Question

Among the following ions the $p\pi -d\pi$ overlap could be present in:

• A. ${NO}_2^{-}$
• B. ${NO}_3^{-}$
• C. ${PO}_4^{3-}$
• D. ${CO}_3^{2-}$

Answer 1

Answer: (C)

${PO}_4^{3-}$

In $P=O$ bond, $\pi$ - bond is formed by the sidewise overlapping of $d$ - orbital of $P$ and $p$ - orbital of oxygen. Hence, it is formed by $p\pi$ and $d\pi$ overlapping.

In nitrogen and carbon, no vacant $d$-orbital is present. So, they do not form $p\pi -d\pi$ bond.