C-13 NMR Flashcards
1
Q
What is Tetramethylsilane (TMS) used for and why?
A
- Standard for the chemical shift measurements of carbon
- It is chemically unreactive
- It is volatile and can easily be removed from a sample after analysis
2
Q
Disadvantages of MRI Scans
A
• MRI electromagnetic magnet is too strong so scanning areas must be cleared
• Some patients can’t have it:
‣ if they have metal implants
‣ if they have a heart pacemaker
3
Q
NUMBER OF PEAKS
A
Number of different proton environments
4
Q
CHEMICAL SHIFT VALUES
A
Type of proton environment
5
Q
INTEGRATION TRACES (Areas) or RATIO NUMBERS
A
Ratio of protons in each environment
6
Q
SPIN-SPIN SPLITTING PATTERN
A
Number of H in adjacent environment
7
Q
OH and NH compounds
A
- Run normal H1NMR with sample
- Add small amount of D2O (heavy water) to another sample and re-run H1NMR
- OH and NH peak will disappear on spectra as O-D and N-D don’t show up
8
Q
MRI Scans advantages
A
- Harmless as low energy radio waves used
- Non-invasive
- Patient doesn’t feel anything
- Obtained from most body parts
9
Q
Type of radiation used
A
Low energy radio-frequency electromagnetic radiation
10
Q
NUCLEAR MAGNETIC RESONANCE
A
The interaction of materials with the low-energy radio wave electromagnetic radiation.
11
Q
How would you set up a table for H¹ NMR
A
Peak Chemical shift δ/ppm Type of H Relative number of H/H ratio Splitting pattern Adjacent H
