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AssigneeExxon Research & Engineering Co.
InventorsMartin B. Dines, Russell R. Chianelli, Theresa A. Pecoraro
Estimating the term…
Finely divided, small particle (0.1 micron or less) small crystallite (about 50 A.times.100 A or less) chalcogenides of manganese, rhenium and technetium are described. These compositions are prepared by mixing the absence of an aqueous solvent, a manganese, rhenium or technetium salt with a source of chalcogenide yielding a precipitate. The manganese, rhenium or technetium salt and the source of chalcogen can be mixed either neat or in the presence of a nonaqueous aprotic solvent. The precipitate which results before removal of the anion salt is a finely divided product. In the case of rhenium dichalcogenide the product possesses a layered structure. The anion salt may be removed by any technique common to the art, pumping under vacuum being one such technique, washing with a suitable solvent being another. A method is described for the preparation of di- and poly-chalcogenides of the formula MX.sub.y wherein M is a metal selected from the group consisting of mangangese, rhenium and technetium, X is a chalcogen selected from the group consisting of sulfur, selenium, tellurium and mixtures thereof, and y is a number ranging from about 1.5 to about 4, preferably about 2, comprising the low temperature, nonaqueous precipitation of said MX.sub.y compounds from mixtures of the salts of said manganese, rhenium and technetium. Said precipitation occurs in the absence of aqueous solvents. The process of the instant invention permits the preparation of materials uncontaminated by water, oxygen or hydrolysis products.
Chalcogenides amorphous to X-ray having a particle size of less than 0.1 micron and a crystallite size of about 50 A.times.100 A or less of the formula MX.sub.y wherein M is a metal selected from the group consisting of technetium and rhenium X is a chalcogen selected from the group consisting of sulfur, selenium and tellurium and y is about 1.5 to about 4.
Chalcogenides of the formula MX.sub.y wherein M is a metal selected from the group consisting of Tc and Re, X is a chalcogen selected from the group consisting of sulfur, selenium, tellurium and mixtures thereof and y is a number ranging from about 1.5 to about 4 prepared by mixing, at a temperature of from -78.degree. C. to 400.degree. C. for a time sufficient for reaction to occur, in the absence of aqueous or protic solvent, solutions of:
A method for the preparation of chalcogenides of the formula MX.sub.y wherein M is a metal selected from the group consisting of technetium and rhenium, X is selected from the group consisting of sulfur, selenium, tellurium and mixtures thereof, and y is a number ranging from about 1.5 to about 4, which comprises reacting, in the absence of aqueous or protic solvent, at a temperature of from -78.degree. to 400.degree. C. for a time sufficient for reaction to occur, a solution of a transition metal salt, the transition metal being selected from the group consisting of manganese, technetium and rhenium, with a source of sulfide, selenide or telluride ions, said source being selected from the group consisting of K.sub.2 X, KHX, Li.sub.2 X, LiHX, NaHX, (NH.sub.4).sub.2 X, Na.sub.2 S, (RNH.sub.3).sub.2 X, (R,R'NH.sub.2).sub.2 X, (R,R'R"NH).sub.2 X wherein R, R' and R" are the same or different C.sub.1 -C.sub.20 alkyl or C.sub.6 to C.sub.20 aryl and X is the chalcogen selected from the group consisting of sulfur, selenium, tellurium and mixtures thereof.
Dependencies are inferred from the claim text.