Diborane

Diborane, with the molecular formula B₂H₆, is a chemical compound consisting of two boron atoms and six hydrogen atoms. It is a colorless, extremely flammable gas with an offensive stench. Diborane has a special structure that forms a “dumbbell” shape with four hydrogen atoms bridging the two boron atoms at the ends.

In this article, we will learn about Structure of Diborane, Formula of Diborane, Properties of Diborane, and others in detail.

Diborane Formula

Two boron and six hydrogen atoms make up the chemical compound diborane, which has the formula B₂H₆

Diborane
IUPAC Name	Boro Ethane
Molecular Formula	B2H6
Molecular Weight	27.67 g/mol
Physical State	Colorless at Room Temperature
Smell	Sweet Smell
Boiling Point	180 K

Structure of Diborane B₂H₆

Diborane has a unique molecular structure that is shaped like a “dumbbell.” With two boron atoms at each end and four hydrogen atoms bridging together, this arrangement contributes particular geometric properties. Four equivalent sp³ hybrid orbitals are formed when the boron atoms go through sp3 hybridization. These orbitals are essential for bonding with the nearby hydrogen atoms.

Physical Properties of Diborane

Composed of hydrogen and boron, diborane has the chemical formula B2H6. Because of its intriguing structure and distinct physical characteristics, it is a noteworthy chemical. Diborane has the following important physical characteristics:

• Conditions at Room Temperature: Diborane is a colorless gas at room temperature.

• Odor: It smells strong and somewhat sweet.

• Densities: With a density of around 1.1 kg/m³, diborane is less dense than air.

• Boiling Point: At normal temperatures and pressures, diborane occurs as a gas, hence it is neither a conventional solid nor liquid at regular atmospheric pressure. It has a boiling point of about 180 K

• Solubility: Diborane dissolves in water very little. When it interacts with water, it breaks down into hydrogen and boric acid.

• Flammability: Diborane is extremely flammable and may catch fire on its own when oxygen or air are present.

• Reaction: Diborane interacts violently with oxidizing agents and is a potent reducing agent.

• Toxicity: Diborane is hazardous and should be handled carefully since it can catch fire and pose health risks.

• Solubility: Diborane only partially dissolves in water. When it interacts with water, hydrogen and boric acid are produced.

Chemical Properties of Diborane

Chemical properties of Diborane includes,

Reactivity

Diborane’s high reactivity is mostly caused by the boron-hydrogen bonds that it contains. Because of these bonds’ easy engagement in a variety of chemical reactions, diborane is a compound that is useful in synthesis processes.

Combustibility

Diborane burns rapidly and produces interesting combustion reactions. For example, burning boron hydrides, such as the reaction between boron trichloride and lithium aluminum hydride, is a typical technique for preparing diborane:

6BCl₃ + 6LiAlH₄ → 2B₂H₆ + 6LiCl + 6AlCl₃​

Diborane has a low boiling point and is volatile, which contributes to its gaseous form at room temperature and pressure.

Stability

Diborane is stable when maintained in carefully monitored environments, despite its reactivity. On the other hand, the chemical is susceptible to spontaneous breakdown due to its sensitivity to heat, light, and certain catalysts.

Production of Diborane

Industrial preparation of diborane (B₂H₆) involves a few key techniques that take use of boron hydride reactivity. Combustion of boron hydrides, such as the reaction between lithium aluminum hydride (LiAlH₄) and boron trichloride (BCl₃), is one noteworthy method.

Following is a representation of the combustion reaction:

B₂H₆ + 6LiCl + 6AlCl₃ → 6BCl₃ + 6LiAlH₄

Lithium aluminum hydride and boron trichloride react in this procedure, producing diborane, lithium chloride, and aluminum chloride as byproducts. The reaction mixture is then separated from diborane.

Another technique uses lithium aluminum hydride to reduce boron trifluoride:

B₂H₆ + 6LiF + 6AlH₃ → 2BF₃ + 6LiAlH₄

Diborane, lithium fluoride, and aluminum hydride are the products of this reaction between boron trifluoride and lithium aluminum hydride.

These processes produce diborane by taking advantage of lithium aluminum hydride’s reductive properties. Given that diborane is flammable and reactive, it is imperative that these reactions be carried out under carefully monitored circumstances. After that, diborane can be extracted and used for a number of processes, such as semiconductor manufacturing and catalysis.

Reactions of Diborane

Various reactions of Diborane includes,

Reaction with Water

When diborane and water react violently, hydrogen gas and boric acid are produced:

B₂H₆ + 6H₂O → 2H₃BO₃ + 6H₂

Reaction with Air

When diborane and air combine violently, boron oxide (B₂O₃) and water are produced by combustion.

B₂H₆ + 3O₂ → B₂O₃ + 3H₂O

Reaction with Alkali Action

Hydrogen gas and borates are produced when diborane combines with alkali solutions, such as sodium hydroxide, or NaOH.

B₂H₆ + 6NaOH → 2B(OH)₃ + 6H₂

Hydroboration

Diborane is frequently added to unsaturated organic compounds such as alkenes or alkynes in hydroboration processes. Diborane’s hydrogen and boron contribute across the double or triple bond:

B₂H₆ + H₂C = CH₂ → H₃B-CH₂-CH₂-BH₃

Reaction with Ionic Hydrides

Bobon hydrides are created when diborane combines with ionic hydrides, or substances that contain H^- ions. Lithium hydride (LiH), for instance:

B₂H₆ + 2LiH → 2LiBH₄

Reaction with Ammonia

Ammonia (NH₃) and diborane combine to create amino borane complexes.

B₂H₆ + 2NH₃ → 2H₃BNH₃

Application of Diborane

Some applications of Diborane are,

• Diborane in organic synthesis, serves as a reducing agent.
• Diborane is used in semiconductor manufacturing.
• Diborane is an important constituent in making of Borophosphosilicate a type of glass.
• It is used as rocket fuel.
• Diborane is a reducing agent in various chemical reaction.

Health Consequences of Diborane

Health risks associated with diborane (B₂H₆) are mostly caused by inhalation or direct contact. Exposure can cause irritation of the eyes and respiratory tract, which can result in symptoms like coughing and eye pain. Extended exposure can lead to long-term respiratory problems, which highlights the significance of safety precautions.

Preventive Actions

• Protective Equipment: When handling diborane, wear eye and respiratory protection.
• Ventilation: Make sure there is enough ventilation to reduce the risk of inhalation.
• Limit Exposure: To avoid extended contact, impose stringent exposure limits.

Emergency Responses for Use of Diborane

• Give instruction on emergency response protocols.
• Promote awareness in order to reduce unintentional exposures.

Diborane-FAQs

1. Why is Banana Bond Formed in Diborane?

Banana bonds is formed when three atoms and one electron from Hydrogen and other from Boron, two electrons forms a type bond.

2. What is the Name for B₂H₆?

The name of B₂H₆ is Diborane.

3. What are Applications of Diborane?

Diborane (B₂H₆) is used in,

• Vulcanization of Rubber
• Used as Rocket Fuel, etc.

4. What is Bridge Bonding in B₂H₆?

Bridge bonding is a special type bond that take place in formation of Diborane.

5. How Safe is it to keep Diborane?

Diborane is highly reactive, which makes storage challenging. To lessen the dangers associated with storage, it is often handled with specialist equipment and utilized as soon as feasible.

6. What Environmental Issues are Associated with Diborane?

Diborane should be released into the environment as little as possible since it may be detrimental to both human health and the ecology. Diborane has the potential to pollute the air.

7. How is Diborane made in a Lab?

Boron Trifluoride (BF₃) and Sodium Borohydride (NaBH₄) or Lithium Aluminum Hydroxide (LiAlH₄) reacts to form Diborane.

8. How Does Water and Diborane React with Each Other?

Water and diborane react strongly to generate hydrogen gas and Boric Acid (H₃BO₃). This process is exothermic, meaning it generates a lot of heat.