Kaliumhydrid

Bezeichnung:Kaliumhydrid

CAS-Nr7693-26-7

Englisch Name:Potassium hydride

CBNumberCB5854282

SummenformelHK

Molgewicht40.11

MOL-Datei7693-26-7.mol

Synonyma

Kaliumhydrid

Kaliumhydrid physikalisch-chemischer Eigenschaften

Schmelzpunkt	decomposes [CRC10]
Siedepunkt	316 °C
Dichte	1.54
Flammpunkt	113 °C
storage temp.	Flammables + water-Freezer (-20°C)e area
Löslichkeit	Insoluble in benzene, diethyl ether and carbon disulfide.
Aggregatzustand	dispersion (in mineral oil (~35%))
Farbe	Grayish beige
Wasserlöslichkeit	decomposed by H2O [CRC10]
Sensitive	Moisture Sensitive
InChIKey	NTTOTNSKUYCDAV-UHFFFAOYSA-N
EPA chemische Informationen	Potassium hydride (KH) (7693-26-7)

Sicherheit

Kennzeichnung gefährlicher	F,C
R-Sätze:	11-14/15-34
S-Sätze:	16-26-27-36/37/39-45-43
RIDADR	UN 1409 4.3/PG 1
WGK Germany	3
Selbstentzündungstemperatur	Ignites spontaneously at room temperature in moist air
TSCA	Yes
HazardClass	4.3
PackingGroup	I
HS Code	28500090

Gefahreninformationscode (GHS)

Potassium hydride Chemische Eigenschaften,Einsatz,Produktion Methoden

R-Sätze Betriebsanweisung:
R11:Leichtentzündlich.
R14/15:Reagiert heftig mit Wasser unter Bildung hochentzündlicher Gase.
R34:Verursacht Verätzungen.
S-Sätze Betriebsanweisung:
S16:Von Zündquellen fernhalten - Nicht rauchen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S27:Beschmutzte, getränkte Kleidung sofort ausziehen.
S36/37/39:Bei der Arbeit geeignete Schutzkleidung,Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn möglich, dieses Etikett vorzeigen).
Chemische Eigenschaften
Potassium hydride is available in laboratory quantities only as a 20 – 35 % dispersion in oil. Potassium hydride is a considerably stronger base than lithium hydride or sodium hydride. It is able to remove protons from tertiary alcohols and ketones, a reaction that either does not occur or is very slow when sodium hydride is used. Potassium hydride also reacts with weak Lewis acids, converting sterically hindered boron trialkyls to the corresponding sterically hindered complex borohydrides:
Verwenden
Organic condensations and alkylations.
Verwenden
It is used as a strong reducing agent and inmaking super bases RNHK and ROK(whereRis an alkyl group) (Sullivan andWade 1980).It is sold as 35 wt% dispersion in mineral oil.
Verwenden
Potassium Hydride is used in preparation of Hydroxy-Xanthone derivatives via Isoprenylation followed by Claisen rearrangement starting from Fluoroxanthone derivatives.
Definition
potassium hydride: A white orgreyish white crystalline solid, KH;r.d. 1.43–1.47. It is prepared by passinghydrogen over heated potassiumand marketed as a light grey powderdispersed in oil. The solid decomposeson heating and in contact withmoisture and is an excellent reducingagent. Potassium hydride is a firehazard because it produces hydrogenon reaction with water.
Reaktionen
Potassium hydride acts as a base and as hydride donor. It is used for deprotonation, cyclization-condensation, elimination, and rearrangement reactions, and also as a reducing agent. Potassium hydride undergoes reaction quickly and quantitatively with acids, and of particular note is its capability to rapidly deprotonate tertiary alcohols where sodium hydride or potassium metal do so slowly or not at all. The reactions of metal hydrides take place at the crystal surface. The crystal lattice energies decrease from lithium to cesium hydride, and potassium hydride appears to have the optimal lattice energy and hydride radius for surface reactions. The presence of 18-crown-6 enhances the reactivity of potassium hydride, The crown ether can operate as a phase-transfer agent or as a simple “pickling” agent of the potassium hydride surface, dissolving the formed inorganic salts. Potassium hydride is usually superior to lithium and sodium hydride in the reactions. Unusually active potassium hydride can be prepared easily from hydrogen and superbasic reagents (t-BuOK-TMEDA) in hexane. “Superactive potassium hydride” is very active in deprotonation as well as in reduction. The reactivity of commercially available potassium hydride, which is prepared by the reaction of hydrogen gas with elemental potassium, depends upon the impurities in different lots (mainly potassium or its reaction products), thus leading to side reactions and variable yields. The superactive metal hydride contains no alkali metal.
Allgemeine Beschreibung
This product has been enhanced for energy efficiency.
Hazard
Dangerous fire and explosion risk, evolves toxic and flammable gases on heating and on expo- sure to moisture.
Health Hazard
Potassium hydride react with the moisture on skin and other tissues to form highly corrosive sodium and potassium hydroxide. Contact of these hydrides with the skin, eyes, or mucous membranes causes severe burns; thermal burns may also occur due to ignition of the liberated hydrogen gas.
Health Hazard
The toxicity data on potassium hydride arenot reported in the literature. In the pure state, this compound should be highly corrosiveby inhalation, ingestion, and skin contact.It yields potassium hydroxide, whichis also very corrosive, when reacted withmoisture.
Brandgefahr
Potassium hydride is flammable solid that ignite on contact with moist air. Potassium hydride presents a more serious fire hazard than sodium hydride. The mineral oil dispersions do not ignite spontaneously on exposure to the atmosphere. Sodium hydride and potassium hydride fires must be extinguished with a class D dry chemical extinguisher or by the use of sand, ground limestone, dry clay or graphite, or "Met-L-X ? " type solids. Water or CO 2 extinguishers must never be used on sodium and potassium hydride fires.
Flammability and Explosibility
Potassium hydride and sodium hydride are flammable solids that ignite on contact with moist air. Potassium hydride presents a more serious fire hazard than sodium hydride. The mineral oil dispersions do not ignite spontaneously on exposure to the atmosphere. Sodium hydride and potassium hydride fires must be extinguished with a class D dry chemical extinguisher or by the use of sand, ground limestone, dry clay or graphite, or "Met-L-X?" type solids. Water or CO2 extinguishers must never be used on sodium and potassium hydride fires.
Sicherheitsprofil
Dangerous fire hazard by chemical reaction. Ignites spontaneously in air. Moderate explosion hazard when exposed to heat or by chemical reaction. Wdl react with water, steam, or acids to produce H2 which then igmtes. Can react vigorously with oxidizing materials. To fight fire, use CO2, dry chemical. Potentially explosive reactions with 0-2,4- dnitrophenylhydroxylamine, fluoroalkenes. Ignites on contact with air, oxygen + moisture, fluorine. Incompatible with Cl2, acetic acid, acrolein, acrylonitrile, (CaC + Cl2), ClO2, (H202 + Cl2), (CHFL + CH,OH), 1,2-dchloroethylene, maleic anhydride, (n-methyl-n-nitrosourea + CH2Cl2), nitroethane, NCb, nitromethane, nitroparaffins, o-nitrophenol, nitropropane, n-nitrosomethylurea, (nitrosomethylurea + CH2Cl2), H20, trichloroethylene, tetrahydrofuran, tetrachlorethane. When heated to decomposition it emits highly toxic fumes of K2O. See also POTASSIUM and HYDRIDES.
Lager
Safety glasses, impermeable gloves, and a fire-retardant laboratory coat should be worn at all times when working with these substances. These hydrides should be used only in areas free of ignition sources and should be stored preferably as mineral oil dispersions under an inert gas such as argon.
Inkompatibilitäten
Potassium hydride and sodium hydride react violently with water, liberating hydrogen, which can ignite. Oil dispersions of these hydrides are much safer to handle because the mineral oil serves as a barrier to moisture and air. Potassium hydride may react violently with oxygen, CO, dimethyl sulfoxide, alcohols, and acids. Explosions can result from contact of these compounds with strong oxidizers. Potassium hydride is generally more reactive than sodium hydride.
Waste disposal
Excess potassium or sodium hydride and waste material containing these substances should be placed in an appropriate container under an inert atmosphere, clearly labeled, and handled according to your institution's waste disposal guidelines. Experienced personnel can destroy small quantities of sodium hydride and potassium hydride by the careful dropwise addition of t-butanol or iso-propanol to a suspension of the metal hydride in an inert solvent such as toluene under an inert atmosphere such as argon. Great care must be taken in the destruction of potassium hydride because of its greater reactivity. The resulting mixture of metal alkoxide should be placed in an appropriate container, clearly labeled, and handled according to your institution's waste disposal guidelines.

Potassium hydride Upstream-Materialien And Downstream Produkte

Kaliumhydrid Anbieter Lieferant Produzent Hersteller Vertrieb Händler.

7693-26-7, Potassium hydride Verwandte Suche:

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