Tertiary nitro compounds cannot show tautomerism becauses :

Options

A. They are very stable .
B. They isomerise to give secondary intro compounds
C. They do not have labile hydrogen atom.
D. They are highly reactive .

Explanation

To solve the question regarding why tertiary nitro compounds cannot show tautomerism, we can follow these steps:

### Step 1: Understand Tautomerism
Tautomerism is a chemical phenomenon where a compound can exist in two or more interconvertible forms, usually involving the relocation of a hydrogen atom and a shift in the double bond. This process typically requires the presence of acidic hydrogen atoms that can be easily removed.

**Hint:** Tautomerism involves the movement of hydrogen and the rearrangement of bonds.

### Step 2: Identify Tertiary Nitro Compounds
Tertiary nitro compounds are those in which the carbon atom attached to the nitro group (NO2) is a tertiary carbon. This means that the carbon is bonded to three other carbon atoms.

**Hint:** Tertiary carbons are connected to three other carbons, which affects the availability of hydrogen atoms.

### Step 3: Examine the Presence of Labile Hydrogen
Labile hydrogen refers to hydrogen atoms that can be easily removed or transferred. In the case of tertiary nitro compounds, the carbon atom bonded to the nitro group does not have any labile hydrogen atoms. This is because all the hydrogen atoms are bonded to other carbon atoms, making them non-removable.

**Hint:** Labile hydrogen is crucial for tautomerism; without it, tautomerism cannot occur.

### Step 4: Compare with Secondary and Primary Nitro Compounds
In contrast, secondary and primary nitro compounds have at least one labile hydrogen atom (alpha hydrogen) that can participate in tautomerism. For example, secondary nitro compounds have one hydrogen that can be transferred, while primary nitro compounds have two.

**Hint:** Secondary and primary nitro compounds can show tautomerism due to the presence of removable hydrogen atoms.

### Step 5: Conclusion
Since tertiary nitro compounds lack labile hydrogen atoms, they cannot undergo tautomerism. Therefore, the answer to the question is that tertiary nitro compounds cannot show tautomerism because they do not have any labile hydrogen atoms.

**Final Answer:** Tertiary nitro compounds cannot show tautomerism because they do not have labile hydrogen atoms.