Question

Which of the following coordinate complexes is heteroleptic?

• A. Pentacarbonyliron(0)
• B. Triamminetrinitrocobalt(III)
• C. Tetraamminecopper(II) ion
• D. Tetracyanonickelate(II) ion

Hint:

A heteroleptic complex has more than one kind of ligand.

Answer 1

The Correct Option is B

Step 1: Approach
Read each name and count the kinds of ligand named before the metal.

Step 2: Reading the names
- Pentacarbonyl: one kind (CO).
- Triammine and trinitro: two kinds ($\text{NH}_3$ and $\text{NO}_2^-$).
- Tetraammine: one kind.
- Tetracyano: one kind.

Step 3: Conclusion
Only the cobalt complex has two different ligands, so only it is heteroleptic, option (B).

Final Answer:
Triamminetrinitrocobalt(III) has two types of ligand, so it is heteroleptic, option (B). \[ \boxed{\text{Triamminetrinitrocobalt(III)}} \]