TMS Flashcards
1
Q
What does TMS have?
A
12 H all in same environment with no polarity
2
Q
What is the chemical shift of TMS?
A
0
3
Q
Draw TMS
A
Si with 4 methyl groups around it
4
Q
Why does TMS give a single strong peak?
A
All protons are shielded exactly the same amount
5
Q
Why is TMS used as a reference point?
A
1) Volatile - evaporates off leaving pure sample
2) Doesn’t interact with sample molecules - doesn’t modify environment so doesn’t affect chemical shift
3) Most organic compounds have chemical shifts that are positive compared to TMS
6
Q
Why are atoms of H magnetic?
A
They have nuclear spin so are able to absorb radio waves. H atoms in different environments absorb different frequency radio waves. Wavelength reveals environment of H
