1. IR
Infrared Spectroscopy
Identify the functional group(s)

2. Electromagnetic Spectrum

3. Bond Vibrations
Energy
absorption
radiation
Amplitude

4. Stretching
Bending

5. Classical IR Spectrometer

7. NaCl IR Plates
A drop of sample is place between the NaCl plates

8. NaCl cell for solutions

10. Wavenumber cm-1
E = h= hc/

11. Characteristic IR Absorption Frequencies
cm-1
Bond
C-H Alkanes
C-H Alkenes
C-H Arenes
C-O Alcohols, ethers
C=O Aldehydes, ketones
O-H Alcohols
Acids
N-H Amines

12. Alcohol
-OH
C-H
-O-R

13. PrimaryAmine
-NH2

14. Secondary Amine
N-H

15. Ketone
C=O

16. Aldehyde
RCO-H
C=O

17. Carboxylic Acid OH
C=O

18. Ester
C-O
C=O

19. Functional Group?
Carbonyl group -- Ketone

20. Functional Group?
Alcohol

21. Functional Group?
Carboxylic Acid

22. Functional Group?
Ester

23. Functional Group?
amine (secondary)

24. C8H8O
C6H5COCH3

25. C3H8O
isopropyl alcohol

26. C4H8O2
CH3COOCH2CH3

27. C5H10O
CH3COCH2CH2CH3