Infrared spectroscopy Mass spectroscopy
= identifies molecules by how they VIBRATE =identifies molecules by looking at their FRAGMENT IONS
Different bonds vibrate at different frequencies due to: Molecular ion = peak furthest to the right, same Mr as actual
- Bond strength molecule
- Bond length - M + e- → M+ + 2e-
- Mass of bonded atoms Fragment ions = M+ hit by another e- & split further
- Environment atoms are in - Peak at Mr of fragment ion
Doesn’t work on diatomic atoms - polarities can’t switch M+1 peak = if 13C used instead of 12C, Mr will be 1 bigger ∴M+1
“The peak at ____ represents the bond ___. Therefore it peak
contains a ___ functional group.” M+2 peak = if 37Cl used instead of 35Cl, Mr will be 2 bigger ∴M+2
Fingerprint region = below 1500 peak
Can be used to check if a molecule in impure.
pentane:
pentanol:
[CH3CH2CH2]+
[CH3CH2] [CH3CH2CH
+ 2CH2]+
[CH3CH2CH
2CH2CH3]+
= identifies molecules by how they VIBRATE =identifies molecules by looking at their FRAGMENT IONS
Different bonds vibrate at different frequencies due to: Molecular ion = peak furthest to the right, same Mr as actual
- Bond strength molecule
- Bond length - M + e- → M+ + 2e-
- Mass of bonded atoms Fragment ions = M+ hit by another e- & split further
- Environment atoms are in - Peak at Mr of fragment ion
Doesn’t work on diatomic atoms - polarities can’t switch M+1 peak = if 13C used instead of 12C, Mr will be 1 bigger ∴M+1
“The peak at ____ represents the bond ___. Therefore it peak
contains a ___ functional group.” M+2 peak = if 37Cl used instead of 35Cl, Mr will be 2 bigger ∴M+2
Fingerprint region = below 1500 peak
Can be used to check if a molecule in impure.
pentane:
pentanol:
[CH3CH2CH2]+
[CH3CH2] [CH3CH2CH
+ 2CH2]+
[CH3CH2CH
2CH2CH3]+
