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458 Chapter 14
Copyright © 2017 Pearson Education, Inc.
geminal coupling
the mutual splitting of two nonidentical protons bonded to the same carbon.
gyromagnetic ratio
the ratio of the magnetic moment of a rotating charged particle to its angular
momentum.
HETCOR spectrum
a 2-D NMR spectrum showing
13
C
@
1
H
correlations.
high-resolution NMR
NMR spectroscopy that uses a spectrometer with a high operating frequency.
spectroscopy
1
H
NMR
nuclear magnetic resonance from hydrogen nuclei.
long-range coupling
splitting by a proton more than three
s
bonds away.
magnetic resonance
NMR used in medicine. The difference in the way water is bound in different
imaging (MRI)
tissues produces the signal variation between organs as well as between healthy
and diseased states.
methine hydrogen
a tertiary hydrogen.
MRI scanner
an NMR spectrometer used in medicine for whole-body NMR.
multiplet
an NMR signal split by two (or more) nonequivalent sets of protons.
multiplicity
the number of peaks in an NMR signal.
N
+
1
rule
a rule that states that an
1
H
NMR signal for a hydrogen with
N
equivalent hydro-
gens bonded to an adjacent carbon is split into
N
+
1
peaks; a proton-coupled
13
C
NMR signal for a carbon bonded to
N
hydrogens is split into
N
+
1
peaks.
NMR spectroscopy
the absorption of rf radiation by nuclei in an applied magnetic field to determine
the structural features of an organic compound. In the case of
1
H
NMR spectros-
copy, it reveals the carbon–hydrogen framework.
operating frequency
the frequency at which an NMR spectrometer operates.
prochiral carbon
a carbon (bonded to two hydrogens) that will become an asymmetric center if one
of the hydrogens is replaced by deuterium.
pro-
R
-hydrogen
replacing this hydrogen with deuterium creates an asymmetric center with the
R
configuration.
pro-
S
-hydrogen
replacing this hydrogen with deuterium creates an asymmetric center with the
S
configuration.
proton-coupled
a
13
C
NMR spectrum in which each signal for a carbon is split by the hydrogens
13
C
NMR spectrum
bonded to that carbon.
proton exchange
the transfer of a proton from one molecule to another.