Assertion A : In the complex Ni(CO)4 and Fe(CO)5, the metals have zero oxidation state.Reason R : Low oxidation states are found when a complex has ligands capable of π-donor character in addition to the σ-bonding.In the light of the above statements, choose the most appropriate answer from the options given belowA is correct but R is not correctA is not correct but R is correctBoth A and R are correct but R is NOT the correct explanation of ABoth A and R are correct and R is the correct explanation of A

Both A and R are correct but R is NOT the correct explanation of A.

Explanation: Assertion A is correct. In Ni(CO)4 and Fe(CO)5, the metals Ni and Fe are indeed in the zero oxidation state. This is because CO is a neutral ligand and does not alter the oxidation state of the metal.

Reason R is also correct as a general statement. Low oxidation states are indeed found when a complex has ligands capable of π-donor character in addition to the σ-bonding. However, this is not the reason why Ni and Fe are in the zero oxidation state in Ni(CO)4 and Fe(CO)5. The zero oxidation state is due to the fact that CO is a neutral ligand, not because of its π-donor character. Therefore, R is not the correct explanation of A.