Electronic Paramagnetic Resonance (EPR) Section

This technique allows us to know, from whether an ion is in a valence with unpaired electrons, to whether the sample is constituted of a single paramagnetic compound, or also to make a detailed study to obtain symmetry information and/or the electronic distribution of a paramagnetic ion in relation to the atoms of the ligands that constitute the crystalline field seen by the ion, as usually happens with monocrystalline samples.

The same paramagnetic entity can give completely different spectra if any of the ligands are changed, which is expected for a solid sample when dissolved in different solvents.

The same paramagnetic entity can give completely different spectra if any of the ligands are changed, which is expected for a solid sample when dissolved in different solvents.

The applications of Electron Paramagnetic Resonance Spectroscopy are very diverse and extend to various fields of research in chemistry, physics, geology, medicine, etc. Due to its non-destructive nature and its high versatility, it is the ideal complement to other methods of analysis, allowing valuable structural and dynamic information to be obtained. Unlike other techniques, it can be used in the study of evolving physico-chemical processes without influencing their development.

Among its many areas of application, the following can be highlighted:

• Redox processes.
•  Polymer reactions.
• Photosynthesis.
• Relaxation phenomena.
• Semiconductors.
• Geochronology.
• Reaction kinetics.
• Enzymatic reactions.
• Radicals in living tissues.
• Phase transitions.
• Magnetic materials, etc.

In principle, the possession of a net electron spin momentum is the only necessary (and sufficient) condition that a material must fulfil in order to be studied by EPR.

Numerous systems meet this condition:

•  Free radicals in solid, liquid or gaseous state.
• Most two transition ions and rare earths.
• Defects in ionic crystals.
• Conduction electrons in semiconductors.
• Biradicals, triplet state systems, etc.