Nmr Spectroscopy Essay
By definition, NMR spectroscopy is a research technique that makes use of the fact that certain atomic nuclei exhibit magnetic property to determine their chemical and physical properties for various uses that we’ll discuss later.
History of NMR Spectroscopy
Year Individual Discovery
1921 Stern and Gerlach Basis of quantum theory is confirmed by carrying out atomic and molecular beam experiments
1925 Ulhenbeck & Goudsmith Discovered the concept of spinning electron to the magnetic dipole moment.
1938 Isidor Rabi Described Nuclear Magnetic Resonance in molecular beams
1943 Stern Nobel prize – Discovery of magnetic momentum of the proton
1944 Isidor Rabi Nobel Prize- Discovery of resonance method
1952 Bloch …show more content…
When this transfer takes place at a particular wavelength its corresponding radio frequency is recorded, and when the spin returns to its base level, energy is emitted at the same frequency. The signal that matches this transfer is measured and examined in order to yield an NMR spectrum for the nucleus in question. The spinning nucleus has a magnetic moment whose relative values along with the angular momentum helps us to find the frequency at which energy can be absorbed. HOW DOES A NMR MACHINE WORK?
What does it consist?
1. A powerful super cooled magnet (stable, with sensitive control, which produces a precise magnetic field)
2. A radio frequency emitter
3. A detector to measure the absorption of radio frequency by the sample.
4. A pulse programmer and a computer which can process and present the whole data. The sample to be analyzed is dissolved in a solvent and placed in a magnetic field. The most used solvent for NMR spectroscopy is Chloroform-d (CDCl3) because
A. Its solubilising character is very strong.
B. It has a relatively non-reactive