Conformations arise due to rotation around

Options

A. Carbon-Carbon double bond
B. Carbon-Carbon triple bond
C. Carbon-Carbon single bond
D. All of these

Answer

**Step-by-Step Text Solution:**

1. **Understanding Conformations:**
Conformations are different spatial arrangements of atoms in a molecule that can be interconverted by rotation around single bonds. The key point here is that these arrangements arise due to the rotation around single bonds.

2. **Single vs. Double Bonds:**
In organic chemistry, single bonds (sigma bonds) allow for free rotation, while double bonds (pi bonds) restrict rotation. This means that conformations can only arise from single bonds.

3. **Open Chain vs. Closed Chain:**
Conformational isomers can exist in both open-chain and closed-chain (cyclic) structures. In open-chain structures, the rotation around single bonds is unrestricted, allowing for various conformations. In closed-chain structures, the rotation is restricted, leading to fewer conformations.

4. **Newman Projections:**
To visualize conformations, we often use Newman projections. In this representation, one carbon atom is depicted as a dot (the front carbon), and the other as a circle (the back carbon). This helps to illustrate how the groups attached to these carbon atoms can rotate around the bond connecting them.

5. **Infinite Conformations:**
Since the rotation around single bonds in open-chain structures is free, theoretically, there can be an infinite number of conformations for a molecule. Each unique arrangement of atoms resulting from this rotation is considered a different conformer.

**Final Answer:**
Conformations arise due to rotation around single bonds.

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