4. A structure of molecular formula C5H₁2O has the following NMR: ¹H NMR (300 MHz, CDC13, 21C) 80.92 ppm (t, 3H, J = 7 Hz), 1.20 (s, 6H), 1.50 (q, 2H, J = 7Hz), 1.64 (broad singlet, 1H). What is the chemical shift of each of the three lines in the triplet signal at 0.92 ppm? Propose a reasonable structure given the ¹H NMR data.

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### Nuclear Magnetic Resonance (NMR) Analysis for C₅H₁₂O

**Problem Statement:**

"A structure of molecular formula C₅H₁₂O has the following NMR data:"

**1H NMR (300 MHz, CDCl₃, 21°C):**

- **0.92 ppm** (triplet, 3H, J = 7 Hz)
- **1.20 ppm** (singlet, 6H)
- **1.50 ppm** (quartet, 2H, J = 7 Hz)
- **1.64 ppm** (broad singlet, 1H)

**Questions:**

**1. What is the chemical shift of each of the three lines in the triplet signal at 0.92 ppm?**

**2. Propose a reasonable structure given the ¹H NMR data.**

### Explanation:

**Chemical Shifts Analysis:**

1. **Triplet Signal at 0.92 ppm:**
   - Given the triplet pattern, the signal at 0.92 ppm indicates 3 hydrogens experiencing coupling with neighboring hydrogens (with a coupling constant J = 7 Hz).
   - The chemical shifts for each of the three lines in this triplet signal at 0.92 ppm typically would be spaced symmetrically around the central peak, with a separation of 7 Hz (the coupling constant).

2. **Singlet Signal at 1.20 ppm:**
   - This singlet implicates 6 hydrogens without any neighboring hydrogens to cause coupling.

3. **Quartet Signal at 1.50 ppm:**
   - The quartet pattern indicates 2 hydrogens coupled with three neighboring hydrogens, with a J value of 7 Hz.

4. **Broad Singlet at 1.64 ppm:**
   - This broad singlet suggests 1 hydrogen, likely involved in some form of exchangeable proton environments such as OH (hydroxyl group).

### Proposed Structure:

Based on the NMR data provided, the structure must fit the following criteria:

- Total chemical formula: C₅H₁₂O
- Three hydrogens (triplet at 0.92 ppm), indicating -CH₃ group adjacent to a -CH₂-.
- Six hydrogens (singlet at 1.20 ppm), suggesting presence
Transcribed Image Text:### Nuclear Magnetic Resonance (NMR) Analysis for C₅H₁₂O **Problem Statement:** "A structure of molecular formula C₅H₁₂O has the following NMR data:" **1H NMR (300 MHz, CDCl₃, 21°C):** - **0.92 ppm** (triplet, 3H, J = 7 Hz) - **1.20 ppm** (singlet, 6H) - **1.50 ppm** (quartet, 2H, J = 7 Hz) - **1.64 ppm** (broad singlet, 1H) **Questions:** **1. What is the chemical shift of each of the three lines in the triplet signal at 0.92 ppm?** **2. Propose a reasonable structure given the ¹H NMR data.** ### Explanation: **Chemical Shifts Analysis:** 1. **Triplet Signal at 0.92 ppm:** - Given the triplet pattern, the signal at 0.92 ppm indicates 3 hydrogens experiencing coupling with neighboring hydrogens (with a coupling constant J = 7 Hz). - The chemical shifts for each of the three lines in this triplet signal at 0.92 ppm typically would be spaced symmetrically around the central peak, with a separation of 7 Hz (the coupling constant). 2. **Singlet Signal at 1.20 ppm:** - This singlet implicates 6 hydrogens without any neighboring hydrogens to cause coupling. 3. **Quartet Signal at 1.50 ppm:** - The quartet pattern indicates 2 hydrogens coupled with three neighboring hydrogens, with a J value of 7 Hz. 4. **Broad Singlet at 1.64 ppm:** - This broad singlet suggests 1 hydrogen, likely involved in some form of exchangeable proton environments such as OH (hydroxyl group). ### Proposed Structure: Based on the NMR data provided, the structure must fit the following criteria: - Total chemical formula: C₅H₁₂O - Three hydrogens (triplet at 0.92 ppm), indicating -CH₃ group adjacent to a -CH₂-. - Six hydrogens (singlet at 1.20 ppm), suggesting presence
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