Potassium telluride

These unstable compounds 80 were prepared in approximately 50% yield by reaction of potassium telluride with compounds 81 (76BSB3I9). 

Although this cyclization is similar to those employed in the syntheses of oxygen and sulfur analogs of heterocycles 80 by reaction of 81 with potassium telluride does not allow the preparation of 2-phenyl derivatives of 80. 

In an aqueous medium buffered by sodium acetate, acetylenic ketones react with potassium telluride to give bisfacylvinyl] telluriums. These reactions were performed in the presence of hydroxylamine-Osulfonic acid with the goal of preparing 2-azatellurophenes. The formation of divinyl tellurium compounds competes with the formation of the heterocycles6. 

Dimetbyl-l, 2-tellurazole1 1.7 g (15 mmol) of hydroxylamine O-sulfonic acid are dissolved in 5 ml of water, the solution is cooled to 0°, and 1.23 g (15 mmol) of methyl propynyl ketone are added to the vigorously stirred solution under nitrogen. The solution is stirred for 35 min and 2.5 g (30 mmol) of sodium acetate and 25 ml (l 5 mmol) of a 0.6 molar aqueous solution of potassium telluride are added to the solution over 20 min. The resultant solution is allowed to warm to 20 and is then stirred for 4 h. The reaction mixture is extracted 4 times with 20 ml portions of ethyl acetate and the extract is dried with anhydrous sodium sulfate, filtered, and evaporated to dryness. The residue is sublimed at 70°/0.001 torr and the sublimate recrystallized from acetone yield 0.3 mmol (10%) m.p. 111 . 

VII.12 TELLURIUM, Te (Ar 127 60) - TELLURITES, TeOf Tellurium is less widely distributed in nature than selenium both elements belong to Group VI of the periodic system. When fused with potassium cyanide, it is converted into potassium telluride, K2Te, which dissolves in water to yield a red solution. If air is passed through the solution, the tellurium is precipitated as a black powder (difference and method of separation from selenium). Selenium under similar conditions yields the stable potassium selenocyanide, KSeCN the selenium may be precipitated by the addition of dilute hydrochloric acid to its aqueous solution. 

Potassium tellurides.—The monotelluride, K2Te, was originally produced by Davy12 by direct combination of the elements. At 250° C. the reaction is even more energetic than that between sodium and tellurium. When prepared in an atmosphere of hydrogen, the product has a crystalline structure, and a dark iridescent-purple colour. With water it yields a purple solution, being reprecipitated by alcohol in the form of small, ill-defined crystals.18... 

The original synthesis of diethyl teUnride by Wohler was carried out by treating potassium telluride with ethyl sulfate. The preparation of potassium telluride was rather inconvenient and involved the reduction of elemental tellurium by heating the element at red heat with potassium-hydrogen D-tartrate. An early report of Natta demonstrated that the treatment of aluminium telluride by alcohols or ethers at 250-300 °C is also a promising route to diorganyl tellurides. 

Tellurazoles were isolated in yields not exceeding 10% from reaction mixtures consisting of acetylenic ketones, hydroxylamine 0-sulfonic acid, sodium acetate, and potassium telluride ... 

K4Hf3Xe 7, Hafnium potassium telluride )Hf3K4(Xe2>7(Xe3)), (132938-07-9), 30 86 K48 4Xi3, Xitanate)4-), hexakis(M-)disulfur-5 5 )]dithioxotri-, tetrapotassium. 

Hafnium potassium telluride (HfjK4(Te2)7(Te3)), 30 86 ) 132938-08-0). Potassium zirconium telluride (K4Zr3(Te2>7(Tc3)). 30 86 ) 133494-87-8). Barium bismuth lead thallium oxide... 

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