EPR / ESR Spectra Samples
EPR (Electron Paramagnetic Resonance) or ESR (Electron Spin Resonance)
EPR (Electron Paramagnetic Resonance) or ESR (Electron Spin Resonance) technique measures microwave frequency absorption by the EPR active free radical or paramagnetic metal ion containing molecule or any molecular species including atomic or molecular fragments, for example:
- Hydrogen atom (H)
- Hydroxyl radical (OH)
- Ferric ion (Fe3+)
- Manganese ion (Mn2+)
when placed in high magnetic field. The molecular or atomic species are ‘EPR Active’ when they possess one or more unpaired electrons and therefore, have electron ‘SPIN’ or ‘electron spin angular momentum’ -(S).
In other words, the material must have electron spin angular momentum for it to show an EPR spectrum. For example, the hydrogen atom has 1 unpaired electron that, combined with the proton nucleus (H-1, SPIN=1/2), will show a simple 2-line EPR spectrum.
These materials with electron spins are called “Paramagnetic” materials. NMR measurement on these samples will give either undetectable or broad and shifted peaks.
Therefore, EPR measurement is needed and will provide structural identification, quantification and information about the nature of the materials. There are many stable free radicals and paramagnetic compounds that are important in chemistry, materials and active pharmaceutical ingredients.
We specialize in both solution and solid-state EPR Analysis of a variety of stable organic and inorganic samples:
- Metal ions
- Solar cell materials
- Defect densities including many free radicals
- Metal ion complexes
Choose from our list of common samples we routinely conduct EPR/ESR on to see their corresponding sample EPR/ESR spectra:
EPR Spectra of Most Common Samples : | ||
Diphenyl Picryl Hydrazyl (DPPH) Free radical Solid powder (296 K) | Ferric Sucrose Complex Solid powder (296 K) | Ferric Sucrose Complex Aqueous Solution (296 K) |
Copper (II) Aquo Complex (296 K) | EPR of Irradiated Bovine Bone Collagen (296 K) | EPR of Polymer-Derived SiCN Ceramics (296 K) |
EPR of Υ -Irradiated Polymers | EPR of Irradiated Food Materials | EPR of Tooth and Bones |
EPR Spectra of Less Common Samples : | ||
EPR of Manganese Complex | EPR of Gadolinium Complex (MRI Contrast Agents) | EPR of Defect Centers in Silica |
EPR of Ferromagnetc Samples | EPR of Vanadium Complexes | EPR of Coals |
EPR of Vitamin Tablets | ESR of Whisky and Beers | EPR of Antioxidants and TEMPOL |
Contact us for Multinuclear and Free-radical EPR/ESR Spectral Analysis and Consulting for a wide variety of materials at reasonable cost….