Double Electron Electron Resonance
Double Electron Electron Resonance - Related Videos
11:07
Electron Paramagnetic Resonance (EPR) Spectroscopy
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2023
Source: David C. Powers, Tamara M. Powers, Texas A&M In this video, we will learn the basic principles behind Electron Paramagnetic Resonance (EPR). We will use EPR spectroscopy to study how dibutylhydroxy toluene (BHT) behaves as an antioxidant in the autoxidation of aliphatic aldehydes.
08:01
Rapid Scan Electron Paramagnetic Resonance Opens New Avenues for Imaging Physiologically Important Parameters In Vivo
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Cited by 11 •
2016
A new electron paramagnetic resonance (EPR) method, rapid scan EPR (RS-EPR), is demonstrated for 2D spectral spatial imaging which is superior to the traditional continuous wave (CW) technique and opens new venues for in vivo imaging. Results are demonstrated at 250 MHz, but the technique is applicable at any frequency.
09:40
Electron Spin Resonance Micro-imaging of Live Species for Oxygen Mapping
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Cited by 3 •
2010
This protocol describes a method for micron-scale three-dimensional imaging of oxygen concentration in the immediate environment of live cells by electron spin resonance microscopy.
01:24
Electron Carriers
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2019
Electron carriers can be thought of as electron shuttles. These compounds can easily accept electrons (i.e., be reduced) or lose them (i.e., be oxidized). They play an essential role in energy production because cellular respiration is contingent on the flow of electrons. Over the many stages of cellular respiration, glucose breaks down into carbon dioxide and water. Electron carriers pick up electrons lost by glucose in these reactions, temporarily storing and releasing them into the electron...
03:07
Electron Affinity
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2020
The electron affinity (EA) is the energy change for adding an electron to a gaseous atom to form an anion (negative ion). This process can be either endothermic or exothermic, depending on the element. Many of these elements have negative values of EA, which means that energy is released when the gaseous atom accepts an electron. However, for some elements, energy is required for the atom to become negatively charged, and the value of their EA is positive. Just as with ionization energy,...
FAQs
Dipolar coupling creates a distance-dependent modulation in the detected signal. DEER observes how the signal from one unpaired electron spin changes when another spin is selectively excited, then relates that modulation to the separation between the spins. The resulting analysis produces a distance distribution rather than only a single structural value, which is useful for heterogeneous molecular systems.
Selective microwave excitation distinguishes the spin being observed from the second spin whose state is deliberately changed. The resulting perturbation allows the experiment to isolate how interactions between the two unpaired electrons affect the measured signal. This separation is essential because the observed modulation carries the information used to determine spin-spin distances.
A molecular sample may contain several conformations with different separations between its unpaired electron spins. Instead of forcing these structures into one average distance, DEER can represent the measurement as a distribution of distances. Changes in that distribution can therefore indicate structural variation or conformational changes in spin-labeled molecules and paramagnetic complexes.
DEER supplies experimentally measured distance information between unpaired electron spins, whereas crystallography and computational modeling provide complementary structural perspectives. The techniques can be combined to evaluate molecular arrangements, test proposed conformations, and interpret structural changes. In chemistry, this combination is especially relevant when studying reaction mechanisms or systems whose structures can change.
The method can be applied to spin-labeled molecules, paramagnetic metal complexes, and materials containing suitable unpaired electron spins. These systems allow researchers to investigate molecular structure, interactions, and conformational changes through their spin-spin relationships. Its usefulness therefore extends across molecular chemistry and materials-oriented studies rather than being limited to one compound class.
A DEER measurement provides distance distributions that can be compared across different molecular states or experimental conditions. Such comparisons can reveal structural rearrangements, changes in conformation, or altered interactions within a system. When paired with spectroscopy, crystallography, or computational modeling, the results can help connect these structural changes with reaction mechanisms and other dynamic chemical behavior.