Question

Select correct statement about $B_2{H}_6$-

• A. Bridging groups are electron-deficient with 12 valence electrons
• B. It has $2c-2e$ $B-H$ bonds
• C. It has $3c-2e$ $B-H-B$ bonds
• D. All the above are correct statements

Answer 1

Answer: (B), (C)

The correct options are
B It has $3c-2e$ $B-H-B$ bonds
C It has $2c-2e$ $B-H$ bonds

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 three centre - two e bonds.