Among the following, the molecule expected to be stabilized by anion formation is : `C_(2), O_(2), NO, F_(2)`

Options

A. `C_(2)`
B. `F_(2)`
C. `NO`
D. `O_(2)`

Answer

A

Explanation

Configuration of `C_(2)`
`=sigma1s^(2)sigma^(**)1s^(2)sigma2s^(2)sigma^(**)2s^(2)pi2p_(x)^(2)=pi2p_(y)^(2)`
Configuration of `C_(2)^(-)`
`=sigma1s^(2)sigma^(**)1s^(2)sigma2s^(2)sigma^(**)2s^(2)pi2p_(x)^(2)=pi2p_(y)^(2)sigma2p_(z)^(1)`
Bond order
`=("No. of bonding e"^(-)-"No. of antibonding e"^(-))/(2)`
`C_(2)` has s-p mixing and the HOMO is `pi2p_(x)=pi2p_(y)` and LUMO is `sigma2p_(z)`. So, the extra electron will occupy bonding molecular orbital and this will lead to an increase in bond order.
`C_(2)^(-)` has more bond order than `C_(2)`.