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11 Cards in this Set
- Front
- Back
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What does NMR stand for? |
Nuclear magnetic resonance spectroscopy |
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What is NMR? |
NMR spectroscopy involves the interaction of materials with the low-energy radio wave region of the electromagnetic spectrum |
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What is NMR used for? |
To determine the structure of a compound |
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What is a real life application of NMR technology? |
MRI (magnetic resonance imaging) to obtain images of soft body tissue. It's non-evasive and the low-energy radio waves don't damage body tissues. |
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What are the 2 types of NMR we study? |
Proton NMR and C-13 NMR |
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What information does C-13 NMR give us? |
The number of peaks tells us the number of carbon environments and the position of the peak (chemical shift) identifies which type of carbon environment it is |
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What symbol is used to represent chemical shift and what units is it measured in? |
δ ppm
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What is chemical shift measured against? |
Tetramethylsilane (TMS) |
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What is the formula of tetramethylsilane? |
(CH3)4Si |
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What is significant about the structure of tetramethylsilane? |
It has 4 C atoms in the same environment 12 H atoms in the same environment. This produces a single peak with δ= 0 ppm. |
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How is TMS used? |
A small sample of TMS is added to the sample to obtain a reference peak at δ = 0 ppm to calibrate it. All other peaks are measured relative to TMS |
