Natriumhydrid Chemische Eigenschaften,Einsatz,Produktion Methoden
R-Sätze Betriebsanweisung:
R15:Reagiert mit Wasser unter Bildung hochentzündlicher Gase.
R36:Reizt die Augen.
S-Sätze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S43:Zum Löschen . . . (vom Hersteller anzugeben) verwenden (wenn Wasser die Gefahr erhöht, anfügen: "Kein Wasser verwenden").
S7/8:Behälter trocken und dicht geschlossen halten.
S24/25:Berührung mit den Augen und der Haut vermeiden.
S7:Behälter dicht geschlossen halten.
Aussehen Eigenschaften
HNa, 60 %ige Suspension in Paraffinöl. Graue Suspension, fast geruchlos.
Gefahren für Mensch und Umwelt
Verursacht Verätzungen. Einatmen kann zu Ödemen der Atmungsorgane führen. Verschlucken führt zu Verätzungen von Mund, Rachen, Speiseröhre und Magen/Darm mit Perforationsgefahr. Bei Augenkontakt besteht Erblindungsgefahr.
Bildet mit Wasser hochentzündliche Gase.
Nicht mit Wasser, Säuren und Alkoholen in Berührung bringen.
Schutzmaßnahmen und Verhaltensregeln
Schutzhandschuhe als kurzzeitiger Staub-/Spritzschutz.
Verhalten im Gefahrfall
Vorsichtig trocken aufnehmen. Mit niederen Alkoholen unschädlich machen.
Mit trockenem Sand oder Zement abdecken.
Ungeeignetes Löschmittel: Wasser.
Setzt im Kontakt mit Wasser Wasserstoff frei. Kann sich mit Luftfeuchtigkeit selbst entzünden.
Erste Hilfe
Nach Hautkontakt: Mit reichlich Wasser abwaschen. Abtupfen mit Polyethylenglycol 400.
Nach Augenkontakt: Mit reichlich Wasser bei geöffnetem Lidspalt mindestens 15 Minuten ausspülen. Sofort Augenarzt hinzuziehen.
Nach Einatmen: Frischluft. Sofort Arzt hinzuziehen.
Nach Verschlucken: Speiseessig oder Zitronensaft trinken, dann reichlich Wasser. Erbrechen wegen Perforationsgefahr vermeiden. Sofort Arzt hinzuziehen.
Nach Kleidungskontakt: Kontaminierte Kleidung sofort entfernen.
Ersthelfer: siehe gesonderten Anschlag
Sachgerechte Entsorgung
Aufgeschlämmt in einem trockenem, inerten Lösemittel, z.B. Tetrahydrofuran, tropfenweise mit 2-Propanol versetzten. Nach dem die Reaktion abgeklungen ist, vorsichtig Wasser zugeben. Nach Neutralisation zu den organischen, halogenfreien Lösemittelabfällen geben.
Beschreibung
Sodium hydride, is a binary salt that has a specific hazard of releasing hydrogen upon contact with water. It is an odorless powder that is violently water reactive. The four-digit UN identification number is 1427. The NFPA 704 designation is health 3, flammability 3, and reactivity 2. The white space at the bottom of the diamond has a W with a slash through it, indicating water reactivity.
Chemische Eigenschaften
Grey solid. Pure sodium hydride forms colorless cubic crystals; however, the commercial product contains traces of sodium metal, giving it a light gray color. At atmospheric pressure, sodium hydride slowly evolves hydrogen above 300 ℃. At 420 ℃ decomposition is rapid but melting does not take place. Sodium hydride is a salt and therefore insoluble in inert organic solvents. It dissolves in molten sodium hydroxide, in sodium – potassium alloys and in molten LiCl – KCl eutectic mixtures (352 ℃). Sodium hydride is stable in dry air but ignites above 230 ℃, burning to form sodium oxide. It is hydrolyzed rapidly in moist air and as a dry powder it is spontaneously flammable. Sodium hydride reacts extremely violently with water, the heat of hydrolysis being sufficient to ignite the liberated hydrogen. It reacts with carbon dioxide to form sodium formate.
Physikalische Eigenschaften
Silvery needles; refractive index 1.470; density 0.92 g/cm
3; decomposes at 800°C; decomposes explosively in water; reacts violently with lower alcohols; dissolves in molten sodium and molten sodium hydroxide; insoluble in liquid ammonia, benzene, carbon tetrachloride and carbon disulfide. Sodium hydride is available commercially
as 80 % and 60 % dispersions in mineral oil.
The light-gray pourable material has an average particle size of 10 mm (Degussa, Chemetall, Ventron). The oil protects the surface of
the highly reactive sodium hydride, which easily becomes passivated by the slightest atmospheric exposure or, worse, can ignite on longer
contact with air.
Verwenden
Sodium hydride is used to enhance the condensation reactions of carbonyl compounds through the Dieckmann condensation, Stobbe condensation, Darzens condensation and Claisen condensation. It acts as a reducing agent used to prepare diborane from boron trifluoride. It is also used in fuel cell vehicles. Further, it is used to dry some organic solvents. In addition to this, it is involved in the preparation of sulfur ylides, which is utilized for the conversion of ketones into epoxides.
Vorbereitung Methode
Sodium hydride, reactive with water yielding hydrogen gas and NaOH solution, formed by reaction of sodium and hydrogen at about 360 °C (680 °F). Used as a powerful reducing agent.
Definition
sodium hydride: A white crystallinesolid, NaH; cubic; r.d. 0.92; decomposesabove 300°C (slow);completely decomposed at 800°C.Sodium hydride is prepared by thereaction of pure dry hydrogen withsodium at 350°C. Electrolysis ofsodium hydride in molten LiCl/KClleads to the evolution of hydrogen;this is taken as evidence for the ionicnature of NaH and the presence ofthe hydride ion (H–). It reacts violentlywith water to give sodium hydroxideand hydrogen, with halogensto give the halide and appropriatehydrogen halide, and ignites spontaneouslywith oxygen at 230°C. It is apowerful reducing agent with severallaboratory applications.
Allgemeine Beschreibung
A silvery to whitish powder or slurry in oil. Used to make other chemicals.
Air & Water Reaktionen
Highly flammable. Ignites or explodes in contact with air of high humidity [Bretherick 1979 p. 107]. Reacts violently with water producing a caustic solution (NaOH) and hydrogen (H2). Heat of reaction may ignite the hydrogen.
Reaktivität anzeigen
Sodium hydride is a powerful reducing agent. Attacks SiO2 in glass. Ignites on contact with gaseous F2, Cl2, Br2, and I2 (the last at temperatures exceeding 100°C), especially in the presence of moisture, to form HF, HCl, HBr, and HI [Mellor 2:483 1946-47]. Reacts with sulfur to give Na2S and H2S [Bretherick 1979 p. 107]. Can react explosively with dimethyl sulfoxide [Chem. Eng. News 44(24):7 1966]. Reacts vigorously with acetylene, even at -60°C [Mellor 2:483 1946-47]. Spontaneously flammable in fluorine. Reaction with dimethylformamide, when heated, runs away [Chem. Eng. News, 1982, 60(28), 5]. Initiates a polymerization reaction in ethyl-2,2,3-trifluoropropionate such that the ester decomposed violently [Bretherick 5th ed. 1995]. Presence in the reaction of diethyl succinate and ethyl trifluoroacetate, has twice caused explosions [Chem. Brit., 1983, 19, 645].
Hazard
Dangerous fire risk, reacts violently with
water evolving hydrogen. Irritant.
Health Hazard
SOLID: Will burn skin and eyes. Harmful if swallowed.
Brandgefahr
FLAMMABLE. MAY EXPLODE ON CONTACT WITH WATER. Accidental contact with water used to extinguish surrounding fire will result in the release of hydrogen gas and possible explosion.
Sicherheitsprofil
The powder ignites spontaneously in air. Flammable when exposed to heat or flame. Potentially explosive reaction with water, diethyl succinate + ethyltrifluoroacetate (above 60℃), dimethyl sulfoxide + heat, sulfur dioxide. Ignition or violent reaction with dimethylformamide (above 50℃), ethyl 2,2,3-trifluoropropionate, oxygen (at 230℃). Incompatible with acetylene + moisture, glycerin, halogens, sulphur. Normal fire extinguishers are unsuitable, use sand, ashes, solurn chloride. The commercial material may contain traces of sodium. When heated to decomposition it emits toxic fumes of Na2O. See also HYDRIDES.
Natriumhydrid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
Methyl 3-amino-4-methylthiophene-2-carboxylate
ETHYL 3-AMINOBENZOFURAN-2-CARBOXYLATE
4-(TRIMETHYL-UREIDO)-BENZENESULFONYL CHLORIDE
3-(3,5-DIMETHYL-PYRAZOL-1-YL)-PROPYLAMINE
(6-(1H-Pyrazol-1-yl)pyridin-3-yl)methanol
5-BROMO-2-ETHOXY-PYRIMIDINE
4-Azaoctamethylendiamin
Methyl nicotinoylacetate
5-Fluoro-2-oxindole
3-Amino-2,2-dimethylpropan-1-ol
4-HYDROXY-2-METHYLPYRIMIDINE
4-BROMO-PYRAN-2-ONE
Cyclooctanon
1-Benzyl-2-methyl-1H-imidazol
TEMAFLOXACIN
3,5-Difluorophenylacetic acid
Furo[2,3-b]pyridine-2-carboxylic acid, 3-amino-, ethyl ester (9CI)
2-(TETRAHYDRO-PYRAN-4-YL)-ETHANOL
(Z)-Tetradec-9-enol
1-BOC-4-HYDROXY-4-(HYDROXYMETHYL)-PIPERIDINE
N-(4,6-DIMETHYLPYRIMIDIN-2-YL)-N-METHYLBENZENE-1,4-DIAMINE
1-BENZYL-2-IMIDAZOLECARBOXYLIC ACID
ETHYL 4-METHOXY-3-OXO-BUTANOATE
Sarafloxacin
Methyl 6-(1H-pyrazol-1-yl)pyridine-3-carboxylate
6-(1H-PYRAZOL-1-YL)NICOTINONITRILE
Sertaconazole nitrate
7-METHYL-1,6-OCTADIENE
Ofloxacin
6-(1H-PYRAZOL-1-YL)NICOTINIC ACID
N-METHYL-6-(1H-PYRAZOL-1-YL)NICOTINAMIDE
2 , 4-BIS(BENZYLOXY)-5-BROMOPYRIMIDINE
[3R-(3α,3aβ,6β,7β,8aα)]-Octahydro-6-methoxy-3,6,8,8-tetramethyl-1H-3a,7-methanoazulen
3,5-DIMETHYL-3H-IMIDAZOLE-4-CARBOXYLIC ACID ETHYL ESTER
5-FLUORO-2-METHYLBENZOTHIAZOLE
FLOSEQUINAN
(R)-(-)-Benzyl glycidyl ether
2,4,6-Tris(2-pyridyl)-s-triazin
2,2-DIMETHYLCYCLOHEXANONE
CROCONAZOLE
