Question

 Diborane has

(a) 2 two - centre -two - electron bonds and 4 three - centre - three - electron bonds.

(b) 4 two - centre - two - electron bonds and 2 three - centre - three - electron bonds

(c) 3 two - centre - two - electron bonds and 3 three - centre - three - electron bonds.

(d) all six identical bonds.

Answer 1

Correct option (b) 4 two - centre - two - electron bonds and 2 three - centre - three - electron bonds

Explanation:

Structure of B₂H₆ is as follows:

Thus the diborane molecule has four two-centre-twoelectron bonds (2c–2e bonds) also called usual bonds and two three-centre-two-electron bonds (3c–2e) also called banana bonds. Hydrogen attached to usual and banana bonds are called H_t (terminal H) and H_b (bridged H) respectively.