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
Experiment 1 Cis-5,5,10,10-Tetrachlorotricyclo[7.1.0.04,6]decane
On closer inspection of the carbon-13 spectrum - three additional signals are observed
What can these signals be attributed to ?
Experiment 1 Cis-5,5,10,10-Tetrachlorotricyclo[7.1.0.04,6]decane
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 2b 13C NMR (E,E)-1,4-Diphenyl-1,3-butadiene
Experiment 3a cis-Cyclohex-4-ene-1,2-dicarboxylic acid anhydride
Experiment 3a cis-Cyclohex-4-ene-1,2-dicarboxylic acid anhydride
Experiment 3b cis-Cyclohex-4-ane-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 4 2,6-Dimethyl-5-hydroxy-heptan-3-one
Experiment 5a 1-Phenyl-1,4-butanediol
Experiment 5a 1-Phenyl-1,4-butanediol
Experiment 5b -Phenyl- -butyrolactone
Experiment 5b -Phenyl- -butyrolactone
Experiment 6 (-)cis-Caran-trans-4-ol
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
CH COSY (edited HSQC)
Direct correlation of the hydrogen to carbon resonances
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
CH COSY (edited HSQC)
Direct correlation of the hydrogen to carbon resonances
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
6 Long Range CH COSY (HMBC) cis-Caran-trans-4-ol
Cyclopropyl CH peaks
6 Long Range CH COSY (HMBC) cis-Caran-trans-4-ol
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