Which of the following hydrides is electron deficient ?

Options

A. `B_(2)H_(6)`
B. `C_(2)H_(6)`
C. `PH_(3)`
D. `SiH_(4)`

Answer

A

Explanation

`B_(2)H_(6)` is electrons deficient molecule because boron atom has thre half-flled orbits in excited state. The structure of `B_(2)H_(6)` is represented as follows.

In it two electrons of a B-H bond are involved in formation of three centre bond, these bonds are represented as dotted lines.