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Interpreting the infrared
spectrum of methoxyethane
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Brown's Chemistry Advanced Level Pre-University Chemistry Revision Study
Notes for UK IB KS5 A/AS GCE advanced A level organic chemistry students US
K12 grade 11 grade 12 organic chemistry courses involving molecular
spectroscopy analysing infrared spectra of methoxyethane
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Infrared spectroscopy - spectra index
See also
comparing the infrared, mass, 1H NMR and 13C NMR
spectra of the 3 isomers of C3H8O
The infrared spectrum of ethoxyethane - I would expect the infrared spectrum of
methoxyethane to be similar.
Methoxyethane,
A possible interpretation of
the infrared spectrum of methoxyethane
I was unable to find an image of the infrared
spectrum of methoxyethane, but considering the infrared spectra of
methoxymethane and
ethoxyethane and data tables,
you can make some reasonable predictions as to the most prominent
absorption wavenumbers for methoxyethane.
The expected most prominent infrared absorption lines of
methoxyethane
In general for ethers, the C-H stretching vibration absorption bands are
found in the 2800 to 3000 cm-1 wavenumber region -
typical 'alkyl values' even though methoxyethane is an ether.
More specifically, the C-H stretching vibrations for
the O-CH3
group in methoxyethane occur at wavenumbers 2830 to 2815 cm-1.
In general, a group of C-O stretching absorptions, from the
ether linkage (C-O-C), are found around wavenumbers 1150 to 1060 cm-1.
more specifically, the C-O stretching vibrations for a O-CH3
group occur at wavenumbers ~1250 cm-1.
The absence of other specific functional group bands
will show that particular functional group is absent from the
methoxyethane
molecular
structure.
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Comparing the infrared, mass, 1H NMR and 13C NMR
spectra of the 3 isomers of C3H8O
NOTE: The images are linked to their
original detailed spectral analysis pages AND can be doubled in
size with touch screens to
increase the definition to the original propan-1-ol,
propan-2-ol and methoxyethane image sizes. |
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I wasn't able to obtain an infrared
spectrum for methoxyethane, so I've added the infrared spectrum
of ethoxyethane to enable a few comparisons with two aliphatic
alcohols
Comparing the
infrared
spectra of
propan-1-ol,
propan-2-ol and
methoxyethane
Propan-1-ol,
propan-2-ol and methoxyethane
are structural isomers of molecular formula C3H8O
Propan-1-ol,
propan-2-ol and methoxyethane
exemplify infrared spectra of the lower members of the homologous series
of aliphatic alcohols and ethers |
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INFRARED SPECTRA
(above): There are, as expected, differences in the fingerprint region at
wavenumbers 1500 to 400 cm-1, but most absorptions
for all three molecules are the various C-O and the many C-H
vibrational modes. However, there is one characteristic distinguishing
absorption only present in the infrared spectra of alcohols, but
not in ethers, that is the broad O-H stretching vibration
peaking at ~3350 cm-1. There is also another broad
absorption band (origin?) peaking at ~650 cm-1 in the
alcohol spectra, but not in the ether spectra. Neither of these
two bands occurs in the infrared spectrum of methoxyethane. |
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Comparing the
mass
spectra of
propan-1-ol,
propan-2-ol and
methoxyethane
Propan-1-ol,
propan-2-ol and methoxyethane
are structural isomers of molecular formula C3H8O
Propan-1-ol,
propan-2-ol and methoxyethane
exemplify the mass spectra of the lower members of the homologous series
of aliphatic alcohols and ethers |
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MASS SPECTRA (above):
The base ion peaks are m/z 45 for propan-2-ol and methoxyethane,
but that of propan-1-ol is m/z 31. Many of the fragmentation
ions are common to all three spectra. The m/z 45 ion is peak is
much smaller in the propan-1-ol spectrum compared to the other
two. |
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Comparing the
1H proton NMR
spectra of
propan-1-ol,
propan-2-ol and
methoxyethane
Propan-1-ol,
propan-2-ol and methoxyethane
are structural isomers of molecular formula C3H8O
Propan-1-ol,
propan-2-ol and methoxyethane exemplify the 1H proton NMR spectra of
the lower members of the homologous series of aliphatic alcohols and
ethers |
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1H NMR SPECTRA (above): The 1H NMR spectra of
all three molecules give different integrated proton ratios for the
different 1H chemical environments i.e. the proton
ratios are as follows: propan-1-ol
3:2:2:1; propan-2-ol 6:1:1 and methoxyethane
3:2:3. Therefore, all three can be distinguished by their
1H NMR spectra. |
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Comparing the
carbon-13 NMR
spectra of
propan-1-ol,
propan-2-ol and
methoxyethane
Propan-1-ol,
propan-2-ol and methoxyethane
are structural isomers of molecular formula C3H8O
Propan-1-ol,
propan-2-ol and methoxyethane exemplify the carbon-13 NMR spectra of
members of the lower members of the homologous series of aliphatic
alcohols and ethers |
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13C NMR SPECTRA
(above): The
13C NMR spectra of propan-1-ol and methoxyethane show
three different 13C NMR chemical shifts, but
propan-2-ol can be distinguished from the other two by
exhibiting only two chemical shift lines. You would need other
spectral data to distinguish propan-1-ol and methoxyethane. |
Key words & phrases: C3H8O CH3OCH2CH3
CH3CH2OCH3 image and diagram explaining the infrared spectrum
of methoxyethane, complete infrared absorption spectrum of methoxyethane, comparative spectra of
methoxyethane, prominent peaks/troughs for identifying functional groups in the infrared spectrum of
methoxyethane,
important wavenumber values in cm-1 for peaks/troughs in the infrared spectrum
of methoxyethane, revision of infrared spectroscopy of methoxyethane, fingerprint region analysis of
methoxyethane, how to identify methoxyethane from its infrared spectrum, identifying organic
compounds like methoxyethane from their infrared spectrum,
how to analyse the absorption bands in the infrared spectrum of methoxyethane detection of functional groups in the
methoxyethane molecule example of the infrared spectrum of a
molecule like methoxyethane with a functional group
interpreting interpretation of the infrared spectrum of methoxyethane shows presence
of functional group
for ethyl methyl ether
spectrum of methoxyethane methyl ethyl ether
CH3CH2OCH3 ethyl methyl ether.isomer of molecular formula C3H8O
Diagram of absorption of wavenumber
peaks in the infrared spectrum of methoxyethane. Characteristic peak wavenumbers in the infrared
spectrum of methoxyethane. Finger print identification pattern using the infrared
spectrum of methoxyethane. Revision notes on the infrared spectrum of
methoxyethane. Matching
and deducing the structure of the methoxyethane molecule from its infrared
spectrum. Infrared spectroscopy of aliphatic ethers, infrared spectra of
methoxyethane, an isomer of molecular formula C3H8O
Links associated with methoxyethane
Infrared spectroscopy index
The mass
spectrum of methoxyethane
The H-1
NMR spectrum of methoxyethane
The
C-13 NMR spectrum of methoxyethane
ALL SPECTROSCOPY INDEXES
All Advanced Organic
Chemistry Notes
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