted with HX, X representing a halogen, in a solvent selected from alkanes, cycloalkanes and aromatic solvents and mixtures thereof, the reaction being carried out with an X/rare earth or gallium atomic ratio of less than 3 when preparing a halogenocarboxylate.

Abstract: The present invention concerns an addition compound of a carboxylic acid and a rare earth or gallium halide or a rare earth or gallium halogenocarboxylate of the same acid. This compound is obtained by a process in which a rare earth or gallium carboxylate is reacted with HX, X representing a halogen, in a solvent selected from alkanes, cycloalkanes and aromatic solvents and mixtures thereof, the reaction being carried out with an X/rare earth or gallium atomic ratio of less than 3 when preparing a halogenocarboxylate.

Abstract: A method for preparing tris[(1H,1H,2H,2H-perfluoroalkyl)aryl]phosphites consists in preparing a grignard reagent from an alkoxyhalogenobenzene, then reacting it with a iodo-1H,1H,2H,2H-perfluoroalkane; transforming the alkoxy function of (1H,1H,2H,2H,2H-perfluoroalkyl)alkoxybenzene obtained into a hydroxy function, then reacting (1H,1H,2H,2H-perfluoroalkyl)hydroxybenzene with PCl3. The invention also concerns fluorinated arylphosphites and their use as transition metal ligand for making catalysts to be used in two-phase catalysis with fluorinated phase.