Question

There are seven constitutional isomers with the formula \(\mathrm{C}_{4} \mathrm{H}_{10} \mathrm{O}\). Draw as many as you can.

Short answer

There are 7 constitutional isomers for \(\mathrm{C}_4\mathrm{H}_{10}\mathrm{O}\) including 4 alcohols and 3 ethers.

Step-by-step solution

Understand the Problem

The problem asks us to draw all possible constitutional isomers for the molecular formula \(\mathrm{C}_4\mathrm{H}_{10}\mathrm{O}\). Constitutional isomers have the same molecular formula but differ in the connectivity of their atoms. For \(\mathrm{C}_4\mathrm{H}_{10}\mathrm{O}\), this means creating different chains and positions for the oxygen atom (as alcohols or ethers).

Draw Primary Alcohols

Start by considering the four-carbon chains and placing the \(\mathrm{OH}\) group at different carbons. Possible structures are:1. Butan-1-ol (1-butanol) - \(\mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}_2\mathrm{CH}_2\mathrm{OH}\)2. Butan-2-ol (2-butanol) - \(\mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}(\mathrm{OH})\mathrm{CH}_3\)3. 2-Methylpropan-1-ol (isobutanol) - \(\mathrm{(CH}_3\mathrm{)_2CHCH}_2\mathrm{OH}\)4. 2-Methylpropan-2-ol (tert-butanol) - \(\mathrm{(CH}_3\mathrm{)_3COH}\)

Explore Ethers

Now consider ethers, where the \(\mathrm{O}\) atom is between two carbon segments:1. Diethyl ether - \(\mathrm{CH}_3\mathrm{CH}_2\mathrm{OCH}_2\mathrm{CH}_3\)2. Methyl propyl ether - \(\mathrm{CH}_3\mathrm{OCH}_2\mathrm{CH}_2\mathrm{CH}_3\)3. Methyl isopropyl ether - \(\mathrm{CH}_3\mathrm{OCH(CH}_3\mathrm{)_2}\)

Verify and Review

Verify that all structures respect the molecular formula \(\mathrm{C}_4\mathrm{H}_{10}\mathrm{O}\). Each drawing should have exactly four carbons, ten hydrogens, and one oxygen. Count the total number of isomers, ensuring that structures are not repeated and no potential structural isomers are missed.

Key concepts

Molecular Formula

A molecular formula is a concise way of representing the number and types of atoms in a molecule. It provides critical information about the composition without detailing how these atoms are connected. For example, the molecular formula \( \mathrm{C}_4\mathrm{H}_{10}\mathrm{O} \) reveals there are four carbon atoms, ten hydrogen atoms, and one oxygen atom in each molecule. This formula doesn't indicate the layout of these atoms, just the fact that they are present in these quantities.

• Carbon atoms: 4
• Hydrogen atoms: 10
• Oxygen atoms: 1

Though straightforward, molecular formulas serve as the starting point for determining the structure and potential function of the compound.

Isomers

Isomers are fascinating because they allow multiple compounds to share the same molecular formula but have different properties and structures. In this scenario, we are discussing constitutional isomers. Constitutional isomers, also known as structural isomers, differ in the connectivity of their atoms.
For \( \mathrm{C}_4\mathrm{H}_{10}\mathrm{O} \), the challenge is to rearrange the atoms in various ways without changing the molecular formula. They can be rearranged to form either alcohols or ethers. While these isomers share the same atomic components, their properties, such as boiling and melting points, can vary significantly.

Alcohols

Alcohols are a class of compounds characterized by the presence of an \( \mathrm{OH} \) (hydroxyl) group. In the case of \( \mathrm{C}_4\mathrm{H}_{10}\mathrm{O} \), four possible alcohols can be drawn by positioning the hydroxyl group in different locations. Each position corresponds to a unique alcohol with its distinct connectivity:

• Butan-1-ol: The \( \mathrm{OH} \) group is at the end of a straight chain.
• Butan-2-ol: The \( \mathrm{OH} \) group is in the middle of a four-carbon chain.
• 2-Methylpropan-1-ol: The \( \mathrm{OH} \) group is on a branched chain.
• 2-Methylpropan-2-ol: The \( \mathrm{OH} \) group is on the central carbon of a branched chain.

Each configuration results in different physical and chemical properties, showcasing how versatile the structure of organic compounds can be.

Ethers

Ethers differ from alcohols because, instead of a hydroxyl group, they include an oxygen atom bonded to two carbon groups. For the molecular formula \( \mathrm{C}_4\mathrm{H}_{10}\mathrm{O} \), three possible ether structures can be drawn:

• Diethyl Ether: Here, an oxygen atom links two ethyl groups.
• Methyl Propyl Ether: This structure involves an oxygen bond between a methyl group and a propyl group.
• Methyl Isopropyl Ether: The oxygen bridges a methyl group and an isopropyl group.

The unique placement of the oxygen within these carbon groups affects the ether's reactivity and volatility. Ethers are often used as solvents in laboratories due to their relatively low reactivity, highlighting their importance in chemical applications.