Principle : Infrared spectroscopy is a means of characterization to determine the nature of chemical bonds present in a molecule. in fact, some vibration frequencies, called » frequency band « , are characteristics
the presence of a chemical moiety in the molecule.
The sample is subjected to a electromagnetic radiation in the wavelength range of the centre-infrared (2.5 μm < λ < 50 µm). the electric field induced by the electromagnetic wave can interact with a dipole moment of a molecular entity present in the material. when the field frequency coincides with the frequency of vibration of an eigen mode of the molecule, the interaction that is created causes the vibration of some bonds and the absorption of the energy of the wave field corresponding. the rate at which is absorbed the radiation depends on the nature of the links, the mass of the atoms involved and of the close environment of the group considered.