Diboran

Diboran
Diboran
Are common
Systematic ; name	diborane
Chem. formula	B 2 H 6
Physical properties
condition	gas
Impurities	Pentaborane
Molar mass	27.67 g / mol
Density	0.447 (–112 ° C)
Ionization energy
Thermal properties
T. melt.	−165.5 ° C
T. bale.	−92.4 ° C
Etc. blast
Like heat resistant.	298 K J / (mol · K)
Steam pressure
Classification
Reg. CAS number	19287-45-7
Reg. EINECS number
Smiles
Inchi
RTECS
Chebi
ChemSpider
Security
LD 50	40 mg / m3 (rat, 4 hours); 29 mg / m3 (mouse, 4 hours); 159-181 mg / m3 (rat, 15 minutes)
Toxicity	very toxic
GHS icons
NFPA 704	four four four W

Diborane is a chemical compound of hydrogen and boron with the formula B ₂ H ₆ . It was first synthesized in the 19th century. It is a colorless gas with a sweet smell. Diboran is a very toxic boron hydrogen. In contact with air, it can ignite spontaneously.

Content

Getting

Existing methods for producing diborane are based on the interaction of boron halides or alkoxides with hydride ion donors.

In industry, diborane is obtained by reducing BF ₃ :

{\mathsf {2BF_{3}+6NaH\longrightarrow B_{2}H_{6}+6NaF}}

{\ displaystyle {\ mathsf {2BF_ {3} + 6NaH \ longrightarrow B_ {2} H_ {6} + 6NaF}}}

Upon receipt of diboran in laboratory conditions, fluoride or boron chloride is reduced:

{\mathsf {4BCl_{3}+3LiAlH_{4}\longrightarrow 2B_{2}H_{6}+3LiAlCl_{4}}}

{\ displaystyle {\ mathsf {4BCl_ {3} + 3LiAlH_ {4} \ longrightarrow 2B_ {2} H_ {6} + 3LiAlCl_ {4}}}}

{\mathsf {4BF_{3}+3NaBH_{4}\longrightarrow 2B_{2}H_{6}+3NaBF_{4}}}

{\ displaystyle {\ mathsf {4BF_ {3} + 3NaBH_ {4} \ longrightarrow 2B_ {2} H_ {6} + 3NaBF_ {4}}}}

Chemical Properties

Diboran is a strong Lewis acid , as it is able to form complexes with bases (for example, with ammonia ).

Diborane interacts with water. In this case, hydrogen is released and boric acid is formed :

{\mathsf {B_{2}H_{6}+6H_{2}O\longrightarrow 2H_{3}BO_{3}+6H_{2}}}

{\ displaystyle {\ mathsf {B_ {2} H_ {6} + 6H_ {2} O \ longrightarrow 2H_ {3} BO_ {3} + 6H_ {2}}}}

.

Slowly reacts with aluminum hydride to form ( aluminum tetrahydride borate), which allows you to pack it into crystals to produce hydrogen:

${\mathsf {2AlH_{3}+B_{2}H_{6}\ {\xrightarrow {\ }}2Al(BH_{4})_{3}}}$ ${\ displaystyle {\ mathsf {2AlH_ {3} + B_ {2} H_ {6} \ {\ xrightarrow {\}} 2Al (BH_ {4}) _ {3}}}}$ but these crystals decompose with the release of diborane at 70 degrees,

and with the formation of octadecaborate (III) aluminum , and the liberated diborane is poisonous.

Application

Hydrogen boron derivatives are used as antioxidants, catalysts for the oxidation of saturated and aromatic hydrocarbons to alcohols and phenols , and additives to lubricating oils.

Notes

↑ ¹ ² ³ http://www.cdc.gov/niosh/npg/npgd0183.html

Links

[_7aa960b1b4ec3b58-1] ¹ ² ³ http://www.cdc.gov/niosh/npg/npgd0183.html