C onsider the reaction `C_(3)H_(7)OH+CH_(2)-N_(2)` (Diazomethane) `overset(HBF_(4))rarr`
The leaving group is:

Options

A. `CH_(2)^(-)`
B. `N_(2)`
C. `BF_(4)^(-)`
D. `C_(3)H_(7)O^(-)`

Explanation

To solve the question regarding the reaction between propanol (C₃H₇OH) and diazomethane (CH₂N₂) in the presence of HBF₄, we need to identify the leaving group in this reaction. Here’s the step-by-step solution:

### Step 1: Understand the Reactants
We have two main reactants: propanol (C₃H₇OH) and diazomethane (CH₂N₂). Diazomethane can exist in different forms, but we will focus on its reactivity in this context.

### Step 2: Analyze Diazomethane Structure
Diazomethane can be represented as CH₂=N₂ or as CH₂-N=N. The key feature here is that one of the nitrogen atoms can act as a leaving group during the reaction.

### Step 3: Reaction Mechanism
When diazomethane reacts with HBF₄, it generates a proton (H⁺) that can facilitate the reaction. The H⁺ ion interacts with the diazomethane, leading to the formation of a carbocation.

### Step 4: Formation of Carbocation
The protonation of diazomethane leads to the formation of a carbocation (CH₃⁺) and nitrogen gas (N₂) as a byproduct. The nitrogen gas is a stable molecule and will leave the reaction mixture.

### Step 5: Identify the Leaving Group
In this reaction, the nitrogen gas (N₂) is the leaving group. It is released from the reaction, making it the species that departs during the transformation.

### Step 6: Conclusion
Thus, the leaving group in the reaction between propanol and diazomethane in the presence of HBF₄ is nitrogen (N₂).

### Final Answer
The leaving group is nitrogen (N₂).

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