Organic Chemistry - Chapter 13 NMR
Spectroscopy
On an 1H NMR spectra the number of signals shows
total number of different hydrogens
On an 1H NMR spectra the Chemical shift (position of signal) shows
the environment of each hydrogen
Deshielding
On an 1H NMR spectra the Integration of signals shows (INTENSITY)
Number of Each kind of hydrogen
On an 1H NMR spectra the splitting pattern shows
Number of neighboring distinct hydrogens
If there are 2 signals, this means
there are two groups of chemically distinct hydrogens
In H NMR Enantiomers are
equivalent
3 multiple choice options
In H NMR diastereomers (R,S) and (R,R) are
different
3 multiple choice options
A chemical shift upfield means
, It is MORE Shielded
It is more right, has a lower number
A chemical shift downfield means
It is LESS Shielded
It is more left, higher number
Everything on the 1H NMR spectra is downfield from
TMS
Chemical shift (sheilding) is affected by
electron density
The presence of electronegative atoms causes
deshielding
The more electronegative an atom,
the Larger the downfield shift
1H NMR Methyl chemical shift
about 0.9
1H NMR aldehyde chemical shift (H-C=O)
9-10 ppm
1H NMR Aromatic Ring chemical shift
7 - 8 ppm
1H NMR Alkene C=C-H chemical shift
4.5 - 6.5 ppm
1H NMR carboxylic acid chemical shift
Spectroscopy
On an 1H NMR spectra the number of signals shows
total number of different hydrogens
On an 1H NMR spectra the Chemical shift (position of signal) shows
the environment of each hydrogen
Deshielding
On an 1H NMR spectra the Integration of signals shows (INTENSITY)
Number of Each kind of hydrogen
On an 1H NMR spectra the splitting pattern shows
Number of neighboring distinct hydrogens
If there are 2 signals, this means
there are two groups of chemically distinct hydrogens
In H NMR Enantiomers are
equivalent
3 multiple choice options
In H NMR diastereomers (R,S) and (R,R) are
different
3 multiple choice options
A chemical shift upfield means
, It is MORE Shielded
It is more right, has a lower number
A chemical shift downfield means
It is LESS Shielded
It is more left, higher number
Everything on the 1H NMR spectra is downfield from
TMS
Chemical shift (sheilding) is affected by
electron density
The presence of electronegative atoms causes
deshielding
The more electronegative an atom,
the Larger the downfield shift
1H NMR Methyl chemical shift
about 0.9
1H NMR aldehyde chemical shift (H-C=O)
9-10 ppm
1H NMR Aromatic Ring chemical shift
7 - 8 ppm
1H NMR Alkene C=C-H chemical shift
4.5 - 6.5 ppm
1H NMR carboxylic acid chemical shift
