Question

Identify the coordination complexes in which the central metal ion has a \(d^4\) configuration.

Choose the correct answer from the options given below :

• A. \= \text{[FeO}_4^{2-}\text{]} \hspace{1cm} \= (I) \hspace{2cm} \= \text{No}
• B. \= \text{[Mn(CN)_6]^{3-}} \hspace{1cm} \= (II) \hspace{2cm} \= \text{Yes}
• C. \= \text{[Fe(CN)_6]^{3-}} \hspace{1cm} \= (III) \hspace{2cm} \= \text{Yes}
• D. \= \text{[Cr}_2(\text{O}-\text{C}-\text{Me})_4(\text{H}_2\text{O})_2\text{O}] \hspace{1cm} \= (IV) \hspace{2cm} \= \text{No}

Hint:

A \(d^4\) configuration typically arises in transition metal complexes like those involving Mn, Fe, and Cr in certain oxidation states.

Answer 1

The Correct Option is C

(A): \( \text{[FeO}_4^{2-} \text{]} \) does not have a \( d^4 \) configuration.
- (B): \( \text{[Mn(CN)_6]^{3-}} \) has a \( d^4 \) configuration.
- (C): \( \text{[Fe(CN)_6]^{3-}} \) also has a \( d^4 \) configuration.
- (D): \( \text{[Cr}_2(\text{O}-\text{C}-\text{Me})_4(\text{H}_2\text{O})_2\text{O]} \) has a \( d^4 \) configuration.
- (E): \( \text{[NiF}_6^{2-} \text{]} \) does not have a \( d^4 \) configuration. Thus, the correct answer is (3) \( \text{(B)} \) and \( \text{(D)} \) only.