IR interpretation

1. O
R2
R1

2. Ethers
• Ethers are the derivatives of alcohols & Show
characteristic C-O-C bands .
•Masses of C-C and C-O are comparable, their
force constant are quite close.
•But due to large difference in their dipole-
moments, the C-O bonds are stronger as
compared to C-C bonds
•Ethers show only one characteristic band in the
region 1300-1050 cm-1 .

3. • The identification of ether in an unknown
compound is difficult in presence of another
oxygenated compound because many other strong
bands appear in the same region .
• Saturated aliphatic ethers show a strong band in
the region 1150-1070 cm-1 for asymmetric C-O-C
stretching and another at 940 cm-1 for symmetricall
•Stretching.
•The C-O-C absorption spectrum of higher members
lie in the broader region 1250-1070 cm-1

4. Di –n-butyl ether
C-H (str)in methyl -2960 cm-1 .
C-O (str)-2880 cm-1 .
C-H def (CH2)-1462 cm-1 .
C-H def (CH3)-1372 cm-1 .
C-O (str)in C-O-C -1124

5. Di-n-propyl ether
C-H (Str) C-O (Str)
C-H (Def)
C-H (Str)in CH3- 2980 cm-1 C-O (Str)-1060 cm-1
C-H(Str) in CH2- 2920 cm-1
C-H(Def)in CH3- 1430 cm-1
C-H(Def)in CH2- 1450cm-1

6. Phenetole
C-H(Str)Aro.
C-O(str)
C=C (Str)
C-H (Str)-3000 cm-1
C=C(Str)-1460 cm-1
C-O (Str)-1100 cm-1
C-H (Def)-700 cm-1