467 / 912
Chapter 14 459
Copyright © 2017 Pearson Education, Inc.
quartet
an NMR signal that is split into four equally spaced peaks with an integral ratio of
1:3:3:1.
reference compound
a compound added to the sample whose NMR spectrum is to be taken. The position
of the signals in the NMR spectrum are measured from the position of the signal
given by the reference compound.
rf radiation
radiation in the radiofrequency region of the electromagnetic spectrum.
shielding
the electrons around a proton shield the proton from the full effect of the applied
magnetic field. The more a proton is shielded, the farther to the right its signal
appears in an NMR spectrum.
singlet
an unsplit NMR signal.
spin-spin coupling
the splitting of a signal in an NMR spectrum described by the
N
+
1
rule.
A
-spin state
nuclei in this spin state have their magnetic moments oriented in the same direction
as the applied magnetic field.
B
-spin state
nuclei in this spin state have their magnetic moments oriented opposite the
direction of the applied magnetic field.
splitting diagram
a diagram that describes the splitting of a set of protons.
(splitting tree)
triplet
an NMR signal that is split into three equally spaced peaks with an integral ratio
of 1:2:1.
upfield
farther to the right-hand side of the spectrum.
X-ray crystallography
a technique used to determine the arrangement of atoms within a crystal.
X-ray diffraction
a technique used to obtain images that are used to determine the electron density
within a crystal.