Chapter 14: NMR Flashcards
At what frequency does the NMR at Roger Williams University perform at?
300 Hz (Radio frequency)
Where does an aromatic show up on H-NMR?
7-8 ppm
What information do you get from an H-NMR spectrum?
1)ppm shift-> functional group
2) integration->how many hydrogens are represented by a signal
3) multiplicity-> how many protons are coupled to neighboring carbon.
What does the spinning nucleus produce?
A magnetic field.
Low resolution
No multiplicity, J-J coupling, small magnet
High Resolution
Multiplicity, J-J coupling, large magnet.
What causes shielding?
Enviromental effects were nucleus can’t “see” full magnetic field.
0 ppm would be _____ and 10 ppm would be _____.
0 ppm-up field
10 ppm-down field
What is the multiplicity for C-NMR? What is the integration for C-NMR.
There no multiplicity nor integrations for C-NMR.
What type of magnetic field enviroment is needed for NMR?
There must be a homogenous field.
Shimming
A tool to make the magnetic field homogenous.
What does spinning the NMR sample do?
Averages out the spins to limit the possiblity of inhomogeneties in the magnetic field.
What is the net magnetization?
A vertical arrow pointing up.
Where does net magnetization decay?
In the x-y plane.
What happens when pulse is shut off?
Max magneization.
