IR spec Flashcards
(31 cards)
1
Q
Wavenumber=
A
No. of whole waves in 1 cm
2
Q
X-H single bond
A
2500-3500
3
Q
Triple bonds
A
2000-2500
4
Q
Double bonds
A
1500-2000
5
Q
X-Y single
A
Fingerprint region- <1500
6
Q
Non-dipole moment bonds
A
Use Ramen spectroscopy- IR doesn’t work
7
Q
Tetrahedral C-H
A
Just under 3000
8
Q
Trigonal C-H
A
Just over 3000
9
Q
-C 3- C-H
A
Strong, sharp at 3300
10
Q
N-H
A
Sharp at 3300
11
Q
NH2
A
Doublet- symmetric(3300) & antisymmetric(3400)
12
Q
O-H
A
v.broad with H bonding
13
Q
COOH
A
Broad, v-shaped
14
Q
C3-N
A
Strong, 2250
15
Q
C3-C
A
Weaker 2100-2250
16
Q
C2-C
A
Weak, 1635-1690
17
Q
Benzene
A
A number of weak-medium peaks, 1625-1450
18
Q
NO2
A
Symmetric(1530)& asymmetric(1350)
19
Q
Carbonyl general rule
A
Strong peak
Strengthens bond=higher frequency
Weakens bond=lower frequency
20
Q
Ketone
A
1715
21
Q
Acid chloride
A
1750-1820
22
Q
Amide
A
1640-1690
23
Q
Carboxylic acid
A
1730
24
Q
Ester
A
1745
25
Aldehyde
1730
26
Acid anhydride
Symmetric (1820) & antisymmetric (1750)
27
Conjugated ketone
1690
28
6 to 5 membered ring
+30
29
5 to 4 membered ring
+35
30
4 to 3 membered ring
+35
31
Ring reasoning
Smaller rings, C can't move as much due to more resistance, so C-C bonds must be compressed
Requires energy so higher frequency
