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1. |
Two common methods for measuring T1 are: (i) Using a saturation-recovery experiment (ii) Using an inversion-recovery experiment Explain in detail how each of these experiments is performed. Contrast the experiments in terms of their accuracy, and explain how you would measure T1 values for several species in the same solution. Answer |
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2. |
The 1H NMR spectrum of 1,4-dioxan in water shows two resonances (dioxan resonance at d 3.4 ppm and the H2O resonance at d 4.5 ppm). |
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i) |
Explain how the relaxation times (T1 values) of the protons in 1,4-dioxan (B) and water could be measured using the pulse sequence below. |
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ii) |
How could this pulse sequence be used to eliminate or suppress the signal from water while observing the signal from dioxan? |
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Answer |
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3. |
The basic 13C spectrum and 3 DEPT spectra were recorded on a sample of the compound acronycine (C20H19NO3) in CDCl3 solution. From the spectra, what can you deduce about the structure of acronycine? Answer |
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