Questions tagged [epr-spectroscopy]

This tag should be applied to questions concerning all aspects of electron paramagnetic resonance (EPR) spectroscopy, including the theory behind the technique and its applications in chemistry.

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Can two S=1/2 centers have J and D parameters simultaneously?

I am new to EPR/ESR and need some help in connecting theory with a published experimental data. Following is my query. What I understood from EPR theory is that two active EPR centers with S=1/2 ...
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What is the paramagnetic susceptibility of sodium at around room temperature?

Proposed solution: This question comes from Tanner's manual Introduction to the Physics of Electrons in Solids, at the chapter dedicated to the application of the Fermi gas model. The Fermi energy is $...
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On the definition of eigenframe

While reading the following article, Elizaveta A. Suturina, Kevin Mason, Carlos F. G. C. Geraldes, Ilya Kuprov, David Parker, Beyond Bleaney's theory: experimental and theoretical analysis of ...
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How can Spin-Orbit-Coupling allow interactions between states with different multiplicities?

I can understand how spin-orbit coupling generates the hyperfine structures that we see in textbooks but maybe my view that the L + S momenta interacting to generate a third J momentum is too ...
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Is there any magnetic resonance spectroscopy that based on orbital angular momentum?

The different momenta of electron and nucleus are described by different quantum numbers. (a) l and m$_l$ describe the orbital angular momentum and quantization on its component along an arbitrary ...
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g-tensor and hyperfine tensor for nitroxide spin label with 15N

Does anyone know where I can find numerical data for the $g$ tensor and hyperfine tensor for a nitroxide spin label where the nitrogen-14 atom has been replaced by a nitrogen-15 atom? I'm really ...
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Can % location of electron on metal or ligand be negative (EPR)?

Given an EPR spectrum of [Co(3-methoxysalen)(py)] : and equations: A(x) = A(iso) + B A(z) = A(iso) - 2B %Co in SOMO = B/B0 where A(x) and A(z) are hyperfine coupling constants measured from the ...
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What is a possible conventional interpretation of Wilfred Hagen's puzzling Electron Paramagnetic Resonance spectrum?

In searching for a conventional interpretation, Wilfred Hagen of Delft Technical University is stumped by an Electron Paramagnetic Resonance spectrum (aka Electron Spin Resonance spectrum) in "...
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Effect of transition energy gap and frequency of microwave on appearance of CW EPR spectrum

Consider continuous-wave EPR for species with only one unpaired electron in the following argument. The interaction energy in the presence of external magnetic field of strength B is given by $$E = Bg\...
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How to turn oil into in a gel?

I've seen some EPR experiments where they add gelatin to water with spin-probes in it, as it "hardens" it immobilizes the spin-probes so that you can check effect of tumbling rate on the EPR....
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Measured g-factor of a free-radical changing as a function of something. But I cant work out what?

I'm looking at EPR of a paramagnetic organic molecule in solution that has a very stable free-radical signature with gfactor ~2.0035. All good. Except when watching one particular experiment I saw ...
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Grasping the concept of Electronic Spin, Effective Spin and Fictitious Spin

Trying to learn alone some aspects of quantum mechanics is, sometimes, a struggle. Reading the excellent paper by Piwowarska [1] I was hoping to, finally, understand what is the origin of the so-...
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Handling EPR spin-probes, specifically how to dissolve 5-DSA?

I want to do some EPR tests with 5-DSA (or related spin probe) dissolved into different crude oils. It had not sunk into me that $100 of 5-DSA was a tiny amount of a very sticky solid. It's proving ...
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2 votes
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EPR or NMR sample that will give narrow lines at 4 K

We have made a crossed coil setup (X and Y transmit/receiving coils) with a SQUID pick up loop along Z. Now we want to see EPR or NMR lines, probably using it in a CW fashion, ie. putting a ramp + ...
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How to calculate the magnetic exchange coupling in a charged radical complex?

I have a neutral complex with two magnetic centers. For this case it is easy to calculate the exchange coupling as the broken symmetry state is converged properly. But when I am making the complex ...
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Directionality of ring current-induced magnetic fields in purines

What would be the directions of ring current-induced magnetic fields in purine-like heterocycles in a ​strong magnetic field? Would be the antiparallel state be a default state for these substances in ...
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7 votes
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Can one figure out an optical absorption spectrum from EPR data?

I'm wondering if it's worthwhile for me as an optical spectroscopist to read up a bit on EPR. Do EPR signals reveal where, in terms of wavelength, features in the optical spectrum can be expected to ...
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Factors to consider to predict EPR

What are the factors to consider when predicting the EPR spectrum of $\ce{Cu(Ox)P(CH3)3}$ where $\ce{OX}$ is the oxalate ion? I understand that there are several factors to consider for EPR (Electron ...
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