Question

Which from following complexes is an example of \(\text{MA}_4\text{BC}\) type distereoisomers ?

• A. \([\text{Pt}(\text{NH}_3)(\text{H}_2\text{O})\,\text{Cl}_2]\)
• B. \([\text{Pt}(\text{NH}_3)_4\,\text{ClBr}]^{2+}\)
• C. \(\text{Pt}(\text{NH}_3)_2\,\text{Cl}_2\)
• D. \([\text{Co}(\text{NH}_3)_4\,\text{Cl}_2]^+\)

Hint:

MA4BC means four identical ligands and two different ligands B and C in an octahedral complex.

Answer 1

The Correct Option is B

Step 1: Count ligand types
Write each complex as M with letters. (A) 1 + 1 + 2 = four ligands. (C) 2 + 2. (D) 4 + 2. (B) 4 + 1 + 1.

Step 2: Match
The pattern 4 + 1 + 1 is MA4BC, which is option (B).

Step 3: Isomerism
With six positions, B and C can be placed at 90 degrees (cis) or 180 degrees (trans), so two geometrical isomers (diastereomers) exist.

Step 4: Answer
Option (B).

Final Answer:
Option (B) has the ligand pattern 4 + 1 + 1. This is option (B). \[ \boxed{\text{(B) }[\text{Pt}(\text{NH}_3)_4\text{ClBr}]^{2+}} \]