Types of isomerism shown by `[Cr(NH_3)_5NO_2]Cl_2` is

Options

A. Co - ordination
B. Geometrical
C. Optical
D. Linkage

Answer

To determine the types of isomerism shown by the complex compound \([Cr(NH_3)_5NO_2]Cl_2\), we will analyze each type of isomerism step by step.

### Step 1: Identify the Complex
The complex given is \([Cr(NH_3)_5NO_2]Cl_2\). Here, chromium (Cr) is the central metal ion, and it is coordinated to five ammonia (NH3) ligands and one nitro (NO2) ligand, with two chloride (Cl) ions outside the coordination sphere.

**Hint:** Identify the central metal and the ligands attached to it.

### Step 2: Check for Coordination Isomerism
Coordination isomerism occurs when there are different arrangements of cationic and anionic parts in a complex. In this case, there are no separate cationic and anionic entities since the complex is neutral with the chloride ions outside. Therefore, coordination isomerism does not apply here.

**Hint:** Look for the presence of cationic and anionic parts in the complex.

### Step 3: Check for Geometrical Isomerism
Geometrical isomerism arises when ligands can occupy different positions around the central metal ion. In octahedral complexes, this can lead to cis and trans forms. Since there are five NH3 ligands and one NO2 ligand, the NO2 can be positioned either adjacent to (cis) or opposite to (trans) the NH3 ligands. Thus, geometrical isomerism is possible.

**Hint:** Consider the arrangement of ligands around the central metal ion and whether they can be adjacent or opposite.

### Step 4: Check for Optical Isomerism
Optical isomerism occurs when a compound can exist in two non-superimposable mirror images (enantiomers). For a complex to exhibit optical isomerism, it must lack a plane of symmetry. In this case, since the arrangement of ligands can lead to a chiral configuration, optical isomerism is also possible.

**Hint:** Determine if the arrangement of ligands can create non-superimposable mirror images.

### Step 5: Check for Linkage Isomerism
Linkage isomerism occurs when a ligand can attach to the metal in more than one way. The nitro ligand (NO2) can coordinate through the nitrogen (N) or the oxygen (O) atom, leading to different isomers. Therefore, linkage isomerism is also possible in this complex.

**Hint:** Identify if any ligands can bind to the metal in multiple ways.

### Conclusion
The complex \([Cr(NH_3)_5NO_2]Cl_2\) can exhibit the following types of isomerism:
1. Geometrical isomerism (due to different arrangements of ligands).
2. Optical isomerism (due to the possibility of chiral arrangements).
3. Linkage isomerism (due to the ambident nature of the nitro ligand).

**Final Answer:** The types of isomerism shown by \([Cr(NH_3)_5NO_2]Cl_2\) are geometrical, optical, and linkage isomerism.