Potassium metalation

Metallic potassium is available commercially for about 40/lb in small quantities. 

Potassium dissolves in Hquid ammonia, but the conversion of a small amount of the metallic potassium to the metallic amide takes several days. By applying the same technique using sodium metal, sodium amide [7782-92-5] NaNH2, a white soHd, can be formed. 

Metals and Metal Derivatives, Silane reacts with alkah metals dissolved in various solvents, forming as the chief product the silyl derivative of the metal, potassium being the most commonly studied, eg, KSiH [13812-63-OJ (27—30). When 1,2-dimethoxyethane or bis(2-methoxyethyl)ether are used as solvents, two competing reactions occur, where M is an alkah metal. 

Reaction with hydrogen at 220°C in the presence of reduced nickel catalyst results in total decomposition to hydrogen chloride and carbon. An explosive reaction occurs with butylUthium in petroleum ether solution (4). Tetrachloroethylene also reacts explosively with metallic potassium at its melting point, however it does not react with sodium (5). 

The spectacular success (in 1807) of Humphry Davy, then aged 29 y, in isolating metallic potassium by electrolysis of molten caustic potash (KOH) is too well known to need repeating in detail." Globules of molten sodium were similarly prepared by him a few days later from molten caustic soda. Earlier experiments with aqueous solutions had been unsuccessful because of the great reactivity of these new elements. The names chosen by Davy reflect the sources of the elements. 

Tire reduction of TAF 100 by metallic potassium resulted in the formation at room temperature of the stable anion radical 109, which yielded a simple nine-line ESR pattern caused by the two sets of two equivalent nitrogens with Ani = 3.40 and An2 = 0.81 G (79JOC3211).Tlie nonequivalency of the nitrogens was explained by the association of the potassium cation with one of the two diazacylopentadienyl moieties (Scheme 44). 

JOM(215)255). Similar nickel sandwiches and triple-deckers are known (77AGE468, 78ZN(B)1410, 81 JOM(207)343). The latter can be reduced to the anionic species using metallic potassium (81JOM(208)137). 

Kali-kugel, /. potash bulb, -lauge, /. potash lye, caustic potash solution, -losung, /. potash solution, -metall, n. (metallic) potassium. -olivenolseife, /. potash olive oil soap, -praparat, n. potash (or potassium) preparation. -reibe,/. (Petro. ) potash series, -roh-salz, n. crude potassium salt, -salpeter, m. 

Berzelius reported on the results of the first reduction of tantalum from K2TaF7 using metallic potassium in 1825 [574]. About thirty years later, Rose obtained sufficiently pure tantalum in an interaction between Na2TaF7 and metallic sodium [575]. The methods elaborated by Berzelius and Rose provided a basis for the development of the industrial-scale production of tantalum by the reduction of K2TaF7 using metallic sodium. 

Cobalt at a dilution of 1 gg per liter was completely recovered and successfully determined by use of an ion-exchange membrane. Similar results were obtained with other heavy metals. Potassium in amounts from 5 to 150 /xg inJ75 ml.was extracted from aqueous solutions and from mica surfaces, on which it is present as an exchangeable ion.26... 

Niepce s Incendiary Composition. Contained benz, petroleum or carbon disulfide with a small piece of metallic potassium or Ca phosphate as igniter. Potassium was later replaced with metallic sodium Ref Daniel (1902), 153... 

Its oxidising character plays a role in all other reactions. Surprisingly, it is thought to form explosive dichlorine oxide with chlorine. It leads to a and very exothermic reaction with disulphur dichloride and detonations with metals potassium, K-Na alloy, magnesium with phosphorus and anhydrous or hydrated hydrazine. 

A 20 g sample, prepared and stored in a dry box for several months, developed a thin crust of oxidation/hydrolysis products. When the crust was disturbed, a violent explosion occurred, later estimated as equivalent to 230 g TNT. A weaker explosion was observed with potassium tetrahydroaluminate. The effect was attributed to superoxidation of traces of metallic potassium, and subsequent interaction of the hexahydroaluminate and superoxide after frictional initiation. Precautions advised include use of freshly prepared material, minimal storage in a dry diluent under an inert atmosphere and destruction of solid residues. Potassium hydrides and caesium hexahydroaluminate may behave similarly, as caesium also superoxidises in air. 

Potassium dioxide Metals Potassium permanganate Antimony, etc. 

Lead(II) oxide Non-metals Lead(IV) oxide Non-metals Nitric acid Non-metals Nitrogen oxide Non-metals Nitrosyl fluoride Metals, etc. Nitryl fluoride Non-metals Oxygen difluoride Non-metals Potassium nitrite Boron Potassium nitrate Non-metals Silver difluoride Boron, etc. Sodium peroxide Non-metals... 

Freeder, B. G. et al., J. Loss Prev. Process Ind., 1988, 1, 164-168 Accidental contamination of a 90 kg cylinder of ethylene oxide with a little sodium hydroxide solution led to explosive failure of the cylinder over 8 hours later [1], Based on later studies of the kinetics and heat release of the poly condensation reaction, it was estimated that after 8 hours and 1 min, some 12.7% of the oxide had condensed with an increase in temperature from 20 to 100°C. At this point the heat release rate was calculated to be 2.1 MJ/min, and 100 s later the temperature and heat release rate would be 160° and 1.67 MJ/s respectively, with 28% condensation. Complete reaction would have been attained some 16 s later at a temperature of 700°C [2], Precautions designed to prevent explosive polymerisation of ethylene oxide are discussed, including rigid exclusion of acids covalent halides, such as aluminium chloride, iron(III) chloride, tin(IV) chloride basic materials like alkali hydroxides, ammonia, amines, metallic potassium and catalytically active solids such as aluminium oxide, iron oxide, or rust [1] A comparative study of the runaway exothermic polymerisation of ethylene oxide and of propylene oxide by 10 wt% of solutions of sodium hydroxide of various concentrations has been done using ARC. Results below show onset temperatures/corrected adiabatic exotherm/maximum pressure attained and heat of polymerisation for the least (0.125 M) and most (1 M) concentrated alkali solutions used as catalysts. 

Hydrazinium nitrate Alone, or Metals Hydrogen sulfide Metals Potassium dioxide Metals Sulfuric acid Copper... 

After a few minutes reflux at 12°C, a mixture of the hydride (0.01 mol) and a fluoroalkene (0.02 mol) exploded violently. This was attributed to possible presence of metallic potassium in the hydride, causing polymerisation or formation of a fluoroacetylene. 

The earlier references, which state that this powerful oxidant is stable when pure, but explosive when formed as a layer on metallic potassium [1,2], are not wholly correct [3], because the superoxide is manufactured uneventfully by spraying the molten metal into air to effect oxidation [4], Previous incidents appear to have involved the explosive oxidation of unsuspected traces of mineral oil or solvents [3]. However, mixtures of the superoxide with liquid or solid potassium-sodimn alloys will ignite spontaneously after an induction period of 18 min, but combustion while violent is not explosive [3], The additional presence of water (which reduces the induction period) or hydrocarbon contaminant did produce explosion hazards under various circumstances [5], Contact of liquid potassium with the superoxide gives no obvious reaction below 117°C and a controlled reaction between 117 and 177°C, but an explosive reaction occurs above 177°C. Heating at 100°C/min from IT caused explosion at 208°C [6],... 

Oxygen (Liquid) Metals Potassium chlorate Metals MRH 9.50/63... 

Iodine pentafluoride Metals Lead(IV) oxide Metals Nitryl fluoride Metals Potassium perchlorate Metal powders Sodium peroxide Metals See other metals... 

When naphthalene is reduced in liquid ammonia by metallic potassium, evaporation of excess ammonia gives the solvated solid potassium naphthalide (K2 ... 

Chlorine Metals Nitiyl fluoride Metals Peroxyformic acid Metals Potassium perchlorate Metal powders... 

Potassium chlorate Charcoal, etc., or Non-metals Potassium chlorite Sulfur MRH 3.22/82... 

Dichlorine oxide Oxidisable materials Iodine pentafluoride Metals Iodine Metals Nitrosyl fluoride Metals Perchloric acid Antimony(III) compounds Potassium dioxide Metals Potassium permanganate Antimony, etc. 

Chromium trioxide Selenium Fluorine Non-metals Potassium bromate Non-metals Silver(I) oxide Non-metals Sodium peroxide Non-metals... 

See Ammonium nitrate Metals Chlorine Metals Chlorine trifluoride Metals Copper(II) nitrate Tin Fluorine Metals Iodine bromide Metals Iodine heptafluoride Metals Potassium dioxide Metals Sodium peroxide Metals Sulfur Metals Tellurium Tin... 

Potassium chlorate Metals Potassium nitrate Metals... 

Zheng et al. treated potassium [l,2,4]diazaphospholides, obtained from the reaction of 3,5-disubstituted-[l,2,4]diazaphospholes with metallic potassium in THF, with [Cp RuCl]4 to afford [(T75-dp)RuCp ] type pseudoruthenocene complex (106) (Scheme 33). Sandwich structure with almost eclipsed orientation of two n-bonded ligands has been confirmed by X-ray crystal structure determination [110], Catalytic application of [(rf-dp)RuCp ] complexes in the Heck reaction has also been investigated [111]. 

In the reaction flask is placed 600 cc. of commercial ter/.-butyl alcohol (Note 1), and the air in the flask is displaced by dry nitrogen gas. Then 29 g. (0.75 gram atom) of metallic potassium is added, in portions, to the alcohol. The mixture is heated on a water bath until all the potassium has dissolved, and then 68 g. (0.5 mole) of o-formotoluide (Note 2) is added and brought into solution. The condenser is set for distillation with a filter flask as the receiver this flask is protected from the air by connecting it to the trap used in the initial operation. The reaction flask is... 

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