Which of the following carbonyls will have the strongest C-O bond

Options

A. `Mn(CO)_(6)^(+)`
B. `Cr(CO)_(6)`
C. `V(CO)_(6)^(-)`
D. `Fe(CO)_(5)`

Answer

A

Explanation

As positive charge on the central metal atom increases, the metal shows lesser tendency to donate its electron density to the antibonding `pi` orbitals of CO ligand. This causes strengthening of the C-O bond. Hence, CO bond would be strongest in `Mn(CO)_(6)^(+)`.