twelve easy problems

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