organic practical data

JS Organic Practical Course

Carbon-13 and Carbon-DEPT Spectra

Additional 2D and other NMR data

General IR information

Selected reading list

Generic Carbon-13 data is provided for various products

produced in the Junior Sophister Organic Chemistry Practical Course

A standard carbon-13 spectrum (proton decoupled) is provided.

Routine Carbon-13 nmr spectra are not run because of time constraints.

Remember that the carbon-13 nuclide only constitutes 1% of all carbon isotopes.

All the samples were prepared in CDCl3. The CDCl3 solvent signal is observed as a triplet centred at 77.0 ppm..

The relevant peaks are listed in ppm. The excitation frequency for the 9.4T magnet is 100.62MHz

Additional carbon spectra to determine the number of protons attached to a given signal are provided using

the Carbon-13 DEPT 135° and Carbon-13 DEPT 90° experiments. These spectra are displayed in a comparative format.

Carbon DEPT experiments are read as follows:

DEPT 135° CH2 resonances are inverted

CH3 and CH remain normal upward phase

DEPT 90° CH resonances only are observed

C with no protons attached are NOT seen in DEPT experiments

Carbon-13 spectra are provided for the following products :

Experiment 1 Cis-5,5,10,10-Tetrachlorotricyclo[7.1.0.04,6]decane

2A Diethyl Benzylphosphonate

2B (E,E)-1,4-Diphenyl-1,3-butadiene

3A cis-Cyclohex-4-ene-1,2-dicarboxylic acid anhydride

3B cis-Cyclohex-4-ane-1,2-dicarboxylic acid anhydride

4 2,6-Dimethyl-5-hydroxy-heptan-3-one

5A 1-Phenyl-1,4-butanediol

5B γ-Phenyl-γ-butyrolactone

6 (-)cis-Caran-trans-4-ol

A phosphorous-31 spectrum is provided for DethylBenzylphosphonate (2A)

Phosphorous-31 is an NMR active spin ½ nuclide The excitation frequency for the 9.4T magnet is 162 MHz


On closer inspection of the carbon-13 spectrum - three additional signals are observed

What can these signals be attributed to ?

Experiment 2a 13C NMR Diethyl Benzylphosphonate

Experiment 2a 13C NMR Diethyl Benzylphosphonate

Why are the carbon-13 split into doublets ?

Experiment 2a 31P NMR Diethyl Benzylphosphonate

Experiment 2b 13C NMR (E,E)-1,4-Diphenyl-1,3-butadiene

Experiment 3a cis-Cyclohex-4-ene-1,2-dicarboxylic acid anhydride

Experiment 3b cis-Cyclohex-4-ane-1,2-dicarboxylic acid anhydride

Experiment 4 2,6-Dimethyl-5-hydroxy-heptan-3-one

Experiment 5a 1-Phenyl-1,4-butanediol

Experiment 5b -Phenyl- -butyrolactone

Experiment 6 (-)cis-Caran-trans-4-ol

Additional NMR spectral data to aid

structural determination

The information in the spectral data is provided to :

simplify some complexity found in proton spectra

link proton and carbon data

allow clearer explanation(s) of the structure

Types of data are supplied :

-2D homonuclear correlation spectra (HH COSY or TOCSY)

-2D heteronuclear correlation spectra (CH COSY or HSQC)

-2D Long range heteronuclear correlation spectra (HMBC )

-1D Selective TOCSY (homonuclear correlation)

-1D Selective Nuclear Overhauser spectra (NOE)

Additional NMR Data is supplied for experiments :

-1 cis-5,5,10,10-Tetrachlorotricyclo[7.1.0.04,6]decane

-2b ( (E.E)-1,4-diphenyl-1,3-butadiene)

-3a cis-Cyclohex-4-ene-1,2-dicarboxylic Acid Anhydride

-3b cis-Cyclohexane-1,2-dicarboxylic Acid Anhydride

-4 (2,6-Dimethyl-3-heptan-5-one)

-5a (1-Phenylbutane-1,4-diol)

-5b ( -Phenyl- -butyrolactone)

-6 (cis-Caran-trans-4-ol)

Summary of other NMR experiments

Connections through bonds and space

• Correlation Spectra (COSY) – through bond connections

HH COSY - connections of proton spins through bonds

1D selective TOCSY (HH COSY like)

CH COSY (HSQC) - direct link of carbon to proton(s)

Long range CH COSY (HMBC)

• Connections through space

Nuclear Overhauser (NOE) experiments

1D : 1D selective NOE

2D : NOESY, ROESY

How to read a COSY

• HH COSY

diagonal is the 1D spectrum

off diagonal signal(s) display the connections of the spins

true signal must have mirror image across the diagonal

• CH COSY

signals are the direct correlation between the C and H

• Long range CH COSY

often can correlate several protons to a carbon

(or vice versa - whichever is most appropriate )

e.g. links carbon signals with NO protons directly attached

1 Cis-5,5,10,10-Tetrachlorotricyclo[7.1.0.04,6]decane

CH COSY (edited HSQC)

Direct correlation of the hydrogen to carbon resonances

what is the second compound ?

1H

13C

2B CH COSY (E,E)-1,4-Diphenyl-1,3-butadiene 13C - HSQC NMR experiment

(ppm) 7.40 7.20 7.00 6.80 6.60

(ppm)

134.0

132.0

130.0

128.0

126.0

1

2

3

4

1'2'

3'

4' 6'5'

Direct correlation of the

hydrogen to carbon resonances

2B HH COSY (E,E)-1,4-Diphenyl-1,3-butadiene

(ppm) 7.60 7.40 7.20 7.00 6.80 6.60

(ppm)

7.60

7.40

7.20

7.00

6.80

6.60

6.40

(ppm) 7.60 7.40 7.20 7.00 6.80 6.60

(ppm)

7.60

7.40

7.20

7.00

6.80

6.60

6.40

1

2

3

4

1'2'

3'

4' 6'5'

Diagonal contains the 1D spectrum

Connections between hydrogens are

symmetrical about the diagonal

Generally, the higher the contour

the stronger the connection

3A cis-Cyclohex-4-ene-1,2-dicarboxylic Acid Anhydride



1H

13C

3A cis-Cyclohex-4-ene-1,2-dicarboxylic Acid Anhydride

Long Range CH COSY ( HMBC)

Multiple correlations of hydrogen to carbon resonances or vice versa

1H

13C

3B cis-Cyclohexane-1,2-dicarboxylic Acid Anhydride



1H

13C

Note: the CH2 signals in the edited HSQC are inverted like the DEPT 135° (i.e. colour showing the peak is different)

3B cis-Cyclohexane-1,2-dicarboxylic Acid Anhydride

Long Range CH COSY (HMBC)

Multiple correlations of hydrogens to carbon resonances

1H

13C

4 HH COSY 2,6-Dimethyl-5-hydroxyheptan-3-one

OH

O OH

1

2

3

4

5

6

7

Diagonal contains the 1D spectrum Connections between hydrogens are symmetrical about the diagonal

4 1D selective TOCSY (HH correlation) 2,6-Dimethyl-5-hydroxyheptan-3-one

Normal spectrum

Spin lock from 1.69ppm

Spin lock from 1.1ppm

1D selective TOCSY

- method of exploring separate spin systems, only linked HH correlations are

observed

- the information is the same as found in the HH COSY but at higher resolution

O OH

1

2

3

4

5

6

7

4 CH COSY (edited HSQC) 2,6-Dimethyl-5-hydroxyheptan-3-one

1H

13C

O OH

1

2

3

4

5

6

7

Methyl region

4 CH COSY (HSQC) 2,6-Dimethyl-5-hydroxy-heptan-3-one

(ppm) 2.72 2.64 2.56 2.48 2.40

(ppm)

44.8

44.0

43.2

42.4

41.6

40.8

40.0

How to define and understand obscured information in the proton spectrum

Expansion of the 2.40-2.75ppm region

CH

-CH2-

Spin-Spin Coupling information

from the CH2 (Hz)

calculate from proton spectrum

2. ?? ppm

2.??ppm

2.?? ppm

4 Long Range CH COSY (HMBC) 2,6-Dimethyl-5-hydroxyheptan-3-one

(ppm) 3.6 3.2 2.8 2.4 2.0 1.6 1.2

(ppm)

200

160

120

80

40

Notice CH correlations to :

- longer range

i.e. two or more bonds

for a CH correlation

- a carbonyl resonance

i.e. a quaternary peak

- a hydroxyl peak

Keto Carbon 216 ppm

4 Long Range CH COSY (HMBC) 2,6-Dimethyl-5-hydroxyheptan-3-one

keto carbonyl correlations to protons

Expansions of certain regions

5A CH COSY of 1-Phenyl-1,4-butanediol

HSQC

(ppm) 8.00 7.00 6.00 5.00 4.00 3.00 2.00 1.00

(ppm)

120

100

80

60

40

(ppm) 7.40 7.36 7.32 7.28 7.24

(ppm)

130.0

128.0

126.0

124.0

122.0

OH

HO1H

13C

o,m 1H signals

overlap

p

5A HH COSY of 1-Phenyl-1,4-butanediol

(ppm) 7.2 6.4 5.6 4.8 4.0 3.2 2.4 1.6

(ppm)

7.2

6.4

5.6

4.8

4.0

3.2

2.4

1.6

OH

HO

1

2

3

4

5B CH COSY -Phenyl- -butyrolactone

HSQC

(ppm) 8.00 7.00 6.00 5.00 4.00 3.00 2.00

(ppm)

140

120

100

80

60

40

(ppm) 2.80 2.60 2.40 2.20 2.00 1.80

(ppm)

36

32

28

24

(ppm) 7.68 7.60 7.52 7.44 7.36 7.28 7.20 7.12

(ppm)

130.0

128.0

126.0

124.0

122.0

OOH

4

1’

3 2

2’

6’ 4’

3’

5’

spot the overlap

6 cis-caran-trans-4-ol

The proton NMR is complex - only some features can be ascertained from the spectrum

Carbon-13 and Carbon DEPT 135° and 90° spectra provide clearer information on the

structure - match the data to the formula

The CH COSY (edited HSQC) provides the solution to the proton resonance positions

Assign most of the cyclohexyl ring structure from the HH COSY

from the Long range CH COSY (HMBC) - the ring assignment can be solved

from the NOE data a key conformational feature can be confirmed

6 CH COSY (edited HSQC) cis-caran-trans-4-ol

HCH3

OH

HH

HCH3

CH3

methyl peaks

6 HH COSY cis-caran-trans-4-ol

(ppm) 3.2 2.8 2.4 2.0 1.6 1.2 0.8

(ppm)

3.2

2.8

2.4

2.0

1.6

1.2

0.8

HCH3

OH

HH

HCH3

CH3

high contour levels - confirms the methylene proton positions

More complex NMR experiments to determine the

configuration of the cis-Caran-trans-ol

Long range CH COSY

used to find correlations to proton(s) other than those directly attached to a carbon

used to establish links to hydroxy groups and ‘quaternary’ carbon peaks

Nuclear Overhauser Effect (NOE)

This will establish interactions of the spins through SPACE 1D Selective NOE experiment – irradiate a specific proton and observe any changes

expect to differentiate between the two methyl peaks on the cyclopropyl ring

one should be lying in the same plane as the two cis protons on the ring

1D selective TOCSY - HH Correlation from a selected peak by varying the spin lock time it is possible to find directly linked spins

near and far depending on the experimental conditions

6 Long Range CH COSY (HMBC) cis-Caran-trans-4-ol

HCH3

OH

HH

HCH3CH3


Cyclopropyl CH peaks


Methyl peaks

6 1D selective NOE NMR cis-Caran-trans-4-ol

Normal spectrum

peak irradiated at 1.0ppm

peak irradiated at 0.93ppm

positive NOE

No NOE

Through space information

6 1D selective TOCSY (HH correlation) cis-Caran-trans-4-ol

Normal spectrum

Short Spin lock

Long Spin lock

1D TOCSY with short spin lock time - only certain adjacent spins observed

long spin lock time - all linked HH correlations observed

This is the same result as in HH COSY but at higher resolution

Basic IR analysis

• Aromatic C-H st 3080-3030 cm-1

-C=C- st 1600-1400 cm-1

-C-H oop 900-600 cm-1

• Alkanes C-H st 2840-3000 cm-1

-CH2- ~1460 cm-1

• Alkenes -C-H (C=C) st 3100-3000 cm-1

-C=C- st 1690-1635 cm-1 H-C (=C) oop 1000-675 cm-1

Alcohols : Aliphatic

• -OH st 3650-3200cm-1

H bonded 3550 - 3450cm-1

broad

Free OH 3650 - 3590cm-1

sharp

• -C-O-(H) 1260 - 970cm-1 strong

1° -CH2OH 1075 - 1000cm-1

2° -CH-OH 1125 - 1100cm-1

3° -C-OH 1210 - 1100cm-1

Ketones

• -C=O st 1775-1650cm-1

• Lactones -C=O st 1745 - 1650cm-1

-C-O 1330 - 1050cm-1 TWO bands, one

strong

- lactones ~1180cm-1

Acids • -COO-H st 3550-2500cm-1 broad

• -C=O 1800-1650cm-1 - aliphatic 1715cm-1

• -CO-OH oop ~920cm-1

Acid Anhydrides

• -C=O st 1870 - 1725cm-1 two bands

- Cyclic 6 membered rings ~1800cm-1 and stronger ~1760cm-1

• - CO-C st ~ 920cm-1

Halogens

Chlorine

• Aliphatic-Cl < 830cm-1 -often 500-600cm-1

Bromine

• Aliphatic-Br < 700cm-1

Some suggestions for Further Reading on NMR There are more than 250 books available in the TCD Library

• Useful introductions on NMR spectroscopy can be found in most general Organic text books

There are many other useful texts including a basic NMR text in the Oxford Chemistry Primer series (# 32) by Peter Hore

• Texts with emphasis on structural elucidation (a couple of examples here - there are many !) :

– Pretsch, E., et al ‘Tables of Spectral Data for structure Determination of Organic compounds’

Springer, 1997, 2000, 2009

– Williams, D.H., ‘Spectroscopic methods in Organic Chemistry’ MCGraw Hill 1995

– Berger S., Sicker, D., ‘Classics in Spectroscopy ’, VCH, 2009

– Field, L., Li, H, Magill, A., ‘Organic structure from 2D NMR spectroscopy’, Wiley, 2015

• Basic and mainly non-mathematical introductions to pulsed NMR techniques:

– Freeman, R., ‘ Magnetic Resonance in Chemistry and Medicine’, Oxford, 2003.

– Sanders, J.K.M., Hunter B.K., ‘Modern NMR Spectroscopy - a guide for chemists’, Oxford 1993.

– Claridge, T., ‘High Resolution NMR techniques in Organic Chemistry ’, Elsevier, 2009

– Freibolin, H., ‘Basic One- and Two-Dimensional NMR Spectroscopy’, Wiley-VCH, 1991, 2011

– Günther, H., ‘NMR Spectroscopy - basic principles, concepts and applications in chemistry’, Wiley, 1995, 2013

– Zebre, O., Jurt,S., ‘Applied NMR Spectroscopy for Chemists and Life Scientists’ Wiley 2013

– Richards, S. , Hollerton, J., ‘Essential Practical NMR for Organic Chemistry’ , Wiley, 2011

Suggested Further Reading

• Practical Experimental texts ( i.e. how to run real NMR experiments ) :

– Braun, S., Berger S., ‘200 and more basic NMR experiments’, Wiley-VCH, 2004

– Findeisen M., Berger, S., ‘50 and More Essential NMR Experiments’, Wiley-VCH, 2014

• More advanced (increasingly mathematical, i.e. quantum mechanics and all that !),

– Hore, P., Jones, J. Wimperis, S., ‘NMR : The Toolkit’, OCP 92, Oxford, 2000

– Keeler, J., ‘Understanding NMR spectroscopy’, Wiley, 2005, 2010

– Freeman, R., ‘A Handbook of Nuclear Magnetic Resonance’,2nd ed. Longman, 1997

– Freeman, R., ‘Spin Choreography, basic steps in high resolution NMR’, Spektrum, 1996

– Harris R.K., ‘Nuclear Magnetic Resonance Spectroscopy’, Longman, 1986

– Henel, J., Klinowski J., ‘Fundamentals of Nuclear Magnetic Resonance’, Longman, 1993

– Shaw, D., ‘Fourier Transform NMR Spectroscopy’, 2nd Ed. Elsevier, 1987

– Fukushima, E., Roeder S., ‘Experimental Pulse NMR a nuts and bolts approach’, Addison-Wesley, 1981

– Levitt, M.,‘Spin Dynamics, basics of Nuclear magnetic Resonance’, Wiley, 2008, 2012

– Van der Ven, F., ‘Multidimensional NMR in liquids’, VCH, 1995

– Ernst, R., Bodenhausen, G., Wokaum, A., ‘Principles of Nuclear Magnetic Resonance in One and Two dimensions’, Oxford, 1987

– Jacobsen, N.E., ‘NMR Spectroscopy Explained’, Wiley 2007

– Neuhaus, D., Williamson, M., ‘The Nuclear Overhauser Effect in structural and conformational analysis’ , 2nd ed. Wiley 2000

– Hoch, J., Stern, A., ‘ NMR data processing’, Wiley, 1996

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