TWELVE EASY PROBLEMSTWELVE EASY PROBLEMS
COMBINED PROBLEMS
FORMULA + INFRARED + NMR
SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/ (Mar 2002)
Spectra in these problems were obtained from:
Integrals (relative number of hydrogens)
are given as: 2
The integrals are the simplest ratio.
NOTE ON INTEGRALS:
Expansions are blue and printed above the baseline.
COMBINED PROBLEM #1COMBINED PROBLEM #1
C4H10O
PROBLEM 1 INFRARED SPECTRUMPROBLEM 1 INFRARED SPECTRUM
PROBLEM 1 NMR SPECTRUMPROBLEM 1 NMR SPECTRUM
C4H10O
6
1
1
2
doublet multiplet doublet
Answer to #1
• (CH3)2CHCH2OH
COMBINED PROBLEM #2COMBINED PROBLEM #2
C9H10O2
PROBLEM 2 INFRARED SPECTRUMPROBLEM 2 INFRARED SPECTRUM
1719
PROBLEM 2 NMR SPECTRUMPROBLEM 2 NMR SPECTRUM
C9H10O2
5
23
quartet triplettwo multiplets
Answer to 2
COMBINED PROBLEM #3COMBINED PROBLEM #3
C10H12O
PROBLEM 3 INFRARED SPECTRUMPROBLEM 3 INFRARED SPECTRUM
1688
PROBLEM 3 NMR SPECTRUMPROBLEM 3 NMR SPECTRUM
C10H12O
5 1
6
doubletseptet
Answer #3
COMBINED PROBLEM #4COMBINED PROBLEM #4
C5H10O2
PROBLEM 4 INFRARED SPECTRUMPROBLEM 4 INFRARED SPECTRUM
1712
C5H10O2
PROBLEM 4 NMR SPECTRUMPROBLEM 4 NMR SPECTRUM
1
2
3
4
triplettriplet
two overlappingmultiplets (2 + 2)
Answer
COMBINED PROBLEM #5COMBINED PROBLEM #5
C9H12
PROBLEM 5 INFRARED SPECTRUMPROBLEM 5 INFRARED SPECTRUM
C9H12
PROBLEM 5 NMR SPECTRUMPROBLEM 5 NMR SPECTRUM
5
1
6
septet doublet
Answer to 5
• Isopropyl benzene
COMBINED PROBLEM #6COMBINED PROBLEM #6
C9H12O
PROBLEM 6 INFRARED SPECTRUMPROBLEM 6 INFRARED SPECTRUM
C9H12O
5
1 12
3
PROBLEM 6 NMR SPECTRUMPROBLEM 6 NMR SPECTRUM
triplet quintet triplet
Answer 6
CORRELATION CHARTSCORRELATION CHARTS
acid
BASIC INFRARED KNOWLEDGEBASIC INFRARED KNOWLEDGE
OH 3600NH 3400
CH 3000
C N 2250C C 2150
C=O 1715
C=C 1650
C-O 1100
3300 3100 2900 2850 2750
3000
1800 1735 1725 1715 1710 1690
=C-H -C-H-CHO
C-H
ketoneesteracidchloride
aldehydeamide
anhydride : 1810 and 1760
CH2 and CH3 bend : 1465 and 1365
BASE VALUES
Also remember the effects of H-bonding, conjugation and ring size.
benzene C=C : between 1400 and 1600
EXPANDED CH
EXPANDED C=O
NMR Correlation ChartNMR Correlation Chart
12 11 10 9 8 7 6 5 4 3 2 1 0
-OH -NH
CH2FCH2ClCH2BrCH2ICH2OCH2NO2
CH2ArCH2NR2
CH2SC C-HC=C-CH2
CH2-C-O
C-CH-C
C
C-CH2-CC-CH3
RCOOH RCHO C=C
H
TMS
HCHCl3 ,
(ppm)
DOWNFIELD UPFIELD
DESHIELDED SHIELDED
Ranges can be defined for different general types of protons.This chart is general, the next slide is more definite.
APPROXIMATE CHEMICAL SHIFT RANGES (ppm) FOR SELECTED TYPES OF PROTONS
R-CH3 0.7 - 1.3
R-C=C-C-H 1.6 - 2.6
R-C-C-H 2.1 - 2.4
O
O
RO-C-C-H 2.1 - 2.5O
HO-C-C-H 2.1 - 2.5
N C-C-H 2.1 - 3.0
R-C C-C-H 2.1 - 3.0
C-H 2.3 - 2.7
R-N-C-H 2.2 - 2.9
R-S-C-H 2.0 - 3.0
I-C-H 2.0 - 4.0
Br-C-H 2.7 - 4.1
Cl-C-H 3.1 - 4.1
RO-C-H 3.2 - 3.8
HO-C-H 3.2 - 3.8
R-C-O-C-H 3.5 - 4.8
O
R-C=C-H
H
6.5 - 8.0
R-C-H
O
9.0 - 10.0
R-C-O-H
O
11.0 - 12.0
O2N-C-H 4.1 - 4.3
F-C-H 4.2 - 4.8
R3CH 1.4 - 1.7R-CH2-R 1.2 - 1.4 4.5 - 6.5
R-N-H 0.5 - 4.0 Ar-N-H 3.0 - 5.0 R-S-H
R-O-H 0.5 - 5.0 Ar-O-H 4.0 - 7.0
R-C-N-H
O
5.0 - 9.0
1.0 - 4.0R-C C-H 1.7 - 2.7
Monosubstituted
cis-1,2-
trans-1,2-
1,1-
Trisubstituted
Tetrasubstituted
C CH
R H
H
C CH
R R
H
C CR
H R
H
C CR
R R
R
C CR
R R
H
C CR
R H
H
Disubstituted
10 11 12 13 14 15
1000 900 800 700 cm-1
s s
m
s
s
s
=C-H OUT OF PLANE BENDING
ALKENES
10 11 12 13 14 15
1000 900 800 700 cm-1
Monosubstituted
Disubstituted
ortho
meta
para
Trisubstituted
1,2,4
1,2,3
1,3,5
BENZENES
s s
s
s s
s
s
s
s
m
m
m
mOOPS
RING H’s
combination bands