Sodium borohydride
General
Systematic name	Sodium tetrahydroborate
Molecular formula	NaBH4
Molar mass	37.83 g/mol
Appearance1.0740	white solid
CAS number	[16940-66-2]
Melting point	36 °C
Boiling point	400 °C (dec.)
Decomposition temperature	>400 °C (dec.)
Density	1.0740 g cm-3
Solvents	diglyme (51.5 g/L) alkaline MeOH (130 g/L)
NFPA 704	1 2 2 W
Related compounds
Other anions	Sodium cyanoborohydride Sodium hydride Sodium borate Borax
Other cations	Lithium borohydride
Related compounds	Lithium aluminium hydride
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Sodium borohydride, also known as sodium tetrahydroborate, has the chemical formula NaBH₄. It is a selective specialty reducing agent used in the manufacture of pharmaceuticals and other organic compounds. It is a white solid, usually encountered as a powder. It is soluble in methanol and water, but reacts with both unless strong base is added.^[1] Image File history File links Download high-resolution version (1532x913, 10 KB) Description: Chemical structure of sodium borohydride. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... This article or section does not cite any references or sources. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... The Decomposition Temperature of a substance is the temperature at which the substance decomposes into smaller substances or into its constituent atoms. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is... A substance is soluble in a fluid if it dissolves in the fluid. ... Diglyme, or bis(2-methoxyethyl) ether, is a high boiling solvent. ... NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. ... Image File history File links NFPA_704. ... An electrostatic potential map of the nitrate ion (NO3−). Areas coloured red are lower in energy than areas colored yellow An ion is an atom or group of atoms which have lost or gained one or more electrons, making them negatively or positively charged. ... Sodium cyanoborohydride (NaBH3(CN) is a chemical compound. ... Sodium hydride is a highly flammable, and corrosive chemical compound with formula NaH and CAS number 7646-69-7. ... Borax, (Na2B4O7·10H2O, sodium borate or sodium tetraborate) is an important boron compound. ... Borax from Persian burah. ... An electrostatic potential map of the nitrate ion (NO3−). Areas coloured red are lower in energy than areas colored yellow An ion is an atom or group of atoms which have lost or gained one or more electrons, making them negatively or positively charged. ... Lithium Borohydride is known in organic synthesis as a reducing agent for Esters. ... Lithium aluminium hydride (LiAlH4), commonly abbreviated to LAH, is a powerful reducing agent used in organic chemistry. ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... This article or section does not cite any references or sources. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Standard atomic weight 22. ... General Name, Symbol, Number boron, B, 5 Chemical series metalloids Group, Period, Block 13, 2, p Appearance black/brown Standard atomic weight 10. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... A reducing agent (also called a reductant or reducer) is the element or a compound in a redox (reduction-oxidation) reaction (see electrochemistry) that reduces another species. ... Pharmacology (in Greek: pharmakos (φάρμακον) meaning drug, and logos (λόγος) meaning science) is the study of how substances interact with living organisms to produce a change in function. ... It has been suggested that this article or section be merged with Solution. ...

The compound was discovered in the 1940's by H. I. Schlessinger, who led a team that developed metal borohydrides for wartime applications.^[2] Hermann Irving Schlesinger (October 11, 1882 - October 3, 1960) was an American inorganic chemist, working in boron chemistry. ...

Synthesis and handling

Sodium borohydride is prepared by the reaction of sodium hydride on trimethylborate at 250-270°C: Sodium hydride is a highly flammable, and corrosive chemical compound with formula NaH and CAS number 7646-69-7. ... Trimethyl borate, or boron trimethoxide, has formula B(OCH3)3. ...

B(OCH₃)₃ + 4 NaH → NaBH₄ + 3 NaOCH₃

It can also be generated by the action of NaH on powdered borosilicate glass.^[3] It has been suggested that Kimax be merged into this article or section. ...

NaBH₄ can be recrystallized by dissolving in warm (50 °C) diglyme followed by cooling the solution.^[4] Diglyme, or bis(2-methoxyethyl) ether, is a high boiling solvent. ...

Reactivity

Organic synthetic applications

Sodium borohydride reduce aldehydes and ketones into alcohols, but unlike the powerful reducing agent lithium aluminium hydride, NaBH₄ will generally not reduce esters, amides, or carboxylic acids.^[5]. An example of the use of sodium borohydride is the industrial production of fexofenadine which includes a reduction step ^[6]: Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. ... An aldehyde. ... Ketone group A ketone(key tone) is either the functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms or a chemical compound that contains this functional group. ... Functional group of an alcohol molecule. ... Lithium aluminium hydride (LiAlH4), commonly abbreviated to LAH, is a powerful reducing agent used in organic chemistry. ... A carboxylic acid ester. ... Amide functional group Amides possess a conjugated system spread over the O, C and N atoms, consisting of molecular orbitals occupied by delocalized electrons. ... Structure of a carboxylic acid The 3D structure of the carboxyl group A space-filling model of the carboxyl group Carboxylic acids are organic acids characterized by the presence of a carboxyl group, which has the formula -C(=O)OH, usually written -COOH or -CO2H. [1] Carboxylic acids are Bronsted... Fexofenadine hydrochloride (brand names include Allegra® and Telfast®) is an antihistamine drug used in the treatment of hayfever and similar allergy symptoms. ...

In general the reactivity of boron hydrides can be modified by seeming subtle changes in its structure. For example, sodium cyanoborohydride (NaCNBH₃) converts certain alcohol groups to methylene groups. The reagent known as L-Selectride, lithium tri-sec-butylborohydride), is a still more powerful reducing agent.^[7]. Another modification is sodium triacetoxyborohydride (NaBH(OCOCH₃)₃). Image File history File links Download high-resolution version (1053x756, 12 KB) Fexofenadine Synthesis I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Sodium cyanoborohydride (NaBH3(CN) is a chemical compound. ... Functional group of an alcohol molecule. ... In chemistry, methylene is a divalent functional group CH2 derived formally from methane. ...

Other reactions

Oxidation of NaBH₄ with iodine in tetrahydrofuran creates the BH₃-THF complex which can reduce esters. Likewise the NaBH₄-MeOH system, formed by the addition of methanol to sodium borohydride in refluxing THF reduces esters to the corresponding alcohols for instance benzyl benzoate to benzyl alcohol.^[8] General Name, Symbol, Number iodine, I, 53 Chemical series halogens Group, Period, Block 17, 5, p Appearance violet-dark gray, lustrous Standard atomic weight 126. ... For other uses of THF, see THF (disambiguation) Tetrahydrofuran is a heterocyclic organic compound. ... Diborane is a colorless gas at room temperature with a repulsive, sweet odor. ... For other uses of THF, see THF (disambiguation) Tetrahydrofuran is a heterocyclic organic compound. ... Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naptha or wood spirits, is a chemical compound with chemical formula CH3OH. It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid with a distinctive odor that is somewhat milder and sweeter than ethanol (ethyl alcohol). ... This page may meet Wikipedias criteria for speedy deletion. ... Benzyl alcohol, also known as phenylmethanol, is a clear, colorless liquid with a mild pleasant aromatic odor. ...

BH₄^- is an excellent ligand for metal ions. Such borohydride complexes are often prepared by the action of NaBH₄ (or the LiBH₄) on the corresponding metal halide, e.g. Zr(BH₄)₄. In chemistry, a ligand is an atom, ion, or molecule (see also: functional group) that generally donates one or more of its electrons through a coordinate covalent bond to, or shares its electrons through a covalent bond with, one or more central atoms or ions (these ligands act as a...

Fuel cells

For more details on this topic, see Direct borohydride fuel cell.

Sodium borohydride is also used in experimental fuel cell systems as a means of storing hydrogen. As a fuel it is less flammable and less volatile than gasoline but more corrosive. It is relatively environmentally friendly because it will quickly degrade into inert salts when released into the environment. The hydrogen is generated for a fuel cell by catalytic decomposition of the aqueous borohydride solution: Direct Borohydride Fuel Cell or DBFCs are a subcategory of Proton-exchange fuel cells where the fuel is a solution of Sodium borohydride. ... A fuel cell is an electrochemical device similar to a battery, but differing from the latter in that it is designed for continuous replenishment of the reactants consumed; i. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Gasoline, as it is known in North America, or petrol, in many Commonwealth countries (sometimes also called motor spirit) is a petroleum-derived liquid mixture consisting primarily of hydrocarbons, used as fuel in internal combustion engines. ... It has been suggested that this article or section be merged into Catalysis. ...

NaBH₄ + 2H₂O → NaBO₂ + 4H₂

Safety

Decomposes to borane and hydrogen rapidly upon acidification. Flammable. A borane is an inorganic chemical compound of boron and hydrogen. ...

References

Herbert Charles Brown (May 22, 1912 – December 19, 2004) was a chemist who won the Nobel Prize in Chemistry in 1979 (along with Georg Wittig) for his work with organoboranes. ... The Journal of the American Chemical Society (usually abbreviated as , or JACS), is a peer-reviewed scientific journal, published since 1879 by the American Chemical Society. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Arkivoc stands for Archive for Organic Chemistry and is an online open access scientific journal of Organic Chemistry. ... For the Manfred Mann album, see 2006 (album). ... is the 241st day of the year (242nd in leap years) in the Gregorian calendar. ...

External links

• Material Safety Data Sheet
• National Pollutant Inventory - Boron and compounds
• Hydrogen Storage via Sodium Borohydride, Millennium Cell inc. (PDF)
• Materials & Energy Research Institute Tokyo, Ltd.
• Chemo- and stereoselectivity using Borohydride reagents
• Links to external chemical sources