Question

What are electron deficient compounds? Are ${\mathrm{SiCl}}_4$ and ${\mathrm{BCl}}_3$ electron-deficient species. Explain

Answer 1

Electron deficient compounds:

• The compounds in which the central atom does not have eight electrons in its valence shell but can expand the valency due to the presence of vacant d – orbitals.
• In electron-deficient compounds, the central atom lack enough electrons to fulfill its octet.
• This compound behaves as a Lewis acid.

Examples:

• Electron-deficient compounds are those with less than $8$ electrons in their valence shells, such as${\mathrm{BF}}_3,{\mathrm{AlCl}}_3$, and others.

${\mathrm{SiCl}}_4$ as electron-deficient compound:

• The core Si atom possesses $8$ electrons,
• As a result, it is not an electron-deficient molecule.
• 

. ${\mathrm{BCl}}_3$as electron-deficient compound:

• Because boron has three valence electrons, it forms three single bonds with chlorine, producing the boron atom with six electrons in the outermost shell.
• It has still missing two electrons to complete its octet.
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