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105 Lecture 4
Nuclear Magnetic Resonance
5
Chemistry
Undergraduate 1
05/10/2013

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Term
what does nuclear magnetic resonance spectroscopy give information on?
Definition

the structure of molecules in solution



it is an extremely powerful technique for characterisation. It is useful for simple organic compunds and large macromolecules

Term
when did High resolution Fourier Transform NMR spectrometers become available?
Definition

in the 1970's

 

 

the growth and application of FT-NMR techniques continues today

 

eg Magnetic resonance Imaging (MRI)

 

these are tomographic images using NMR methods

Term
what did Bloch and Purcell first demonstrate about certain Hydrogen nuclei absorbing and emmiting radiation?
Definition
they demonstrated that certain nuclei eg 1H will absorb and then emit electromagnetic radiation in the radio-frequency range WHEN placed in a strong magnetic field
Term
name the four basic steps of an FT-NMR experiment
Definition
  1. Place sample in strong and uniform magnetic field
  2. Tune radiofrequency source to correct frequency band for type of nucleus eg 1H or 13C
  3. Excited nuclei by broad-band RF pulses
  4. Record RF the sample emits after each pulse
Term
why is the sample spun at ~20Hz?
Definition
to reduce any effects due to inhomogeneity
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