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Interpreting
and explaining the
H-1 hydrogen-1 (proton) NMR spectrum of propan-2-amine
(2-aminopropane, 2-propanamine, 2-propylamine, isopropylamine)
[Author
©
Dr Phil Brown PhD:
Doc Brown's advanced level organic chemistry exam revision notes
suitable for students of UK A level chemistry courses & US K12 grade
11, grade 12 and AP honors chemistry courses: Molecular
spectroscopy - analysing the 1H NMR spectra of
propan-2-amine (isopropylamine)
[spectra
page updated
April 4th 2026 *]
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Re-edit 1H NMR spectrum of
C3H9N
CH3CH(NH2)CH3
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H-1 proton NMR spectroscopy -
spectra index
Introductory note on the 1H NMR spectra of propan-2-amine
Students and teachers please note my explanation of the
proton NMR spectrum of propan-2-amine is designed for advanced, but
pre-university, chemistry courses.
The chemical shift
δ splitting pattern effects for
propan-2-amine are
confined to a proton spin-spin
coupling effects analysed using the n+1 rule for adjacent
non-equivalent proton fields (n is the number of neighbouring
protons in a non-equivalent different chemical environment for the
propan-2-amine molecule).
It is assumed that the integrated intensities of the
δ
chemical shifts give the ratio of the protons in the different
non-equivalent chemical environments of the propan-2-amine molecule.
The most common solvent used for investigating the 1H NMR
spectrum of compounds like propan-2-amine, is CDCl3 and other
deuterated solvents to avoid confusion with a 1H NMR
signal, 2D (2H) has a different chemical
shift.
TMS is the acronym for tetramethylsilane, formula Si(CH3)4,
whose protons are arbitrarily given a chemical shift of 0.0 ppm.
This is the 'standard' in 1H NMR spectroscopy and all
other proton resonances, called chemical shifts, are measured
with respect to the TMS, and depend on the
individual (electronic) chemical environment of the hydrogen atoms
in an organic molecule - propan-2-amine (2-aminopropane) here.
The chemical shifts quoted in ppm on the diagram of
the H-1 NMR spectrum of propan-2-amine (2-aminopropane) represent the peaks of the intensity of
the chemical shifts of (which are often groups of split lines at
high resolution) AND the relative integrated areas under the peaks
gives you the ratio of protons in the different chemical
environments of the propan-2-amine (2-aminopropane) molecule.
propan-2-amine, 2-aminopropane, 2-propylamine,
2-propanamine,
isopropylamine,
The classification,
structure and naming of
organic nitrogen compounds
Interpreting the
H-1 NMR spectrum of
propan-2-amine (2-aminopropane)
In terms of spin-spin coupling from the possible proton magnetic orientations,
for propan-2-amine (2-aminopropane) I
have only considered the interactions of
non-equivalent protons on adjacent carbon atoms
e.g. -CH-CH3
protons (but see note on problems with N-H proton resonance).
For relatively simple molecules, the low
resolution H-1 NMR spectrum of propan-2-amine
(2-aminopropane) is a good starting point
(low resolution diagram above).
The hydrogen atoms (protons) of propan-2-amine
(2-aminopropane) occupy
3
different chemical environments so that the low resolution NMR
spectra should show 3 principal
1H peaks of different H-1 NMR
chemical shifts (diagram above for propan-2-amine
(2-aminopropane) in the ratio 6:1:2
(CH3)2CHNH2
Note the proton ratio 6:1:2 of the 3 colours of the
9 protons of propan-2-amine (2-aminopropane)
in the 3 chemically different proton environments
Chemical shifts (a) to (c) on the H-1 NMR
spectrum diagram for propan-2-amine (2-aminopropane).
Although there are 9 hydrogen atoms in the molecule,
there are only 3 possible different chemical
environments for the hydrogen atoms in propan-2-amine (2-aminopropane) molecule.
The integrated signal proton ratio 6:1:2 observed
in the high resolution H-1 NMR spectrum, corresponds with
the structural formula of propan-2-amine (2-aminopropane).
The high resolution 1H NMR
spectrum of propan-2-amine (2-aminopropane)
The high resolution spectra of propan-2-amine
(2-aminopropane)
shows 3 groups of proton resonances and in the 6:1:2 ratio expected from the
structural
formula of propan-2-amine (2-aminopropane).
The ppm quoted on the diagram represent the peak
of resonance intensity for a particular proton group in the
molecule of propan-2-amine (2-aminopropane) - since the peak' is at the apex of a band of
H-1 NMR resonances due to spin - spin coupling field splitting effects - see high resolution
notes on propan-2-amine (2-aminopropane) below.
So, using the chemical shifts and applying the
n+1 rule to
propan-2-amine (2-aminopropane)
and make some predictions using some colour coding! (In problem
solving you work the other way round!)
(a) 1H
Chemical shift 1.07 ppm, methyl protons: (CH3)2CHNH2
This resonance is split into a 1:1
doublet by the CH proton (n+1 = 2).
All six protons are equivalent to each
other.
Evidence for the presence of a CH group
in the molecule of propan-2-amine (2-aminopropane)
(b) 1H
Chemical shift 3.10 ppm, CH group proton: (CH3)2CHNH2
This resonance is split into a
1:6:15:20:15:6:1 septet by the methyl group protons (n+1
= 7), the amine group protons do not normally cause
splitting.
Evidence for the presence of a CH3-CHx-CH3 grouping
in the molecule of propan-2-amine (2-aminopropane)
(c) 1H
Chemical shift 1.22 ppm, amine group protons: (CH3)2CHNH2
This resonance appears a singlet because
amine proton resonances are not usually split by
adjacent C-H protons.
The splitting pattern from proton
spin-spin coupling effects is analysed using the n+1 rule for
adjacent non-equivalent proton fields (n is the number of
neighbouring protons in a non-equivalent different chemical
environment) and applied to the 1H NMR spectrum of
propan-2-amine.
|
Number of directly adjacent protons 1H
causing splitting |
Splitting pattern produced from the
n+1 rule on spin-spin coupling and the theoretical ratio of line intensities |
|
0
means no splitting |
|
|
|
|
|
|
1 |
|
|
|
|
|
|
|
1
creates a doublet |
|
|
|
|
|
1 |
|
1 |
|
|
|
|
|
|
2
creates a triplet |
|
|
|
|
1 |
|
2 |
|
1 |
|
|
|
|
|
3
creates a quartet |
|
|
|
1 |
|
3 |
|
3 |
|
1 |
|
|
|
|
4
creates a quintet |
|
|
1 |
|
4 |
|
6 |
|
4 |
|
1 |
|
|
|
5
creates a sextet |
|
1 |
|
5 |
|
10 |
|
10 |
|
5 |
|
1 |
|
|
6
creates a septet |
1 |
|
6 |
|
15 |
|
20 |
|
15 |
|
6 |
|
1 |
Key words & phrases:
isomer
of C3H9N (CH3)2CHNH2 Interpreting the proton H-1 NMR spectra of propan-2-amine
(2-aminopropane), low resolution & high resolution proton
nmr spectra of propan-2-amine (2-aminopropane), H-1 nmr spectrum of
propan-2-amine (2-aminopropane), understanding the
hydrogen-1 nmr spectrum of propan-2-amine (2-aminopropane), explaining the line splitting patterns from
spin-spin coupling in the
high resolution H-1 nmr spectra of propan-2-amine (2-aminopropane), revising the H-1 nmr spectrum of
propan-2-amine (2-aminopropane),
proton nmr of propan-2-amine (2-aminopropane), ppm chemical shifts of the H-1 nmr spectrum of
propan-2-amine (2-aminopropane),
explaining and analyzing spin spin line splitting in the H-1 nmr spectrum, how
to construct the diagram of the H-1 nmr spectrum of propan-2-amine
(2-aminopropane), how to work out the
number of chemically different protons in the structure of the propan-2-amine
(2-aminopropane) organic
molecule, how to analyse the chemical shifts in the hydrogen-1 H-1 proton NMR
spectrum of propan-2-amine (2-aminopropane) using the n+1 rule to explain the spin - spin coupling ine
splitting in the proton nmr spectrum of propan-2-amine (2-aminopropane) deducing the nature of the protons
from the chemical shifts ppm in the H-1 nmr spectrum of propan-2-amine
(2-aminopropane)
examining the 1H nmr spectrum of propan-2-amine (2-aminopropane) analysing the 1-H nmr spectrum of
propan-2-amine (2-aminopropane)
how do you sketch and interpret the H-1 NMR spectrum of propan-2-amine
(2-aminopropane) interpreting interpretation of the 1H proton spin-spin coupling
causing line splitting in the NMR spectrum of propan-2-amine (2-aminopropane)
assignment of chemical shifts in the
proton 1H NMR spectrum of propan-2-amine (2-aminopropane) formula explaining
spin-spin coupling for line splitting for propan-2-amine (2-aminopropane) old names
functional group primary aliphatic amine isopropylamine 2-propylamine
2-propanamine How do you interpret the H-1 NMR spectrum of
propan-2-amine How to interpret
the H-1 NMR spectrum of propan-2-amine Explanatory diagram of the chemical
shifts of the 1H H-1 proton NMR spectrum of the propan-2-amine
molecule in terms of its molecular structure. Listing data of all the chemical shift peaks in ppm in the
proton NMR spectrum of propan-2-amine. How to explain the H-1 NMR spectrum of
propan-2-amine. The chemical shifts and integrated values of the proton ratios in the 1-H NMR
spectrum of the propan-2-amine molecule. How to work out the molecular
structure of the propan-2-amine molecule from its proton NMR spectrum. The uses
and distinctive features of the proton NMR spectrum of the
propan-2-amine
molecule explained. What does the H-1 proton NMR spectrum chemical
shifts tell us about the
structure and properties of the propan-2-amine
molecule? explaining the spin-spin proton coupling effects in the 1H
NMR spectrum of propan-2-amine. interpretation
diagram explaining the proton splitting pattern produced from the
n+1 rule and the theoretical ratio of chemical shift
δ and values of
intensities for the proton NMR spectrum lines of propan-2-amine
Links associated
with
propan-2-amine (2-aminopropane)
The infrared spectra of
propan-2-amine (2-aminopropane, 2-propylamine, isopropylamine)
The mass
spectra of propan-2-amine (2-aminopropane,
2-propylamine, isopropylamine)
The C-13 NMR
spectra of propan-2-amine (2-aminopropane, 2-propylamine,
isopropylamine)
The chemistry of ORGANIC NITROGEN COMPOUNDS revision notes INDEX
H-1 proton NMR spectroscopy index
(Please
read 8 points at the top of the 1H NMR index page)
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spectroscopy (1H NMR spectra of
propan-2-amine, 2-aminopropane, 2-propylamine,
2-propanamine, isopropylamine)
are
suitable for use of pre-university students studying AQA advanced level
chemistry, Edexcel advanced level chemistry, OCR advanced level
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