|
Interpreting
and explaining the
H-1 hydrogen-1 (proton) NMR spectrum of 2-iodopropane
[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 analysis of
2-iodopropane
(1H NMR spectra)
[spectra
page updated
April 1st 2026 *]
email doc
brown
Re-edit
1H NMR spectrum of CH3CHICH3
or (CH3)2CHI
Links associated with
2-iodopropane
* [privacy policy, cookies
and disclaimer]
This is a BIG
chemistry website, PLEASE take time to explore it
H-1 proton NMR spectroscopy -
spectra index
Introductory note on the 1H NMR spectra of 2-iodopropane
Students and teachers please note my explanation of the
proton NMR spectrum of 2-iodopropane is designed for advanced, but
pre-university, chemistry courses.
The chemical shift
δ splitting pattern effects for
2-iodopropane 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
2-iodopropane 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 2-iodopropane molecule.
The most common solvent used for investigating the 1H NMR
spectrum of compounds like 2-iodopropane, 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 - 2-iodopropane here.
The chemical shifts quoted in ppm on the diagram of
the H-1 NMR spectrum of 2-iodopropane 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 2-iodopropane molecule.
2-iodopropane,
C3H7I,
CH3CHICH3,
CH3-CHI-CH3
The molecular structure and naming of haloalkanes
Interpreting the
H-1 NMR spectrum of
2-iodopropane
In terms of spin-spin coupling from the possible proton magnetic orientations,
for 2-iodopropane I
have only considered the interactions of
non-equivalent protons on adjacent carbon atoms
e.g. -CH-CH3
protons.
For relatively simple molecules, the low
resolution H-1 NMR spectrum of 2-iodopropane is a good starting point
(low resolution diagram above).
The 7 hydrogen atoms (protons) of 2-iodopropane occupy
2
different chemical environments so that the low resolution NMR
spectra should show
2 principal
1H peaks of different H-1 NMR chemical shifts (diagram above for
2-iodopropane).
CH3-CHI-CH3
Note the proton ratio 6:1 of the 2 colours of the
7 protons of 2-iodopropane
in the 2 chemically different proton environments
Chemical shifts (a) to (b) on the H-1 NMR
spectrum diagram for 2-iodopropane.
Although there are 7 hydrogen atoms in the molecule, the
proton NMR spectrum shows there are only 2 possible different chemical
environments for the hydrogen atoms in 2-iodopropane molecule.
The integrated signal proton ratio 6:1 observed
in the high resolution H-1 NMR spectrum, corresponds with
the structural formula of 2-iodopropane.
The high resolution 1H NMR
spectrum of 2-iodopropane
The high resolution spectra of 2-iodopropane
also
shows 2 groups of proton resonances and in the 6:1 ratio expected from the
structural
formula of 2-iodopropane, but we can now consider the splitting of
resonance lines from the spin-spin coupling in the molecule of
2-iodopropane.
The ppm quoted on the diagram represent the peak
of resonance intensity for a particular proton group in the
molecule of 2-iodopropane - 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 2-iodopropane below.
So, using the chemical shifts and applying the
n+1 rule to
2-iodopropane
and make some predictions using some colour coding! (In problem
solving you work the other way round!)
1H NMR resonance
(a) 1H Chemical shift 1.47 ppm, methyl group
protons: CH3-CHI-CH3
This 1H NMR resonance is split into a
1:1 doublet by the CH group proton (n+1 = 2).
Evidence for the presence of a CH group
in the molecule of 2-iodopropane
1H NMR resonance
(b) 1H Chemical shift 3.80 ppm, CH group proton: CH3-CHI-CH3
This 1H NMR resonance is split into a
1:6:15:20:15:6:1 septet by the CH3 group
protons on either side. (n+1 = 7).
Evidence for the presence of a CH3-CHx-CH3 group
in the molecule of 2-iodopropane, x can be 2 or 1, as in
the case of 2-iodopropane.
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
2-iodopropane.
|
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:
C3H7I
CH3CHICH3 Interpreting the proton H-1 NMR spectra of 2-iodopropane, low resolution & high resolution proton
nmr spectra of 2-iodopropane, H-1 nmr spectrum of 2-iodopropane, understanding the
hydrogen-1 nmr spectrum of 2-iodopropane, explaining the line splitting patterns from
spin-spin coupling in the
high resolution H-1 nmr spectra of 2-iodopropane, revising the H-1 nmr spectrum of
2-iodopropane,
proton nmr of 2-iodopropane, ppm chemical shifts of the H-1 nmr spectrum of
2-iodopropane,
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 2-iodopropane, how to work out the
number of chemically different protons in the structure of the 2-iodopropane organic
molecule, how to analyse the chemical shifts in the hydrogen-1 H-1 proton NMR
spectrum of 2-iodopropane using the n+1 rule to explain the spin - spin coupling ine
splitting in the proton nmr spectrum of 2-iodopropane deducing the nature of the protons
from the chemical shifts ppm in the H-1 nmr spectrum of 2-iodopropane
examining the 1H nmr spectrum of 2-iodopropane analysing the 1-H nmr spectrum of
2-iodopropane
how do you sketch and interpret the H-1 NMR spectrum of 2-iodopropane
interpreting interpretation of the 1H proton spin-spin coupling causing line
splitting in the NMR spectrum of 2-iodopropane
assignment of chemical shifts in the
proton 1H NMR spectrum of 2-iodopropane formula explaining spin-spin coupling
for line splitting for 2-iodopropane
isopropyl iodide alkyl halide
functional group haloalkane halogenoalkane
iodoalkane How do you interpret the H-1 NMR spectrum of
2-iodopropane How to interpret
the H-1 NMR spectrum of 2-iodopropane Explanatory diagram of the chemical
shifts of the 1H H-1 proton NMR spectrum of the 2-iodopropane
molecule in terms of its molecular structure. Listing data of all the chemical shift peaks in ppm in the
proton NMR spectrum of 2-iodopropane. How to explain the H-1 NMR spectrum of
2-iodopropane. The chemical shifts and integrated values of the proton ratios in the 1-H NMR
spectrum of the 2-iodopropane molecule. How to work out the molecular
structure of the 2-iodopropane molecule from its proton NMR spectrum. The uses
and distinctive features of the proton NMR spectrum of the
2-iodopropane
molecule explained. What does the H-1 proton NMR spectrum chemical
shifts tell us about the
structure and properties of the 2-iodopropane
molecule? explaining the spin-spin proton coupling effects in the 1H
NMR spectrum of 2-iodopropane. 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 2-iodopropane
Links associated
with
2-iodopropane
The chemistry of HALOGENOALKANES (haloalkanes)
revision notes INDEX
The infrared spectrum of 2-iodopropane
(isopropyl iodide)
The mass
spectrum of 2-iodopropane (isopropyl iodide)
The
C-13 NMR spectrum of 2-iodopropane (isopropyl iodide)
H-1 proton NMR spectroscopy index
(Please
read 8 points at the top of the 1H NMR index page)
ALL SPECTROSCOPY INDEXES
All Advanced Organic
Chemistry Notes
Use My Google search site box
Email doc b:
chem55555@hotmail.com
Website content © Dr
Phil Brown 2000+. All copyrights reserved on revision notes, images,
quizzes, worksheets etc. Copying of Doc Brown's pre-university
advanced level chemistry website material is NOT
permitted. Exam revision summaries & references to science course specifications
are unofficial. These organic chemistry revision notes on
spectroscopy (on the 1H NMR spectrum of 2-iodopropane) are
suitable for use of pre-university students studying AQA advanced level
chemistry, Edexcel advanced level chemistry, OCR advanced level
chemistry, IB advanced level chemistry, WJEC (Eduqas) advanced level
chemistry, CIE advanced level chemistry, CCEA advanced level chemistry, US grade 11-12 AP honors
chemistry courses and they will also prove useful to
1st year undergraduate students of chemistry. |
