Nuclear magnetic resonance spectroscopy is a powerful analytical technique used to characterize organic molecules by identifying carbon-hydrogen frameworks within molecules. • Two common types of NMR spectroscopy are used to characterize organic structure: 1H NMR is used to determine the type and number of H atoms in a molecule; C13NMR is used to determine the type of carbon atoms in the molecule. Introduction to 1H-NMR Spectroscopy

1. Republic of Iraq
Ministry of Higher Education
and scientific research
kerbala University
college of science
Department of chemistry
‫المغناطيسي‬ ‫النووي‬ ‫الرنين‬ ‫بواسطة‬ ‫العضوية‬ ‫المركبات‬ ‫تشخيص‬
‫تقديم‬
1
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‫م‬
.
‫م‬
.
‫شريف‬ ‫كاظم‬ ‫نصير‬
2
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‫م‬
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‫م‬
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‫راضي‬ ‫مقصد‬ ‫ساجد‬
( 2022A.D)

2. 
• Nuclear magnetic resonance spectroscopy is a
powerful analytical technique used to characterize
organic molecules by identifying carbon-hydrogen
frameworks within molecules.

• Two common types of NMR spectroscopy are used
to characterize organic structure: 1H NMR is used to
determine the type and number of H atoms in a
molecule; C13NMR is used to determine the type of
carbon atoms in the molecule.
Introduction to 1H-NMR
Spectroscopy

3. • The source of energy in NMR is radio waves which have long
wavelengths, and thus low energy and frequency.
• When low-energy radio waves interact with a molecule, they can
change the nuclear spins of some elements, including 1H andC13 .
• Normally, these tiny bar magnets are randomly oriented in space.
However, in the presence of a magnetic field B0, they are oriented
with or against this applied field. More nuclei are oriented with the
applied field because this arrangement is lower in energy.
.

4. • The energy difference between these two states is very small (<0.1)
Nuclear spins are oriented randomly in the absence of an external magnetic fieled (b)
have specific orientation in the presence of external field B0.Some of the spins (red)
parallel to the external field .

5. The energy difference ΔE between nuclear spins state depends on the
strength of the magnetic field.Absorption of the energy with frequency
ν converts nucleus from alower spin state to the higher spins.(a)spin
state in the absence of the (b) have anequal energy in the presence of
magnetic field at ν=200Mhz ,ΔE=0.00008 Kj/mole( C)The energy
difference between spin states is greater at ν=500MHZ. ΔE=0.0002
Kj/mole

6. Diagram of spectrum regions

7. Who response molecules for this
prperty?

Certain nuclei, such as 1H, 13C, 15N, 19F, and 31P, have a nonzero
value for their spin quantum number; this property allows them to
be studied by NMR.

8. NMR Active Nuclei?
nuclear spin quantum number (I) atomic mass and atomic
number.
Number of spin states = 2I + 1 (number of possible energy
levels)
Even mass nuclei that have even number of neutron have I
= 0
Even mass nuclei that have odd number of neutrons have
an integer spin quantum number (I = 1, 2, 3, etc)
Odd mass nuclei have half-integer spin quantum number (I
= 1/2, 3/2, 5/2, etc)
I= 1/2: 1H, 13C, 19F, 31P
I= 1: 2H, 14N
I= 3/2: 15N
I= 0: 12C, 16O

9. Schematic operation of a basic NMR spectrometer. A thin glass
tube containing the sample solution is placed between the poles
of a strong magnet and irradiated with rf energy
The sample is dissolved in CCl4 or CDCl3 or C6D6 other wise D2O

10. • Thus, two variables characterize NMR: an applied magnetic field
B0, the strength of which is measured in (gauss), and the frequency ν
of radiation used for resonance, measured in hertz (Hz), or megahertz
(MHz)— (1 MHz =106 Hz).
• NMR spectrometers are referred to as 300 MHz instruments, 500 MHz instruments,
and so forth, depending on the frequency of the RF radiation used for resonance.
At rsonance
ɣ=
2πν
Beff

12. All the Hydrogens in a Compound Do Not Experience
the Same Magnetic Field
The electrons surrounding the nucleus decrease the
effective applied magnetic field sensed by the nucleus.

13. 1H NMR Spectra
• An NMR spectrum is a plot of the intensity of a peak
against its chemical shift, measured in parts per
million (ppm).
• Chemical shift: the exact field strength (in ppm) of a
nuclei comes into resonance relative to a reference
standard (TMS).
Tetramethylsilane (TMS)
Reference standard = 0 for 1H NMR

30. Application of 1H-nmr

used to identify and quantify the
different metabolites present in the
sample

31. 1H NMR spectrum showing the main metabolites. The existence of NMR
databases of metabolites can greatly facilitate the latter processes.

32. Applications of 1H NMR spectroscopy in clinical
microbiology

This technique has also been applied for
antimicrobial drug susceptibility studies on different
species of yeast, and in the last few years, it has also
been developed for bacterial studies. Furthermore,
other determinations directly in body fluids have
emerged to help in the diagnosis of different
diseases and conditions.

33. Applications in biofluids

the last few years, 1H NMR has been used to
directly analyse biofluids and to diagnose different
diseases directly from body fluids. In this sense, it
has been applied to analyse human microbiota
from faeces and urine samples, to study the
metabolic implications that take place in sepsis, or
even to diagnose hepatitis C virus infection,
distinguish HIV‐1 positive patients from negative
individuals or to diagnose pneumonia from urine

34. Observable 1H Metabolites

35. NMR Spectroscopy: monitoring neuronal and axonal
integrity in vivo

36. Magnetic Resonance Imaging (MRI): uses the
principles of nuclear magnetic resonance to
image tissue