About NMR, Fundamental Principle and Theory, Instrumentation, Solvent, Chemical Shift, Factor Affecting Chemical Shift, Spin-spin Coupling, Application of NMR, Reference, Acknowledgment

1. NUCLEAR MAGNETIC
RESONANCE
DEPARTMENT OF CHEMISTRY,
AMRIT CAMPUS
INSTITUTE OF SCIENCE AND TECHNOLOGY
TRIBHUVAN UNIVERSITY,
KATHMANDU, NEPAL
PRESENTED BY :
GOVINDA PATHAK
ROLL NO. 305/072
T.U. REG NO.: 5-2-37-1373-2011

2. CONTENTS• INTRODUCTION
• FUNDAMENTAL PRINCIPLE AND THEORY
• INSTRUMENTATION
• SOLVENT
• CHEMICAL SHIFT
• FACTOR AFFECTING CHEMICAL SHIFT
• SPIN-SPIN COUPLING
• APPICATION OF NMR
• REFERENCE
• ACKNOWLEGEMENT

3. INTRODUCTION
Nuclear magnetic resonance is a powerful analytical technique used
to characterize organic molecules by identifying carbon-hydrogen
framework within molecules.
Based on absorption of electromagnetic radiation and utilize radio
frequency 4 to 900mhz by nuclei.
It is used to study variety of nuclei
1H
13C
15N
31P
19F

4. TYPES OF NMR
Two types of NMR spectroscopy are used to characterize organic
structure.
• 1H-NMR used to determine the type and number of H-atom.
• 13C-NMR used to determine type of carbon atoms in the
molecules.

5. PRINCIPAL OF NMR
The theory behind NMR comes from
spin of nucleus and it generates
magnetic field without applying
external magnetic field. In absence
of external magnetic field nuclear
spin arranged random in direction.
When external magnetic field
applied the nuclei spin of atom
arrange themselves either with or

6. If external magnetic field applied energy transfer (ΔE) is possible
between ground state to excited state.
When spin returns to its ground state the absorb radio frequency is
emitted at same frequency level which provide valuable
information.

7. Resonance : When the frequency of oscillating electric field
component of incoming radiation just matches the frequency of
electric field generated by the precessing nucleus, the two fields can
couple and energy can be transferred from the incoming radiation
to nucleus to flip its spin, is called resonance. Moreover we can say
that nucleus is said to have resonance with the incoming
electromagnetic wave.

8. NMR SPECTRUM OF ETHYL BENZENE AND
TOLUENE

9. NMR
MACHINE

10. NMR INSTRUMENTATION
1. SAMPLE HOLDER
2. PERMANENT MAGNET
3. MAGNETIC COILS
4. RADIO FREQUENCY
TRANSMITTER
5. RADIO FREQUENCY
RECIEVER
6. READOUT SYSTEM

11. 1. Sample holder :- Glass tube with 8.5 cm long, 0.3 cm in diameter
2. Permanent magnet :- It provides homogeneous magnetic field at
60-100 MHz
3. Magnetic coils :- These coils induce magnetic field when current
flows through them .
4. Sweep generator :- To produce the equal amount of magnetic
field pass through the sample
5. Radio frequency :- A radio transmitter coil transmitter that
produces a short powerful pulse of radio waves
6. Radio frequency reciever :- A radio receiver coil that detects
receiver radio frequencies emitted as nuclei relax to a lower
energy level
7. Readout system :- A computer that analyses and record the data

12. SOLVENT USED IN NMR
FOLLOWING SOLVENTS ARE NORMALLY USED
Carbon Tetrachloride(CCL4)
Carbon Disulfide ( CS2 )
Deutero Chloroform ( CHCL3 )
Hexadeutero Benzene (C6D6)
Deuterium Oxide(D2O)

13. CHEMICAL SHIFT
The shift in position of NMR region resulting from shielding and
deshielding by electron is called chemical shift.
When proton is present inside magnetic field more close to
electropositive atom more applied magnetic field required to
cause excitation. This effect is called shielding effect.
If proton is present inside magnetic field more close to
electromagnetic atom less applied magnetic field is required called
deshielding effect.
The chemical shift is dimension less is expressed in ppm.
Most of chemical shift value lies from 0-10ppm.
Chemical shift is measured by taking reference TMS.

14. FACTORS AFFECTING CHEMICAL SHIFT
CHEMICAL SHIFT DEPENDS UPON FOLLOWING
1. Inductive Effect
2. Hybridization
3. Anisotropic Effect
4. Hydrogen Bonding

15. SPIN-SPIN COUPLING(SPLITTING)
• The interaction between the spin of neighboring nuclei in molecule
may cause splitting in NMR spectrum. This is called splitting of
NMR.
• Chemically equivalent proton do not show spin-spin coupling due
to interaction among themselves, thus only non-equivalent proton
show the property of coupling.
• Proton on adjacent carbon normally will couple.
• Proton separated by four or more bond will not couple.

16. APPLICATION OF NMR
It is used in chemistry to determine enantiomeric purity, elucidate
chemical structure of organic and inorganic compound
macromolecules ligand interaction.
It provide(C-H) framework of different organic compound
important for structure determination.
It is used in pharmaceutical industry and drugs metabolism.
NMR is used in physics and physical chemistry to study high
pressure diffusion, liquid crystal, liquid crystal solution,
membranes , rigid solids .

17. REFERENCES
Organic Spectroscopy By William Kemp
Instrumental Methods Of Chemical Analysis By Chatwal
Instrumental Methods Of Analysis By Willard
Wikipedia.Org
E. Fukushima and S.B.W. Roeder, Experimental Pulse NMR,
Addison-Wesley, Reading, MA 1981.
T.C. Farrar, An Introduction To Pulse NMR Spectroscopy, Farragut
Press, Chicago, 1987.
R.C. Jennison, Fourier Transforms and Convolutions, Pergamon
Press, NY 1961.
E. O. Brigham, The Fast Fourier Transform, Prentice-Hall,
Englewood Cliffs, NJ 1974.

18. ACKNOWLEDGMENTS
Head Of Department (HOD)- Associated Prof. Manju Panth Sharma
M.Sc. Coordinator- Associated Prof. Kiran Bahadur Bajrachrya Sir
Supervisor- Assistant Prof. Bhisma Raj Pandey
Respected teachers : Dr. Bhushan Shakya, Ishwor Pathak, Kamal Sapkota, Dr.
Ram Lal Shrestha
Family, Friends And All Teaching And Non-teaching Faculty Of Our
Department.

19. THANK YOU