MCQ Detailed View

Diborane (B₂H₆) is a well-known example of an electron-deficient compound in inorganic chemistry. The molecule consists of two boron atoms bonded to six hydrogen atoms, forming a unique structure with three-center two-electron (3c-2e) bonds, also called banana bonds.

In B₂H₆, each boron atom is bonded to two terminal hydrogen atoms and shares two bridging hydrogen atoms with the other boron. To explain this bonding arrangement, boron undergoes sp hybridization. Each boron atom mixes its one 2s and one 2p orbital to form two sp hybrid orbitals. One sp orbital forms a sigma bond with a terminal hydrogen, while the other forms a banana bond with a bridging hydrogen, linking the two boron atoms.

The remaining two unhybridized 2p orbitals on each boron are involved in delocalized bonding, contributing to the stability of the bridging bonds. This hybridization explains the linear arrangement of B–H–B bridges and the 120° bond angles around the boron atoms.

Other hybridizations, such as sp² or sp³, do not explain the formation of the three-center two-electron bonds in diborane. Sp³d² hybridization is relevant only in molecules with expanded octets, which is not the case here.

Understanding the sp hybridization of boron in B₂H₆ is crucial in inorganic chemistry as it helps explain electron-deficient compounds, bonding theories, and molecular structure. The concept is widely applied in studying boranes, cluster compounds, and coordination chemistry. Recognizing sp hybridization in diborane also introduces students to advanced bonding concepts beyond simple octet theory.