Problem 133 - A Complete Resource Book in Chemistry for JEE Main

Question

The number of \(\mathrm{N}-\mathrm{CH}_{2}-\mathrm{N}\) bonds in urotropine is

Step-by-Step Solution

Answer

Urotropine has 6 \(\mathrm{N{-}CH_2{-}N}\) bonds.

Step 1: Understand the structure of urotropine

Urotropine, also known as hexamethylenetetramine, is a chemical compound with the formula \((\mathrm{CH}_2)_6\mathrm{N}_4\). It is a heterocyclic organic compound and forms a cage-like structure consisting of a network of carbon and nitrogen atoms.

Step 2: Analyze the molecular structure

Urotropine has a symmetrical, cage-like structure with a total of four nitrogen atoms and six methylene groups (\(\mathrm{CH}_2\)). Each nitrogen atom is connected to three methylene groups through \(\mathrm{N{-}CH_2{-}N}\) bonds, forming a network of interlinked quaternary nitrogens.

Step 3: Count the \(\mathrm{N{-}CH_2{-}N}\) connections

Each methylene group (\(\mathrm{CH}_2\)) in urotropine acts as a bridge between two nitrogen atoms, forming a bond sequence \(\mathrm{N{-}CH_2{-}N}\). As there are six \(\mathrm{CH}_2\) groups in the compound, there are exactly six \(\mathrm{N{-}CH_2{-}N}\) bonds.

Step 4: Confirm the structure

Ensure that the structural analysis aligns with urotropine's chemical representation, confirming that each of the six methylene groups is correctly counted as part of an \(\mathrm{N{-}CH_2{-}N}\) bond spanning the cage structure.

Key Concepts

Hexamethylenetetramine

Urotropine, more formally known as hexamethylenetetramine, is a fascinating chemical compound with a unique design. Its chemical formula is \((\mathrm{CH}_2)_6\mathrm{N}_4\), a conglomeration of carbon and nitrogen atoms arranged distinctively to form a symmetrical cage. This heterocyclic compound is utilized in various industrial applications, including as a chemical intermediate and even in some medicinal preparations. Its cage-like arrangement is what grants it stability and the ability to act as a stable storage medium for gases in the industry. Understanding hexamethylenetetramine offers insight into the complexity and beauty of molecular structures.

Molecular Structure Analysis

Analyzing the structure of complex molecules like urotropine can feel like piecing together a 3D puzzle. Urotropine's molecular structure is a cage comprising four nitrogen atoms nearly equally spaced and interlinked by six methylene \((\mathrm{CH}_2)\) groups.
This creates a symmetrical arrangement in which every nitrogen atom connects to three methylene groups, establishing a mesh of interconnected nitrogens.

• The repetitive unit in the structure is a nitrogen atom bonded to three methylene groups, which plays a vital role in lending the compound its cage-like configuration.
• The symmetry and repetition of these units contribute to its structural stability and uniformity.

The visualization of these bonds is crucial for appreciating how the molecule maintains its intricate and stable form.

Heterocyclic Compounds

Heterocyclic compounds are a category of cyclic compounds that include atoms of at least two different elements within the ring structure. In the case of urotropine, the ring is formed with nitrogen and carbon atoms, qualifying it as a heterocyclic compound. This category of compounds is widespread in chemistry and biology due to its diverse applications.

Heterocyclic compounds like urotropine are important for several reasons:

• They often possess unique chemical reactivity due to the presence of different atoms in their rings, making them valuable in synthetic chemistry.
• Their structures can offer a robustness that bypasses the limitations of purely carbon ring systems, thereby increasing their functional utility in pharmaceuticals and materials science.

These compounds are crucial for the development of various chemical processes and products.

Chemical Bonding

Chemical bonding is fundamental to understanding how molecules like urotropine are held together. In urotropine, the nitrogen and carbon atoms bond covalently.
This means they share electrons to fulfill every atom's desire for electrons, facilitating a stable arrangement.
Each methylene \((\mathrm{CH}_2)\) group forms bonds with two nitrogen atoms, establishing the \(\mathrm{N{-}CH_2{-}N}\) linkages seen in this compound.

• Covalent bonds in urotropine contribute significantly to its stability, as the symmetrical cage-like structure evenly distributes the molecular forces throughout the compound.
• The symmetry in bonding ensures that each bond is equally balanced, allowing the compound to maintain its robust 3D shape.

Understanding these bonds provides more than just a picture of its connectivity; it also unveils the molecule’s stability and functionality.