Question

\([ \text{Mn}_2(\text{CO})_{10} ]\) and \([ \text{Co}_2(\text{CO})_8 ]\) structures have:A. Metal-Metal linkage
B. Terminal CO groups
C. Bridging CO groups
D. Metal in zero oxidation stateChoose the correct answer from the options given below:

• A. Only A, B, C
• B. Only B, C, D
• C. Only A, C, D
• D. Only A, B, D

Answer 1

The Correct Option is D

To solve the question, it's essential to understand the structural details of the given compounds, \([ \text{Mn}_2(\text{CO})_{10} ]\) (Manganese carbonyl) and \([ \text{Co}_2(\text{CO})_8 ]\) (Cobalt carbonyl).

1. Metal-Metal Linkage:
   • \([ \text{Mn}_2(\text{CO})_{10} ]\) has a direct Mn-Mn metal-metal bond.
   • Similarly, \([ \text{Co}_2(\text{CO})_8 ]\) features a Co-Co metal-metal bond.
   Therefore, both compounds have metal-metal linkages.
2. Terminal CO Groups:
   • In both \([ \text{Mn}_2(\text{CO})_{10} ]\) and \([ \text{Co}_2(\text{CO})_8 ]\), all carbonyl (CO) groups are terminal. This means they are directly bonded to the metal and not participating as a bridge between two metal centers.
   Thus, both have terminal CO groups.
3. Bridging CO Groups:
   • Neither \([ \text{Mn}_2(\text{CO})_{10} ]\) nor \([ \text{Co}_2(\text{CO})_8 ]\) contains bridging CO groups. In bridging, the CO acts as a bridge between two metal atoms, which is not the case here.
   Thus, this statement is incorrect for both compounds.
4. Metal in Zero Oxidation State:
   • Typically, in metal carbonyls like \([ \text{Mn}_2(\text{CO})_{10} ]\) and \([ \text{Co}_2(\text{CO})_8 ]\), the metal exists in a zero oxidation state. This is because the carbonyl ligands are strong field ligands and create a neutral complex overall.
   Hence, both compounds have metals in the zero oxidation state.

Considering the above explanations, the elements satisfied are Metal-Metal linkage (A), Terminal CO groups (B), and Metal in zero oxidation state (D). Therefore, the correct answer is:

Only A, B, D