Assertion: Zero and negative oxidation state of d-block metal ion are not possible in their complex compound. Reason: Low oxidation state of the metal ions are found when a complex compound has ligands capable of pi-aceptor character in addition to the sigma- bonding.

Assertion: Zero and negative oxidation state of d-block metal ion are

1.	Assertion: Zero and negative oxidation state of d-block metal ion are not possible in their complex compound. Reason: Low oxidation state of the metal ions are found when a complex compound has ligands capable of pi-aceptor character in addition to the sigma- bonding.
Answer» If both assertion and reason are true and the reason is the correct EXPLANATION of assertion If both assertion and reason are true and the reason is not the correct explanation of assertion If assertion is false but reason is true If assertion is true but the reason is false Solution :In case of `pi`-acceptor ligands (like CO, NO) ZERO and negative oxidation state of d-block metal ion is possible DUE to phenomenon of Synergic BONDING.