7646-69-7 Usage
Chemical Description
Sodium hydride is an inorganic compound with the formula NaH.
Uses
1. Pharmaceutical Industry:
Sodium hydride is used as a condensing agent, an alkylating agent, and a reducing agent for the synthesis of various drugs. It enhances the condensation reactions of carbonyl compounds through the Dieckmann condensation, Stobbe condensation, Darzens condensation, and Claisen condensation.
2. Polymer Industry:
Sodium hydride is used as a polymerization catalyst, contributing to the manufacturing process of different types of polymers.
3. Fragrance Industry:
In the fragrance industry, sodium hydride is used for the synthesis of various compounds that contribute to the scents of perfumes and other fragrance products.
4. Dyes Industry:
Sodium hydride is used as a reducing agent and a drying agent in the production of dyes, aiding in the synthesis of colorants.
5. Fuel Cell Vehicles:
Sodium hydride is utilized in the development of superconducting materials, such as (NaH)4C60, which can be used in fuel cell vehicles.
6. Chemical Synthesis:
Sodium hydride is used in the manufacture of boron hydrides and other chemicals, acting as a reducing agent to prepare diborane from boron trifluoride.
7. Metal Surface Treatment:
Sodium hydride is used in the reduction of oxide scale on metals, improving the surface quality and appearance of metal components.
8. Desiccant:
Due to its ability to react with water, sodium hydride is used as a desiccant to dry organic solvents and other materials.
9. Laboratory Applications:
Sodium hydride is used in various laboratory applications, such as the preparation of sulfur ylides, which are utilized for the conversion of ketones into epoxides.
Physical Properties:
Sodium hydride appears as silvery needles or a whitish powder and is an ionic crystal. It has a refractive index of 1.470 and decomposes explosively in water. It reacts violently with lower alcohols and dissolves in molten sodium and molten sodium hydroxide. Sodium hydride is insoluble in liquid ammonia, benzene, carbon tetrachloride, and carbon disulfide.
Chemical Properties:
Sodium hydride is a grey solid that is unstable when heated, decomposing without melting. It undergoes a hydrolysis reaction with water to produce sodium hydroxide and hydrogen.
Related chemical reaction
Sodium hydride is a strong reducing agent, For example, titanium tetrachloride can reduced to metallic titanium at 400 ℃: TiCl4 == 4NaH + Ti + 4NaCl + 2H2.
At atmospheric pressure and heated to 425 ℃, it decomposes to generate hydrogen gas. And it can violently react with water, even causes a fire, and produces sodium hydroxide and hydrogen. It reacts with liquild ammonia to prepare amine salt (sodium amide) and hydrogen. NaH + NH3-(H2) → NaNH2 + H2.
At a high temperature, sodium hydride also reacts with halogen, sulfur vapor, sulfur dioxide and carbon dioxide. It is highly reductive, liberates the metal from metal oxides, metal chlorides.
TiCl4 + 4NaH → Ti + NaCl + 2H2.
Sodium hydride reacts with boron trifluoride to generate diborane.
2BF3 + 6NaH → B2H6 + 6NaF.
Sodium hydride is stable in dry air below 230 ℃, over this temperature it will burn into sodium oxide. If there is the presence of trace amounts of sodium, even at low temperatures it is also easy to fire. When firing, water and organic fire extinguishing agent must not be used.
Preparation
Sodium hydride is prepared by passing hydrogen gas into molten sodium metal dispersed in oil. Alternatively, the hydride can be made by passing hydrogen into sodium dispersed over the surface of an inert solid, such as, hydrocarbon above 200°C
2Na + H2 → 2NaH
Flammability hazard characteristics
Encountering Water or moist air to emit hydrogen and can be combustible
Storage Characteristics
Treasury ventilation low-temperature drying, stored separately from oxidants, halogens, strong acids.
Production Methods
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.
Air & Water Reactions
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.
Reactivity Profile
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.
Fire Hazard
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.
Flammability and Explosibility
Highlyflammable
Safety Profile
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.
Check Digit Verification of cas no
The CAS Registry Mumber 7646-69-7 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,6,4 and 6 respectively; the second part has 2 digits, 6 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 7646-69:
(6*7)+(5*6)+(4*4)+(3*6)+(2*6)+(1*9)=127
127 % 10 = 7
So 7646-69-7 is a valid CAS Registry Number.
InChI:InChI=1/Na.H/rHNa/h1H
7646-69-7Relevant academic research and scientific papers
Xiong, Zhitao,Wu, Guotao,Hu, Jianjiang,Chen, Ping
, p. 152 - 156 (2007)
Ca-Na-N-H system was introduced and evaluated in this paper for reversible hydrogen storage. Similar to other amide-hydride systems already reported, interaction between Ca(NH2)2-NaH (1/1) was observed in the temperature range of 120
Naik, Mehraj-ud-din,Rather, Sami-ullah,Zacharia, Renju,So, Chang Su,Hwang, Sang Woon,Kim, Ae Rhan,Nahm, Kee Suk
, p. L16-L22 (2009)
A comparative study of the dehydrogenation of pure, ScCl3-, TiCl3-, VCl3-, and MnCl2-doped sodium alanate is reported. The samples wet-doped with transition metal halides exhibit significant lowering of both fir
Kadir,Noréus
, p. 149 - 151 (2009)
NaAl2Ga2 intermetallic compound has been synthesized by direct combination of the elements in the atomic ratio Na:Ga:Al = 1:2:2. Guinier-H?gg X-ray and neutron powder diffraction determined a ThCr2Si2 type struc
Kadir, Karim,Noreus, Dag
, p. 2220 - 2223 (2007)
Mg2Na2NiH6 was synthesized by reacting NaH and Mg2NiH4 at 310°C under hydrogen pressure. The novel structure type was refined from neutron-diffraction data in the orthorhombic space group Pnma (No. 62), with unit cell dimensions of a = 11.428(2), b = 8.442(2), and c = 5.4165(9) A and a unit cell volume = 523 A3 (Z = 4). The structure can be described by (Mg 2H2)2+ layers intersected by (Na 2NiH4)2- layers. The [NiH4] 4- complex is approximately tetrahedral, indicating formal zerovalent nickel. This is the first example of a solid-state hydride where a [NiH 4]4- complex is directly stabilized by alkali metal ions instead of the more polarizing Mg2+ ions. A rather long nickel-hydrogen bond distance of 1.65 A indicates a weaker Ni-H bond as a result of the weaker support from the less polarizing alkali metal counterions.
Bronger, W.,Gehlen, M.,Auffermann, G.
, p. 255 - 262 (1991)
The ternary alkali metal rhodium and iridium hydrides were synthesized by the reaction of alkali metal hydride with transition metal powder in a pure hydrogen atmosphere. The crystal structures were determined by X-ray investigations on powdered samples and elastic neutron diffraction experiments on the deuterated compounds. The isotypic atomic arrangements (space group Pnma) contain isolated [RhH6]3-- and [IrH6]3--octahedra which are separated by the alkali metal ions.
Sastry, K. V. L. N.,Herbst, Eric,Lucia, Frank C. De
, p. 4753 - 4757 (1981)
Utilizing a glow discharge absorption cell, we have detected the v = 0, 1, 2, and 3, J = 0 -> 1 transitions of NaH and the v = 0, 1, 2, and 3, J = 1 -> 2 and v = 0, J = 2 -> 3 transitions of NaD in the millimeter and submillimeter regions of the spectrum.The derived Dunham constants (MHz) are .A significant breakdown of the Born-Oppenheimer approximation has been observed.
Elansari,Antoine,Janot,Gachon,Kuntz,Guérard
, p. L5-L8 (2001)
Rubidium and cesium hydrides are not commercialized and we have set up, a few years ago, a method of synthesis at the laboratory scale. It is based on the reaction of alkali metal with hydrogen obtained by thermal decomposition of uranium hydride UH3 at a temperature of 450°C, which gives a pressure of hydrogen close to 3 bars. This synthesis leads to a very pure alkali metal hydride MH, but the rate of the reaction remains quite small: a few hundreds of milligrams in 24 h. A new method, based on mechanical alloying, consists in milling the alkali metal, at room temperature, under a pressure of hydrogen close to 5 bars. The reaction proceeds in 16 h and gives 3-15 g of very pure MH (from sodium to cesium, respectively) at once.
Noreus,Tornroos,Borje,Szabo
, p. 233 - 239 (1988)
The ternary hydride Na//2PdH//2 was synthesized by the reaction of sodium hydride with palladium in a hydrogen atmosphere at 370 degree C. The structure was derived from X-ray investigations on powdered samples and on a single crystal as well as from neutron diffraction experiments on the deuterated compound. Na//2PdH//2 crystallizes in the tetragonal space group I4/mmm and is isotypic with Na//2HgO//2. The atomic arrangement is characterized by a novel linear left bracket PdH//2 right bracket complex.
Yabuzaki, T.,Sato, T.,Ogawa, T.
, p. 2780 - 2783 (1980)
Production of NaH crystalline particles of μm size is observed in sodium vapor mixed with ca. 10 Torr H2.The particles are produced when Na2 is excited to the B 1Πu state by a cw Ar+ laser, and also when Na is excited by a cw dye laser tuned to the D1 or D2 line.
Dolotko, Oleksandr,Zhang, Haiqiao,Li, Sa,Jena, Puru,Pecharsky, Vitalij
, p. 224 - 230 (2010)
Mechanochemical transformations of lithium and sodium amides with calcium hydride have been investigated using gas volumetric analysis, X-ray powder diffraction, and residual gas analysis. The overall mechanochemical transformations are equimolar, and the
