Study Set Content:
in the radiofrequency region is used to excite atoms, like protons or carbon-13 atoms, so that their spins switch from being aligned with to being aligned against an applied magnetic field
Radiation
The range of frequencies required for excitation and the complex splitting patterns produced are very characteristic of the
chemical structure of the molecule.
The principle behind NMR is that many nuclei have spin and all nuclei are
electrically charged.
If an external magnetic field is applied, an energy transfer is possible between the base energy to a higher energy level (generally a ())
.single energy gap
takes place at a wavelength that corresponds to radio frequencies and when the spin returns to its base level, energy is emitted at the same frequency.
The energy transfer
The signal that matches this transfer is measured in many ways and processed in order to yield an NMR spectrum for the
nucleus concerned
Glass tube with 8.5 cm long, 0.3 cm in diameter
Sample holder
It provides a homogeneous magnetic field at 60-100 MHZ
Permanent magnet
These coils induce a magnetic field when current flows through them
Magnetic coils
To produce an equal amount of magnetic field pass through the sample
Sweep generator
A radio transmitter coil transmitter that produces a short powerful pulse of radio waves.
Radio frequency transmitter
A radio receiver coil that detects radio frequencies emitted as nuclei relax to a lower energy level
Radio frequency receiver
A computer that analyses and records data
Read out systems
TYPES OF NMR SPECTROSCOPY
1.Continuous-Wave NMR
2.Fourier-Transform NMR
3.Spin-spin Coupling
4.Carbon – 13 NMR
5.Area under Peak
