NMR

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  • Created by: Amira200
  • Created on: 04-06-16 10:49
What does NMR spec involve
Interaction of materials with low energy radio frequency radiation
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What is TMS
The standard for chemical shift measurement
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What are the two main requirements for NMR spec
A strong magnetic field applied using an electromagnet. Low energy radio frequency radiation
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What are the two main types of NMR used in organic chemistry
H-1 and 13C
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What is the property of protons and neutrons
They have a spin. Opposite spins pair up
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What generates a magnetic field
Nuclei of some isotopes have an uneven number of nucleons. Therefore the isotopes have an unpaired nucleon which produces a small residual nuclear spin
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What is S the chemical shift
The place at which a nucleus absorbs energy.
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Describe further the use of TMS
The chemical shift is measured relative to TMS.TMS is a reference signal from a standard compound called TMS. Each molecule of TMS has 12 equivalent protons. Chemical shift of TMS is defined as S=0ppm
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Why is a small amount of TMS added when NME spectra are recorded
So that the spectrometer can be calibrated against the TMS reference peak. I is chemically unreactive and volatile so can easily be removed from a sample after running an NMR spec
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Why is a solvent required in NMR spec, what is the solvent used and why is this solvent used
A solvent is required because NMR is usually carried out in solution. Deuterated solvents are used Deuterium. Because it has an isotope of hydrogen with an even number of nucleons. it produces no signal. CDCl3 is removed at the end by evaporation
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What does the number of peaks in a carbon 13 tell you
The number of carbon environments
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What is the use of D2O
Compounds containing OH and NH groups are difficult to identify as the peaks can appear over a wide range of chemical shift patterns with usually no splitting patterns. D2O allows identification of OH and NH groups by exchanging (H) protons with D
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What are the uses of NMR is medicine
MRI scans
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Other cards in this set

Card 2

Front

What is TMS

Back

The standard for chemical shift measurement

Card 3

Front

What are the two main requirements for NMR spec

Back

Preview of the front of card 3

Card 4

Front

What are the two main types of NMR used in organic chemistry

Back

Preview of the front of card 4

Card 5

Front

What is the property of protons and neutrons

Back

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