Hybridisation of BCl₃

Boron trichloride (BCl₃) is a chemical compound composed of one boron atom and three chlorine atoms. It is a colorless gas with a pungent odor and is commonly used in the electronics industry, particularly in semiconductor manufacturing. In this article we will understand what is the hybridization of BCl₃ and other molecular properties of BCl₃.

1.0What is Hybridisation of BCl₃

Let’s learn hybridization in Boron Trichloride (BCl₃) in detail :

The hybridization of an atom refers to the process of combining its atomic orbitals to form new hybrid orbitals that are suitable for bonding. Let’s understand how we can understand sp² hybridization of BCl₃:

• Atomic Orbitals Involved:
• • Boron (B) has an electron configuration of 1s² 2s² 2p¹. It undergoes hybridization to form three equivalent sp² hybrid orbitals.
  • Each chlorine (Cl) atom contributes one unhybridized 3p orbital.
• Hybridization of B in BCl₃:
• • Boron's 2s orbital and two 2p orbitals undergo hybridization to produce three sp² hybrid orbitals.
  • These sp² hybrid orbitals are arranged in a trigonal planar geometry around the boron atom.
• Bonding in BCl₃:
• • Each of the three sp² hybrid orbitals on boron overlaps with a 3p orbital on a chlorine atom, forming three sigma (σ) bonds.
  • The resulting molecule has a trigonal planar shape with bond angles of approximately 120 degrees.

2.0Important Properties of BCl₃

BCl₃ is used as a reagent in various chemical reactions and serves as a precursor in the production of boron-containing compounds. 

Its application extends to areas such as etching processes and the synthesis of organic and inorganic substances. The compound's distinctive properties make it valuable in different industrial contexts.

3.0Physical Properties of BCl₃

4.0Bonding in Boron Trichloride (BCl₃)

Boron trichloride (BCl₃) is a covalent compound, and its bonding involves the sharing of electrons between boron and chlorine atoms.

Number of Valence Electrons: Boron has three valence electrons, and each chlorine atom contributes one electron, resulting in a total of six valence electrons.

Lewis Structure: The Lewis structure of BCl₃ shows three single bonds between boron and chlorine atoms.

Formal Charges: In the Lewis structure, boron carries a formal charge of +1, and each chlorine atom carries a formal charge of -1.

Electron Configuration: The electron configuration of BCl₃ involves the use of three orbitals on boron (2s and two 2p orbitals) for bonding with three singly occupied chlorine 3p orbitals.

5.0Geometry of BCl₃

The molecule adopts a trigonal planar geometry. The three chlorine atoms are arranged symmetrically around the boron atom, with bond angles of approximately 120 degrees. The absence of a lone pair on boron contributes to this geometry. The trigonal planar shape is consistent with the valence shell electron pair repulsion (VSEPR) theory.