Question

$B-H-B$ bridge in $B_2{H}_6$ is formed by the involvement of:

• A. 2 electrons
• B. 4 electrons
• C. 1 electrons
• D. 3 electorns

Answer 1

The correct option is A 2 electrons

The structure of diborane is shown in fig. The four terminal hydrogen atoms and the two boron atoms lie in one plane. Above and below this plane, there are two bridging hydrogen atoms. The four terminal B-H bonds are regular two centre-two electron bonds while the two bridge $(B-H-B)$ bonds are different and can be described in terms of $3C-2e^{-}$ bonds.