Q73P - Chemistry: Molecular Nature Of Matter And Change

Question

For any of the following that can exist as isomers, state the type of isomerism and draw the structures:

1. [Pt(CH₃NH₂)₂Br₂] 
2. [Pt(NH₃)₂FCl]  
3. [Pt(H₂O)(NH₃)FCl]

Step-by-Step Solution

Answer

The chemical structures given into the questions show isomerism. They exist as geometric (cis-trans) isomerism. 

Step 1: Concept Used – Isomerism

Definition of different kinds of isomers

 

1. Constitutional (structural) isomers - same formula, differently connected atoms; they can occur in two types:

 

1. Coordination isomers - they occur when the structure of the whole compound is the same, but the structure of complex ion is different

 

1. Linkage isomers - they occur when the structure of the complex ion is the same, but the donor atom which ligand uses is different

 

1. Stereoisomers - they have the same connections between atoms, but the atoms have different spatial arrangements; they occur in two types:

 

1. geometric (cis-trans) isomers - different spatial arrangements of atoms or groups, relative to the central metal ion.

 

2.2   Optical isomers - they occur when molecule cannot be superimposed with               its mirror image. 

 

Step 2: Elucidation of type of isomerism and structure

$\left[\text{Pt}{\left({\text{CH}}_3{\text{NH}}_2\right)}_2{\text{Br}}_2\right]$- geometric (cis-trans) isomers

 

Step 3: Elucidation of type of isomerism and structure

[Pt(NH₃)₂FCl] - geometric (cis-trans) isomers

Step 4: Elucidation of type of isomerism and structure

$\left[\text{Pt}\left({\text{H}}_2\text{O}\right)\left({\text{NH}}_3\right)\text{FCl}\right]$- geometric (cis-trans) isomers